green house effects

8/12/2019 Green House Effects

1/64

A greenhouse (also called a glasshouse) is a building in whichplants are grown.

These structures range in size from small sheds to industrial-sized buildings. A

miniature greenhouse is known as acold frame.

Commercial glass greenhouses are often high tech production facilities for

vegetables or flowers. The glass greenhouses are filled with equipment like

screening installations, heating, cooling, lighting and may be automatically

controlled by a computer.

A greenhouse is a structural building with different types of covering materials,

such as aglass orplastic roof and frequently glass or plastic walls; it heats up

because incoming visible sunshine is absorbed inside the structure. Air warmed by

the heat from warmed interior surfaces is retained in the building by the roof and

wall; the air that is warmed near the ground is prevented from rising indefinitely

and flowing away. This is not the same mechanism as the "greenhouse effect".

Types[edit]
http://en.wikipedia.org/wiki/Planthttp://en.wikipedia.org/wiki/Cold_framehttp://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Plastichttp://en.wikipedia.org/wiki/Greenhouse_effect#Real_greenhouseshttp://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=1http://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=1http://en.wikipedia.org/wiki/Greenhouse_effect#Real_greenhouseshttp://en.wikipedia.org/wiki/Plastichttp://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Cold_framehttp://en.wikipedia.org/wiki/Plant


2/64

Greenhouses can be divided into glass greenhouses and plastic greenhouses.

Plastics mostly used arepolyethylene film and multiwall sheets

ofpolycarbonate material, or PMMAacrylic glass.Commercial glass greenhouses

are often high-tech production facilities for vegetables or flowers. The glass

greenhouses are filled with equipment such as screening installations, heating,

cooling and lighting, and may be automatically controlled by a computer.

Uses[edit]

Greenhouses allow for greater control over the growing environment of plants.

Depending upon the technical specification of a greenhouse, key factors which

may be controlled include temperature, levels of light and

shade,irrigation,fertilizer application, and atmospheric humidity. Greenhouses

may be used to overcome shortcomings in the growing qualities of a piece of land,

such as a short growing season or poor light levels, and they can thereby improve

food production in marginal environments.

The greenhouses complex in theprovince of Almera,Andaluca,Spain,is visible

from space.[3]

As they may enable certain crops to be grown throughout the year, greenhouses are

increasingly important in the food supply of high-latitude countries. One of the
http://en.wikipedia.org/wiki/Polyethylenehttp://en.wikipedia.org/wiki/Polycarbonatehttp://en.wikipedia.org/wiki/Acrylic_glasshttp://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=2http://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Province_of_Almer%C3%ADahttp://en.wikipedia.org/wiki/Andaluc%C3%ADahttp://en.wikipedia.org/wiki/Spainhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-3http://en.wikipedia.org/wiki/Greenhouse#cite_note-3http://en.wikipedia.org/wiki/Greenhouse#cite_note-3http://en.wikipedia.org/wiki/File:Almeria-Invernaderos.jpghttp://en.wikipedia.org/wiki/File:Almeria-Invernaderos.jpghttp://en.wikipedia.org/wiki/File:Almeria-Invernaderos.jpghttp://en.wikipedia.org/wiki/File:Almeria-Invernaderos.jpghttp://en.wikipedia.org/wiki/Greenhouse#cite_note-3http://en.wikipedia.org/wiki/Spainhttp://en.wikipedia.org/wiki/Andaluc%C3%ADahttp://en.wikipedia.org/wiki/Province_of_Almer%C3%ADahttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=2http://en.wikipedia.org/wiki/Acrylic_glasshttp://en.wikipedia.org/wiki/Polycarbonatehttp://en.wikipedia.org/wiki/Polyethylene


3/64

largest complexes in the world is inAlmera,Andaluca,Spain,where greenhouses

cover almost 50,000 acres (200 km2).[4]

Greenhouses are often used for growingflowers,vegetables,fruits,andtransplants.

Special greenhouse varieties of certain crops, such as tomatoes, are generally used

for commercial production. Many vegetables and flowers can be grown in

greenhouses in late winter and early spring, and then transplanted outside as the

weather warms.Bumblebees are thepollinators of choice for

mostpollination,[citation needed]although other types ofbees have been used, as well as

artificial pollination.Hydroponics can be used to make the most use of the interior

space.

The relatively closed environment of a greenhouse has its own unique management

requirements, compared with outdoor production.Pests anddiseases,and extremes

of heat and humidity, have to be controlled, and irrigation is necessary to provide

water. Most greenhouses use sprinklers or drip lines. Significant inputs of heat and

light may be required, particularly with winter production of warm-weather

vegetables.

Greenhouses also have applications outside of the agriculture industry. GlassPoint

Solar, located in Fremont, CA, encloses solar fields in greenhouses to produce

steam forsolar-enhanced oil recovery.[5]

Alpine house[edit]

An "alpine house" is a specialized greenhouse used for growingalpine plants.The

purpose of an alpine house is to mimic the conditions in which alpine plants grow;

particularly to provide protection from wet conditions in winter. Alpine houses are

often unheated, since the plants grown there are hardy, or require at most
http://en.wikipedia.org/wiki/Province_of_Almer%C3%ADahttp://en.wikipedia.org/wiki/Andaluc%C3%ADahttp://en.wikipedia.org/wiki/Spainhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-4http://en.wikipedia.org/wiki/Greenhouse#cite_note-4http://en.wikipedia.org/wiki/Greenhouse#cite_note-4http://en.wikipedia.org/wiki/Floriculturehttp://en.wikipedia.org/wiki/Vegetablehttp://en.wikipedia.org/wiki/Fruithttp://en.wikipedia.org/wiki/Transplantinghttp://en.wikipedia.org/wiki/Bumblebeehttp://en.wikipedia.org/wiki/Pollinatorhttp://en.wikipedia.org/wiki/Pollinationhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Beehttp://en.wikipedia.org/wiki/Hydroponicshttp://en.wikipedia.org/wiki/Pest_(animal)http://en.wikipedia.org/wiki/Diseasehttp://en.wikipedia.org/wiki/Solar_Enhanced_Oil_Recoveryhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-5http://en.wikipedia.org/wiki/Greenhouse#cite_note-5http://en.wikipedia.org/wiki/Greenhouse#cite_note-5http://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=3http://en.wikipedia.org/wiki/Alpine_planthttp://en.wikipedia.org/wiki/Alpine_planthttp://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=3http://en.wikipedia.org/wiki/Greenhouse#cite_note-5http://en.wikipedia.org/wiki/Solar_Enhanced_Oil_Recoveryhttp://en.wikipedia.org/wiki/Diseasehttp://en.wikipedia.org/wiki/Pest_(animal)http://en.wikipedia.org/wiki/Hydroponicshttp://en.wikipedia.org/wiki/Beehttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Pollinationhttp://en.wikipedia.org/wiki/Pollinatorhttp://en.wikipedia.org/wiki/Bumblebeehttp://en.wikipedia.org/wiki/Transplantinghttp://en.wikipedia.org/wiki/Fruithttp://en.wikipedia.org/wiki/Vegetablehttp://en.wikipedia.org/wiki/Floriculturehttp://en.wikipedia.org/wiki/Greenhouse#cite_note-4http://en.wikipedia.org/wiki/Spainhttp://en.wikipedia.org/wiki/Andaluc%C3%ADahttp://en.wikipedia.org/wiki/Province_of_Almer%C3%ADa


4/64


5/64

Cucumbers were planted in wheeled carts which were put in the sun daily, then

taken inside to keep them warm at night. The cucumbers were stored under frames

or in cucumber houses glazed with either oiled cloth known as speculariaor with

sheets ofselenite (a.k.a. lapis specularis), according to the description byPliny the

Elder.[7]

In the 13th century, greenhouses were built inItaly[8]to house the exotic plants that

explorers brought back from thetropics. They were originally calledgiardini

botanici(botanical gardens).

Active greenhouses, in which it is possible for the temperature to be increased or

decreased manually, appeared much later.Sanga yorok written in the year 1450

AD inKorea, contained descriptions of a greenhouse, which was designed to

regulate the temperature and humidity requirements of plants and crops. One of the

earliest records of theAnnals of the Joseon Dynasty in 1438 confirms

growingmandarin trees in a Korean traditional greenhouse during the winter and

installing a heating system ofOndol.[9]

The concept of greenhouses also appeared inNetherlands and thenEngland in the

17th century, along with the plants. Some of these early attempts required

enormous amounts of work to close up at night or to winterize. There were serious

problems with providing adequate and balanced heat in these early greenhouses.

Today, the Netherlands has many of the largest greenhouses in the world, some of

them so vast that they are able to produce millions of vegetables every year.

The French botanistCharles Lucien Bonaparte is often credited with building the

first practical modern greenhouse inLeiden, Holland during the 1800s to grow

medicinal tropical plants.[10]Originally only on the estates of the rich, the growth

of the science ofbotany caused greenhouses to spread to the universities. The

French called their first greenhouses orangeries, since they were used to protect
http://en.wikipedia.org/wiki/Selenite_(mineral)http://en.wikipedia.org/wiki/Pliny_the_Elderhttp://en.wikipedia.org/wiki/Pliny_the_Elderhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-7http://en.wikipedia.org/wiki/Greenhouse#cite_note-7http://en.wikipedia.org/wiki/Greenhouse#cite_note-7http://en.wikipedia.org/wiki/Italyhttp://en.wikipedia.org/wiki/Italyhttp://en.wikipedia.org/wiki/Italyhttp://en.wikipedia.org/wiki/Tropicshttp://en.wikipedia.org/wiki/Sanga_yorokhttp://en.wikipedia.org/wiki/Koreahttp://en.wikipedia.org/wiki/Annals_of_the_Joseon_Dynastyhttp://en.wikipedia.org/wiki/Mandarin_orangehttp://en.wikipedia.org/wiki/Ondolhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-9http://en.wikipedia.org/wiki/Greenhouse#cite_note-9http://en.wikipedia.org/wiki/Greenhouse#cite_note-9http://en.wikipedia.org/wiki/Netherlandshttp://en.wikipedia.org/wiki/Englandhttp://en.wikipedia.org/wiki/Charles_Lucien_Bonapartehttp://en.wikipedia.org/wiki/Leidenhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-10http://en.wikipedia.org/wiki/Greenhouse#cite_note-10http://en.wikipedia.org/wiki/Greenhouse#cite_note-10http://en.wikipedia.org/wiki/Botanyhttp://en.wikipedia.org/wiki/Botanyhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-10http://en.wikipedia.org/wiki/Leidenhttp://en.wikipedia.org/wiki/Charles_Lucien_Bonapartehttp://en.wikipedia.org/wiki/Englandhttp://en.wikipedia.org/wiki/Netherlandshttp://en.wikipedia.org/wiki/Greenhouse#cite_note-9http://en.wikipedia.org/wiki/Ondolhttp://en.wikipedia.org/wiki/Mandarin_orangehttp://en.wikipedia.org/wiki/Annals_of_the_Joseon_Dynastyhttp://en.wikipedia.org/wiki/Koreahttp://en.wikipedia.org/wiki/Sanga_yorokhttp://en.wikipedia.org/wiki/Tropicshttp://en.wikipedia.org/wiki/Italyhttp://en.wikipedia.org/wiki/Italyhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-7http://en.wikipedia.org/wiki/Pliny_the_Elderhttp://en.wikipedia.org/wiki/Pliny_the_Elderhttp://en.wikipedia.org/wiki/Selenite_(mineral)


6/64

orange trees from freezing. As pineapples became popular,pineries, orpineapple

pits,were built.

Experimentation with the design of greenhouses continued during the 17th century

in Europe, as technology produced better glass and construction techniques

improved. The greenhouse at thePalace of Versailles was an example of their size

and elaborateness; it was more than 500 feet (150 m) long, 42 feet (13 m) wide,

and 45 feet (14 m) high.

The golden era of the greenhouse was in England during the Victorian era, where

the largest glasshouses yet conceived were constructed, as the wealthy upper class

and aspiring botanists competed to build the most elaborate buildings. A good

example of this trend is the pioneeringKew Gardens. Joseph Paxton, who had

experimented with glass and iron in the creation of large greenhouses as the head

gardener atChatsworth, inDerbyshire, working for theDuke of Devonshire,

designed and builtThe Crystal Palace inLondon, (although the latter was

constructed for both horticultural and non-horticultural exhibition).

Other large greenhouses built in the 19th century, included theNew York Crystal

Palace,MunichsGlaspalast and theRoyal Greenhouses of Laeken (18741895)

forKing Leopold II of Belgium.

In Japan, the first greenhouse was built in 1880 bySamuel Cocking, a British

merchant who exportedherbs.

In the 20th century, thegeodesic dome was added to the many types of

greenhouses. Notable examples are theEden Project, inCornwall,The Rodale

Institute[11]in Pennsylvania, theClimatron at theMissouri Botanical Garden in St.

Louis, Missouri, andToyota Motor Manufacturing Kentucky.[12]
http://en.wikipedia.org/wiki/Pineapple_Pithttp://en.wikipedia.org/wiki/Pineapple_Pithttp://en.wikipedia.org/wiki/Palace_of_Versailleshttp://en.wikipedia.org/wiki/Kew_Gardenshttp://en.wikipedia.org/wiki/Chatsworth_Househttp://en.wikipedia.org/wiki/Derbyshirehttp://en.wikipedia.org/wiki/Duke_of_Devonshirehttp://en.wikipedia.org/wiki/The_Crystal_Palacehttp://en.wikipedia.org/wiki/Londonhttp://en.wikipedia.org/wiki/Exhibition_of_the_Industry_of_All_Nationshttp://en.wikipedia.org/wiki/Exhibition_of_the_Industry_of_All_Nationshttp://en.wikipedia.org/wiki/Munichhttp://en.wikipedia.org/wiki/Munichhttp://en.wikipedia.org/wiki/Glaspalast_(Munich)http://en.wikipedia.org/wiki/Royal_Greenhouses_of_Laekenhttp://en.wikipedia.org/wiki/King_Leopold_II_of_Belgiumhttp://en.wikipedia.org/wiki/Samuel_Cockinghttp://en.wikipedia.org/wiki/Herbhttp://en.wikipedia.org/wiki/Geodesic_domehttp://en.wikipedia.org/wiki/Eden_Projecthttp://en.wikipedia.org/wiki/Cornwallhttp://en.wikipedia.org/wiki/The_Rodale_Institutehttp://en.wikipedia.org/wiki/The_Rodale_Institutehttp://en.wikipedia.org/wiki/Greenhouse#cite_note-11http://en.wikipedia.org/wiki/Greenhouse#cite_note-11http://en.wikipedia.org/wiki/Climatronhttp://en.wikipedia.org/wiki/Missouri_Botanical_Gardenhttp://en.wikipedia.org/wiki/Toyota_Motor_Manufacturing_Kentuckyhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-12http://en.wikipedia.org/wiki/Greenhouse#cite_note-12http://en.wikipedia.org/wiki/Greenhouse#cite_note-12http://en.wikipedia.org/wiki/Greenhouse#cite_note-12http://en.wikipedia.org/wiki/Toyota_Motor_Manufacturing_Kentuckyhttp://en.wikipedia.org/wiki/Missouri_Botanical_Gardenhttp://en.wikipedia.org/wiki/Climatronhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-11http://en.wikipedia.org/wiki/The_Rodale_Institutehttp://en.wikipedia.org/wiki/The_Rodale_Institutehttp://en.wikipedia.org/wiki/Cornwallhttp://en.wikipedia.org/wiki/Eden_Projecthttp://en.wikipedia.org/wiki/Geodesic_domehttp://en.wikipedia.org/wiki/Herbhttp://en.wikipedia.org/wiki/Samuel_Cockinghttp://en.wikipedia.org/wiki/King_Leopold_II_of_Belgiumhttp://en.wikipedia.org/wiki/Royal_Greenhouses_of_Laekenhttp://en.wikipedia.org/wiki/Glaspalast_(Munich)http://en.wikipedia.org/wiki/Munichhttp://en.wikipedia.org/wiki/Exhibition_of_the_Industry_of_All_Nationshttp://en.wikipedia.org/wiki/Exhibition_of_the_Industry_of_All_Nationshttp://en.wikipedia.org/wiki/Londonhttp://en.wikipedia.org/wiki/The_Crystal_Palacehttp://en.wikipedia.org/wiki/Duke_of_Devonshirehttp://en.wikipedia.org/wiki/Derbyshirehttp://en.wikipedia.org/wiki/Chatsworth_Househttp://en.wikipedia.org/wiki/Kew_Gardenshttp://en.wikipedia.org/wiki/Palace_of_Versailleshttp://en.wikipedia.org/wiki/Pineapple_Pithttp://en.wikipedia.org/wiki/Pineapple_Pit


7/64

Greenhouse structures adapted in the 1960s when wider sheets of polyethylene

film became widely available. Hoop houses were made by several companies and

were also frequently made by the growers themselves. Constructed of aluminum

extrusions, special galvanized steel tubing, or even just lengths of steel or PVC

water pipe, construction costs were greatly reduced. This resulted in many more

greenhouses being constructed on smaller farms and garden centers. Polyethylene

film durability increased greatly when more effective UV-inhibitors were

developed and added in the 1970s; these extended the usable life of the film from

one or two years up to 3 and eventually 4 or more years.

Gutter-connected greenhouses became more prevalent in the 1980s and 1990s.

These greenhouses have two or more bays connected by a common wall, or row of

support posts. Heating inputs were reduced as the ratio of floor area to roof area

was increased substantially.[clarification needed]Gutter-connected greenhouses are now

commonly used both in production and in situations where plants are grown and

sold to the public as well. Gutter-connected greenhouses are commonly covered

with structured polycarbonate materials, or a double layer of polyethylene film

with air blown between to provide increased heating efficiencies.

A plastic air-insulated greenhouse inNew Zealand
http://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/New_Zealandhttp://en.wikipedia.org/wiki/File:Greenhouse_New_Zealand.JPGhttp://en.wikipedia.org/wiki/New_Zealandhttp://en.wikipedia.org/wiki/Wikipedia:Please_clarify


8/64

Giant greenhouses in theNetherlands

TheNetherlands has some of the largest greenhouses in the world. Such is the

scale of food production in the country that in 2000, greenhouses occupied 10,526

hectares, or 0.25% of the total land area.[citation needed]

Greenhouses began to be built in theWestland area of the Netherlands in the mid-

19th century. The addition of sand to bogs and clay soil created fertile soil for

agriculture, and around 1850, grapes were grown in the first greenhouses, simple

glass constructions with one of the sides consisting of a solid wall. By the early

20th century, greenhouses began to be constructed with all sides built using glass,

and they began to be heated. This also allowed for the production of fruits and

vegetables that did not ordinarily grow in the area. Today, the Westland and the

area aroundAalsmeer have the highest concentration of greenhouse agriculture in

the world.[citation needed]The Westland produces mostly vegetables, besides plants and

flowers; Murno Gladst is noted mainly for the production of flowers and potted

plants. Since the 20th century, the area aroundVenlo and parts ofDrenthe have

also become important regions for greenhouse agriculture.

Since 2000, technical innovations include the "closed greenhouse", a completely

closed system allowing the grower complete control over the growing process
http://en.wikipedia.org/wiki/Netherlandshttp://en.wikipedia.org/wiki/Netherlandshttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Westland_(region),_Netherlandshttp://en.wikipedia.org/wiki/Aalsmeerhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Venlohttp://en.wikipedia.org/wiki/Drenthehttp://en.wikipedia.org/wiki/File:Westland_s-gravenzande_2.jpghttp://en.wikipedia.org/wiki/Drenthehttp://en.wikipedia.org/wiki/Venlohttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Aalsmeerhttp://en.wikipedia.org/wiki/Westland_(region),_Netherlandshttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Netherlandshttp://en.wikipedia.org/wiki/Netherlands


9/64

while using less energy. Floating greenhouses[clarification needed] are used in watery

areas of the country.

Young tomatoes in an industrial-sized greenhouse in the Netherlands

The Netherlands has around 9,000 greenhouse enterprises that operate over 10,000

hectares of greenhouses and employ some 150,000 workers, efficiently producing

4.5 billion worth of vegetables, fruit, plants, and flowers, some 80% of which is

exported.[citation needed]

Greenhouse ventilation[edit]

Ventilation is one of the most important components in a successful greenhouse. If

there is no proper ventilation, greenhouses and their plants can become prone to

problems. The main purposes of ventilation are to regulate the temperature to the

optimal level, and to ensure movement of air and thus prevent build-up of plant

pathogens (such asBotrytis cinerea) that prefer still air conditions. Ventilation also

ensures a supply of fresh air for photosynthesis and plantrespiration, and mayenable important pollinators to access the greenhouse crop.

Ventilation can be achieved via use of vents - often controlled automatically - and

recirculation fans.
http://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=6http://en.wikipedia.org/wiki/Ventilation_(architecture)http://en.wikipedia.org/wiki/Botrytis_cinereahttp://en.wikipedia.org/wiki/Botrytis_cinereahttp://en.wikipedia.org/wiki/Cellular_respirationhttp://en.wikipedia.org/wiki/File:TomateJungpflanzenAnzuchtNiederlande.jpghttp://en.wikipedia.org/wiki/File:TomateJungpflanzenAnzuchtNiederlande.jpghttp://en.wikipedia.org/wiki/File:TomateJungpflanzenAnzuchtNiederlande.jpghttp://en.wikipedia.org/wiki/File:TomateJungpflanzenAnzuchtNiederlande.jpghttp://en.wikipedia.org/wiki/Cellular_respirationhttp://en.wikipedia.org/wiki/Botrytis_cinereahttp://en.wikipedia.org/wiki/Ventilation_(architecture)http://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=6http://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Please_clarify


10/64

Greenhouse heating[edit]

Heating is one of the most considerable costs in the operation of greenhouses

across the globe, especially in colder climates. The main problem with heating a

greenhouse as opposed to a building that has solid opaque walls is the amount of

heat lost through the greenhouse covering. Since the coverings need to allow light

to filter into the structure, they conversely cannot insulate very well. With

traditional plastic greenhouse coverings having an R-Value of around 2, a great

amount of money is therefore spent to continually replace the heat lost. Most

greenhouses, when supplemental heat is needed use natural gas or electrical

furnaces.

Passive heating methods exist which seek heat using low energy input. Solar

energy can be captured from periods of relative abundance (day time/ summer),

and released boost the temperature during cooler periods (night time/winter).

Waste heat from livestock can also be used to heat greenhouses; e.g. placing a

chicken coop inside a greenhouse recovers the heat generated by the chickens,

which would otherwise be wasted.

Electronic controllers are often used to monitor the temperature and adjusts the

furnace operation to the conditions. This can be as simple as a basic thermostat, but

can be more complicated in larger greenhouse operations.

Greenhouse carbon dioxide enrichment[edit]

The possibility of using carbon dioxide enrichment in greenhouse cultivation to

enhance plant growth has been known for nearly 100 years.[13][14][15]After the

development of equipment for the controlled serial enrichment of carbon dioxide,

the technique was established on a broad scale in the Netherlands.[16]Secondary

metabolites, e. g. cardiac glycosides inDigitalis lanata, are produced in higher
http://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=7http://en.wikipedia.org/wiki/Heatinghttp://en.wikipedia.org/wiki/Solar_thermal_collectorhttp://en.wikipedia.org/wiki/Solar_thermal_collectorhttp://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=8http://en.wikipedia.org/wiki/Greenhouse#cite_note-13http://en.wikipedia.org/wiki/Greenhouse#cite_note-13http://en.wikipedia.org/wiki/Greenhouse#cite_note-15http://en.wikipedia.org/wiki/Greenhouse#cite_note-15http://en.wikipedia.org/wiki/Greenhouse#cite_note-16http://en.wikipedia.org/wiki/Greenhouse#cite_note-16http://en.wikipedia.org/wiki/Greenhouse#cite_note-16http://en.wikipedia.org/wiki/Digitalis_lanatahttp://en.wikipedia.org/wiki/Digitalis_lanatahttp://en.wikipedia.org/wiki/Greenhouse#cite_note-16http://en.wikipedia.org/wiki/Greenhouse#cite_note-15http://en.wikipedia.org/wiki/Greenhouse#cite_note-13http://en.wikipedia.org/wiki/Greenhouse#cite_note-13http://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=8http://en.wikipedia.org/wiki/Solar_thermal_collectorhttp://en.wikipedia.org/wiki/Solar_thermal_collectorhttp://en.wikipedia.org/wiki/Heatinghttp://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=7


11/64

amounts by greenhouse cultivation at enhanced temperature and at enhanced

carbon dioxide concentration.[17]Commercial greenhouses are now frequently

located near appropriate industrial facilities for mutual benefit. For example,

Cornerways Nursery in the UK is strategically placed near a major sugar

refinery,[18]consuming both waste heat and CO2 from the refinery which would

otherwise be vented to atmosphere. The refinery reduces its carbon emissions,

whilst the nursery enjoys boosted tomato yields and does not need to provide its

own greenhouse heating.

Greenhouse manufacturers[edit]

Lord & Burnhamfounded in 1849, the company was acquired by the UnderGlass Manufacturing Corporation in 1989, which continues to manufacture

Lord & Burnham brand greenhouses and solariums.[19]

Growing Spaces founded in 1989 in Colorado, manufactures geodesic domegreenhouses.[20]
http://en.wikipedia.org/wiki/Greenhouse#cite_note-17http://en.wikipedia.org/wiki/Greenhouse#cite_note-17http://en.wikipedia.org/wiki/Greenhouse#cite_note-17http://en.wikipedia.org/wiki/Greenhouse#cite_note-18http://en.wikipedia.org/wiki/Greenhouse#cite_note-18http://en.wikipedia.org/wiki/Greenhouse#cite_note-18http://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=9http://en.wikipedia.org/wiki/Lord_%26_Burnhamhttp://en.wikipedia.org/wiki/Greenhouse#cite_note-19http://en.wikipedia.org/wiki/Greenhouse#cite_note-19http://en.wikipedia.org/wiki/Greenhouse#cite_note-19http://en.wikipedia.org/wiki/Greenhouse#cite_note-20http://en.wikipedia.org/wiki/Greenhouse#cite_note-20http://en.wikipedia.org/wiki/Greenhouse#cite_note-20http://en.wikipedia.org/wiki/Greenhouse#cite_note-20http://en.wikipedia.org/wiki/Greenhouse#cite_note-19http://en.wikipedia.org/wiki/Lord_%26_Burnhamhttp://en.wikipedia.org/w/index.php?title=Greenhouse&action=edit&section=9http://en.wikipedia.org/wiki/Greenhouse#cite_note-18http://en.wikipedia.org/wiki/Greenhouse#cite_note-17


12/64

The greenhouse effect is a process by which thermal radiation from a planetary

surface is absorbed by atmosphericgreenhouse gases, and is re-radiated in all

directions. Since part of this re-radiation is back towards the surface and the lower

atmosphere, it results in an elevation of the average surface temperature above

what it would be in the absence of the gases.[1][2]

Solar radiation at the frequencies ofvisible light largely passes through the

atmosphere to warm the planetary surface, which then emits this energy at the

lower frequencies ofinfraredthermal radiation. Infrared radiation is absorbed by

greenhouse gases, which in turn re-radiate much of the energy to the surface and

lower atmosphere. The mechanism is named after the effect of solar radiation

passing through glass and warming agreenhouse, but the way it retains heat is

fundamentally different as a greenhouse works by reducing airflow, isolating the

warm air inside the structure so that heat is not lost byconvection.[2][3][4]

If an ideal thermally conductiveblackbody was the same distance from the Sun as

the Earth is, it would have a temperature of about 5.3 C. However, since the Earth

reflects about 30%[5][6]

of the incoming sunlight, this idealized planet'seffectivetemperature (the temperature of a blackbody that would emit the same amount of

radiation) would be about 18 C.[7][8]The surface temperature of this hypothetical

planet is 33 C below Earth's actual surface temperature of approximately 14

C.[9]The mechanism that produces this difference between the actual surface

temperature and the effective temperature is due to the atmosphere and is known as

the greenhouse effect.[10]

Earths natural greenhouse effect makes life as we know it possible. However,

human activities, primarily the burning of fossil fuels and clearing of forests, have

intensified the natural greenhouse effect, causingglobal warming.[11]

Contents
http://en.wikipedia.org/wiki/Greenhouse_gashttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipccar4syr-1http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipccar4syr-1http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipccar4syr-1http://en.wikipedia.org/wiki/Lighthttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Greenhousehttp://en.wikipedia.org/wiki/Convectionhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipcc-AR4WG1-2http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipcc-AR4WG1-2http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Schroeder-4http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Schroeder-4http://en.wikipedia.org/wiki/Blackbodyhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-5http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-5http://en.wikipedia.org/wiki/Effective_temperaturehttp://en.wikipedia.org/wiki/Effective_temperaturehttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-7http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-7http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-7http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-9http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-9http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-9http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-10http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-10http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-10http://en.wikipedia.org/wiki/Global_warminghttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-11http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-11http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-11http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-11http://en.wikipedia.org/wiki/Global_warminghttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-10http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-9http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-7http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-7http://en.wikipedia.org/wiki/Effective_temperaturehttp://en.wikipedia.org/wiki/Effective_temperaturehttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-5http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-5http://en.wikipedia.org/wiki/Blackbodyhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Schroeder-4http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipcc-AR4WG1-2http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipcc-AR4WG1-2http://en.wikipedia.org/wiki/Convectionhttp://en.wikipedia.org/wiki/Greenhousehttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Lighthttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipccar4syr-1http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-ipccar4syr-1http://en.wikipedia.org/wiki/Greenhouse_gas


13/64

[hide]

1 History 2 Mechanism 3 Greenhouse gases 4 Role in climate change 5 Real greenhouses 6 Bodies other than Earth 7 See also 8 References 9 Further reading 10 External links

History

The existence of the greenhouse effect was argued for byJoseph Fourier in 1824.

The argument and the evidence was further strengthened byClaude Pouillet in

1827 and 1838, and reasoned from experimental observations byJohn Tyndall in1859, and more fully quantified bySvante Arrhenius in 1896.[12][13]

In 1917Alexander Graham Bell wrote [The unchecked burning of fossil fuels]

would have a sort of greenhouse effect, and The net result is the greenhouse

becomes a sort of hot-house.[14][15]Bell went on to also advocate for the use of

alternate energy sources, such assolar energy.[16]

Mechanism

The Earth receives energy from the Sun in the formUV,visible, andnear

IR radiation, most of which passes through theatmospherewithout being absorbed.

Of the total amount of energy available at the top of the atmosphere (TOA), about
http://en.wikipedia.org/wiki/Greenhouse_effecthttp://en.wikipedia.org/wiki/Greenhouse_effect#Historyhttp://en.wikipedia.org/wiki/Greenhouse_effect#Mechanismhttp://en.wikipedia.org/wiki/Greenhouse_effect#Greenhouse_gaseshttp://en.wikipedia.org/wiki/Greenhouse_effect#Role_in_climate_changehttp://en.wikipedia.org/wiki/Greenhouse_effect#Real_greenhouseshttp://en.wikipedia.org/wiki/Greenhouse_effect#Bodies_other_than_Earthhttp://en.wikipedia.org/wiki/Greenhouse_effect#See_alsohttp://en.wikipedia.org/wiki/Greenhouse_effect#Referenceshttp://en.wikipedia.org/wiki/Greenhouse_effect#Further_readinghttp://en.wikipedia.org/wiki/Greenhouse_effect#External_linkshttp://en.wikipedia.org/wiki/Joseph_Fourierhttp://en.wikipedia.org/wiki/Claude_Pouillethttp://en.wikipedia.org/wiki/John_Tyndallhttp://en.wikipedia.org/wiki/Svante_Arrheniushttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-anrev-12http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-anrev-12http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-anrev-12http://en.wikipedia.org/wiki/Alexander_Graham_Bellhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-DictionaryOfCanBiography-14http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-DictionaryOfCanBiography-14http://en.wikipedia.org/wiki/Solar_energyhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-G.26W3-16http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-G.26W3-16http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-G.26W3-16http://en.wikipedia.org/wiki/UVhttp://en.wikipedia.org/wiki/Visible_lighthttp://en.wikipedia.org/wiki/Near-infraredhttp://en.wikipedia.org/wiki/Near-infraredhttp://en.wikipedia.org/wiki/Atmospherehttp://en.wikipedia.org/wiki/Atmospherehttp://en.wikipedia.org/wiki/Near-infraredhttp://en.wikipedia.org/wiki/Near-infraredhttp://en.wikipedia.org/wiki/Visible_lighthttp://en.wikipedia.org/wiki/UVhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-G.26W3-16http://en.wikipedia.org/wiki/Solar_energyhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-DictionaryOfCanBiography-14http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-DictionaryOfCanBiography-14http://en.wikipedia.org/wiki/Alexander_Graham_Bellhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-anrev-12http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-anrev-12http://en.wikipedia.org/wiki/Svante_Arrheniushttp://en.wikipedia.org/wiki/John_Tyndallhttp://en.wikipedia.org/wiki/Claude_Pouillethttp://en.wikipedia.org/wiki/Joseph_Fourierhttp://en.wikipedia.org/wiki/Greenhouse_effect#External_linkshttp://en.wikipedia.org/wiki/Greenhouse_effect#Further_readinghttp://en.wikipedia.org/wiki/Greenhouse_effect#Referenceshttp://en.wikipedia.org/wiki/Greenhouse_effect#See_alsohttp://en.wikipedia.org/wiki/Greenhouse_effect#Bodies_other_than_Earthhttp://en.wikipedia.org/wiki/Greenhouse_effect#Real_greenhouseshttp://en.wikipedia.org/wiki/Greenhouse_effect#Role_in_climate_changehttp://en.wikipedia.org/wiki/Greenhouse_effect#Greenhouse_gaseshttp://en.wikipedia.org/wiki/Greenhouse_effect#Mechanismhttp://en.wikipedia.org/wiki/Greenhouse_effect#Historyhttp://en.wikipedia.org/wiki/Greenhouse_effect


14/64

50% is absorbed at the Earth's surface. Because it is warm, the surface radiates far

IR thermal radiation that consists of wavelengths that are predominantly much

longer than the wavelengths that were absorbed (the overlap between the incident

solar spectrum and the terrestrial thermal spectrum is small enough to be neglected

for most purposes). Most of this thermal radiation is absorbed by the atmosphere

and re-radiated both upwards and downwards; that radiated downwards is absorbed

by the Earth's surface. This trapping of long-wavelength thermal radiation leads to

a higher equilibrium temperature than if the atmosphere were absent.

This highly simplified picture of the basic mechanism needs to be qualified in a

number of ways, none of which affect the fundamental process.

Thesolar radiation spectrum for direct light at both the top of the Earth's

atmosphere and at sea level
http://en.wikipedia.org/wiki/Solar_radiationhttp://en.wikipedia.org/wiki/File:Synthetic_atmosphere_absorption_spectrum_2.gifhttp://en.wikipedia.org/wiki/File:Synthetic_atmosphere_absorption_spectrum_2.gifhttp://en.wikipedia.org/wiki/File:Solar_Spectrum.pnghttp://en.wikipedia.org/wiki/File:Solar_Spectrum.pnghttp://en.wikipedia.org/wiki/File:Synthetic_atmosphere_absorption_spectrum_2.gifhttp://en.wikipedia.org/wiki/File:Synthetic_atmosphere_absorption_spectrum_2.gifhttp://en.wikipedia.org/wiki/File:Solar_Spectrum.pnghttp://en.wikipedia.org/wiki/File:Solar_Spectrum.pnghttp://en.wikipedia.org/wiki/File:Synthetic_atmosphere_absorption_spectrum_2.gifhttp://en.wikipedia.org/wiki/File:Synthetic_atmosphere_absorption_spectrum_2.gifhttp://en.wikipedia.org/wiki/File:Solar_Spectrum.pnghttp://en.wikipedia.org/wiki/File:Solar_Spectrum.pnghttp://en.wikipedia.org/wiki/File:Synthetic_atmosphere_absorption_spectrum_2.gifhttp://en.wikipedia.org/wiki/File:Synthetic_atmosphere_absorption_spectrum_2.gifhttp://en.wikipedia.org/wiki/File:Solar_Spectrum.pnghttp://en.wikipedia.org/wiki/File:Solar_Spectrum.pnghttp://en.wikipedia.org/wiki/Solar_radiation


15/64

Synthetic stick absorption spectrum of a simple gas mixture corresponding to

theEarth's atmosphere composition based onHITRAN data[17]created using Hitran

on the Web system.[18]Green color - water vapor, red - carbon dioxide, WN -

wavenumber(caution: lowerwavelengths on the right, higher on the left).

The incoming radiation from the Sun is mostly in the form of visible light andnearby wavelengths, largely in the range 0.24 m, corresponding to the Sun's

radiative temperature of 6,000 K.[19]Almost half the radiation is in the form of

"visible" light, which our eyes are adapted to use.[20]

About 50% of the Sun's energy is absorbed at the Earth's surface and the rest isreflected or absorbed by the atmosphere. The reflection of light back into

spacelargely by cloudsdoes not much affect the basic mechanism; this

light, effectively, is lost to the system.

The absorbed energy warms the surface. Simple presentations of thegreenhouse effect, such as the idealized greenhouse model, show this heat

being lost as thermal radiation. The reality is more complex: the atmosphere

near the surface is largely opaque to thermal radiation (with important

exceptions for "window" bands), and most heat loss from the surface is

bysensible heat andlatent heat transport. Radiative energy losses become

increasingly important higher in the atmosphere largely because of the

decreasing concentration of water vapor, an important greenhouse gas. It is

more realistic to think of the greenhouse effect as applying to a "surface" in the

mid-troposphere,which is effectively coupled to the surface by alapse rate. The simple picture assumes a steady state. In the real world there is the diurnal

cycle as well as seasonal cycles and weather. Solar heating only applies during

daytime. During the night, the atmosphere cools somewhat, but not greatly,
http://en.wikipedia.org/wiki/Atmosphere_of_Earthhttp://en.wikipedia.org/wiki/HITRANhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-HITRAN-17http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-HITRAN-17http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-HITRAN-17http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-hitraniaoru-18http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-hitraniaoru-18http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-hitraniaoru-18http://en.wikipedia.org/wiki/Wavenumberhttp://en.wikipedia.org/wiki/Wavelengthhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Visible_proportion-20http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Visible_proportion-20http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Visible_proportion-20http://en.wikipedia.org/wiki/Idealized_greenhouse_modelhttp://en.wikipedia.org/wiki/Sensible_heathttp://en.wikipedia.org/wiki/Latent_heathttp://en.wikipedia.org/wiki/Tropospherehttp://en.wikipedia.org/wiki/Lapse_ratehttp://en.wikipedia.org/wiki/Diurnal_cyclehttp://en.wikipedia.org/wiki/Diurnal_cyclehttp://en.wikipedia.org/wiki/Diurnal_cyclehttp://en.wikipedia.org/wiki/Diurnal_cyclehttp://en.wikipedia.org/wiki/Lapse_ratehttp://en.wikipedia.org/wiki/Tropospherehttp://en.wikipedia.org/wiki/Latent_heathttp://en.wikipedia.org/wiki/Sensible_heathttp://en.wikipedia.org/wiki/Idealized_greenhouse_modelhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Visible_proportion-20http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Wavelengthhttp://en.wikipedia.org/wiki/Wavenumberhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-hitraniaoru-18http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-HITRAN-17http://en.wikipedia.org/wiki/HITRANhttp://en.wikipedia.org/wiki/Atmosphere_of_Earth


16/64

because its emissivity is low, and during the day the atmosphere

warms.Diurnal temperature changes decrease with height in the atmosphere.

Within the region where radiative effects are important the description given bythe idealized greenhouse model becomes realistic: The surface of the Earth,

warmed to a temperature around 255 K, radiates long-wavelength,infrared heat

in the range 4100 m.[19]At these wavelengths, greenhouse gases that were

largely transparent to incoming solar radiation are more absorbent.[19]Each

layer of atmosphere with greenhouses gases absorbs some of the heat being

radiated upwards from lower layers. It re-radiates in all directions, both

upwards and downwards; in equilibrium (by definition) the same amount as ithas absorbed. This results in more warmth below. Increasing the concentration

of the gases increases the amount of absorption and re-radiation, and thereby

further warms the layers and ultimately the surface below.[8]

Greenhouse gasesincluding most diatomic gases with two different atoms(such as carbon monoxide, CO) and all gases with three or more atomsare

able to absorb and emit infrared radiation. Though more than 99% of the dry

atmosphere is IR transparent (because the main constituentsN2, O2, and Ar

are not able to directly absorb or emit infrared radiation), intermolecular

collisions cause the energy absorbed and emitted by the greenhouse gases to be
http://en.wikipedia.org/wiki/Diurnal_temperature_variationhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-IPCC4_ch01-8http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-IPCC4_ch01-8http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-IPCC4_ch01-8http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-IPCC4_ch01-8http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Mitchell-1989-19http://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Diurnal_temperature_variation


17/64

shared with the other, non-IR-active, gases.

Greenhouse gases

Main article:Greenhouse gas

By their percentage contribution to the greenhouse effect on Earth the four major

gases are:[21][22]

water vapor,3670% carbon dioxide,926% methane,49% ozone,37%
http://en.wikipedia.org/wiki/Greenhouse_gashttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-realclimate.org-21http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-realclimate.org-21http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-realclimate.org-21http://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-realclimate.org-21http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-realclimate.org-21http://en.wikipedia.org/wiki/Greenhouse_gas


18/64


19/64

maxima (~300 ppm) from ice core data.[29]The effect of combustion-produced

carbon dioxide on the global climate, a special case of the greenhouse effect first

described in 1896 bySvante Arrhenius,has also been called theCallendar effect.

Over the past 800,000 years,[30]ice core data shows that carbon dioxide has varied

from values as low as 180 parts per million (ppm) to the pre-industrial level of

270ppm.[31]Paleoclimatologists consider variations in carbon dioxide

concentration to be a fundamental factor influencing climate variations over this

time scale.[32][33]

Real greenhouses

A modernGreenhouse inRHS Wisley

The "greenhouse effect" of the atmosphere is named by analogy to greenhouses

which get warmer in sunlight, but the mechanism by which the atmosphere retains

heat is different.[34]A greenhouse works primarily by preventing absorbed heat

from leaving the structure throughconvection, i.e.sensible heat transport. The

greenhouse effect heats the earth because greenhouse gases absorb outgoingradiative energy and re-emit some of it back towards earth.

A greenhouse is built of any material that passes sunlight, usually glass, or plastic.

It mainly heats up because the Sun warms the ground inside, which then warms the

air in the greenhouse. The air continues to heat because it is confined within the
http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-29http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-29http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-29http://en.wikipedia.org/wiki/Svante_Arrheniushttp://en.wikipedia.org/wiki/Callendar_effecthttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-30http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-30http://en.wikipedia.org/wiki/Carbon_dioxide#Variation_in_the_pasthttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-31http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-31http://en.wikipedia.org/wiki/Paleoclimatologistshttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Bowen_.282005.29.2C_Thin_Ice-32http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Bowen_.282005.29.2C_Thin_Ice-32http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Bowen_.282005.29.2C_Thin_Ice-32http://en.wikipedia.org/wiki/Greenhousehttp://en.wikipedia.org/wiki/Wisley_Gardenhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-34http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-34http://en.wikipedia.org/wiki/Convectionhttp://en.wikipedia.org/wiki/Sensible_heathttp://en.wikipedia.org/wiki/File:RHSGlasshouse.JPGhttp://en.wikipedia.org/wiki/File:RHSGlasshouse.JPGhttp://en.wikipedia.org/wiki/File:RHSGlasshouse.JPGhttp://en.wikipedia.org/wiki/File:RHSGlasshouse.JPGhttp://en.wikipedia.org/wiki/Sensible_heathttp://en.wikipedia.org/wiki/Convectionhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-34http://en.wikipedia.org/wiki/Wisley_Gardenhttp://en.wikipedia.org/wiki/Greenhousehttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Bowen_.282005.29.2C_Thin_Ice-32http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Bowen_.282005.29.2C_Thin_Ice-32http://en.wikipedia.org/wiki/Paleoclimatologistshttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-31http://en.wikipedia.org/wiki/Carbon_dioxide#Variation_in_the_pasthttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-30http://en.wikipedia.org/wiki/Callendar_effecthttp://en.wikipedia.org/wiki/Svante_Arrheniushttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-29


20/64

greenhouse, unlike the environment outside the greenhouse where warm air near

the surface rises and mixes with cooler air aloft. This can be demonstrated by

opening a small window near the roof of a greenhouse: the temperature will drop

considerably. It has also been demonstrated experimentally (R. W. Wood, 1909)

that a "greenhouse" with a cover ofrock salt (which is transparent to infra red)

heats up an enclosure similarly to one with a glass cover.[3]Thus greenhouses work

primarily by preventingconvective cooling.[4][35]

In contrast, the greenhouse effect heats the earth because rather than retaining

(sensible) heat by physically preventing movement of the air, greenhouse gases act

to warm the Earth by re-radiating some of the energy back towards the surface.

This process may exist in real greenhouses, but is comparatively unimportant there.

Bodies other than Earth

In the Solar System,Mars,Venus, and the moonTitan also exhibit greenhouse

effects; that on Venus is particularly large, due to its atmosphere, which consists

mainly of dense carbon dioxide[36]Titan has ananti-greenhouse effect,in that its

atmosphere absorbs solar radiation but is relatively transparent to infrared

radiation.Pluto also exhibits behavior superficially similar to the anti-greenhouse

effect.[37][38]

Arunaway greenhouse effect occurs ifpositive feedbacks lead to the evaporation

of all greenhouse gases into the atmosphere.[39]A runaway greenhouse effect

involving carbon dioxide and water vapor is thought to have occurred on Venus.[40]

nce the beginning of theIndustrial Revolution (taken as the year 1750), the burning

of fossil fuels and extensive clearing of native forests has contributed to a 40%

increase in the atmospheric concentration ofcarbon dioxide, from 280 to

392.6parts per million(ppm) in 2012.[5][6]This increase has occurred despite the
http://en.wikipedia.org/wiki/Robert_W._Woodhttp://en.wikipedia.org/wiki/Halitehttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-wood1909-3http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-wood1909-3http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-wood1909-3http://en.wikipedia.org/wiki/Convectionhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Schroeder-4http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Schroeder-4http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Schroeder-4http://en.wikipedia.org/wiki/Marshttp://en.wikipedia.org/wiki/Venus#Atmosphere_and_climatehttp://en.wikipedia.org/wiki/Titan_(moon)http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-36http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-36http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-36http://en.wikipedia.org/wiki/Anti-greenhouse_effecthttp://en.wikipedia.org/wiki/Atmosphere_of_Plutohttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-37http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-37http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-37http://en.wikipedia.org/wiki/Runaway_greenhouse_effecthttp://en.wikipedia.org/wiki/Positive_feedbackhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Kasting_1991-39http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Kasting_1991-39http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Kasting_1991-39http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-40http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-40http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-40http://en.wikipedia.org/wiki/Industrial_Revolutionhttp://en.wikipedia.org/wiki/Fossil_fuelshttp://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmospherehttp://en.wikipedia.org/wiki/Parts_per_millionhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-blasing_ghg_concentrations-5http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-blasing_ghg_concentrations-5http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-blasing_ghg_concentrations-5http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-blasing_ghg_concentrations-5http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-blasing_ghg_concentrations-5http://en.wikipedia.org/wiki/Parts_per_millionhttp://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmospherehttp://en.wikipedia.org/wiki/Fossil_fuelshttp://en.wikipedia.org/wiki/Industrial_Revolutionhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-40http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Kasting_1991-39http://en.wikipedia.org/wiki/Positive_feedbackhttp://en.wikipedia.org/wiki/Runaway_greenhouse_effecthttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-37http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-37http://en.wikipedia.org/wiki/Atmosphere_of_Plutohttp://en.wikipedia.org/wiki/Anti-greenhouse_effecthttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-36http://en.wikipedia.org/wiki/Titan_(moon)http://en.wikipedia.org/wiki/Venus#Atmosphere_and_climatehttp://en.wikipedia.org/wiki/Marshttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Schroeder-4http://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-Schroeder-4http://en.wikipedia.org/wiki/Convectionhttp://en.wikipedia.org/wiki/Greenhouse_effect#cite_note-wood1909-3http://en.wikipedia.org/wiki/Halitehttp://en.wikipedia.org/wiki/Robert_W._Wood


21/64

uptake of a large portion of the emissions by various natural "sinks" involved in

thecarbon cycle.[7][8]Anthropogenic carbon dioxide (CO2) emissions (i.e.,

emissions produced by human activities) come fromcombustionofcarbon-based

fuels,principallywood,coal,oil,andnatural gas.[9]

Under ongoing greenhouse gas

emissions, available Earth System Models project that the Earth's surface

temperature could exceed historical analogs as early as 2047 affecting most

ecosystems on Earth and the livelihoods of over 3 billion people

worldwide.[10]Greenhouse gasses also trigger ocean bio-geochemical changes with

broad ramifications in marine systems.[11]

In theSolar System,the atmospheres ofVenus,Mars,andTitan also contain gases

that cause a greenhouse effect, though Titan's atmosphere has ananti-greenhouse

effect which reduces the warming.

Contents

[hide]

1 Gases in Earth's atmosphereo 1.1 Greenhouse gaseso 1.2 Non-greenhouse gaseso 1.3 Indirect radiative effectso 1.4 Contribution of clouds to Earth's greenhouse effect

2 Impacts on the overall greenhouse effecto 2.1 Proportion of direct effects at a given momento 2.2 Atmospheric lifetimeo 2.3 Radiative forcingo 2.4 Global warming potential

3 Natural and anthropogenic sources
http://en.wikipedia.org/wiki/Carbon_cyclehttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-cdiac-7http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-cdiac-7http://en.wikipedia.org/wiki/Human_impact_on_the_environmenthttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Carbon-based_fuelhttp://en.wikipedia.org/wiki/Carbon-based_fuelhttp://en.wikipedia.org/wiki/Woodhttp://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/Oilhttp://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-9http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-9http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-10http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-10http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-10http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-11http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-11http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-11http://en.wikipedia.org/wiki/Solar_Systemhttp://en.wikipedia.org/wiki/Atmosphere_of_Venushttp://en.wikipedia.org/wiki/Atmosphere_of_Marshttp://en.wikipedia.org/wiki/Atmosphere_of_Titanhttp://en.wikipedia.org/wiki/Anti-greenhouse_effecthttp://en.wikipedia.org/wiki/Anti-greenhouse_effecthttp://en.wikipedia.org/wiki/Greenhouse_gashttp://en.wikipedia.org/wiki/Greenhouse_gas#Gases_in_Earth.27s_atmospherehttp://en.wikipedia.org/wiki/Greenhouse_gas#Greenhouse_gaseshttp://en.wikipedia.org/wiki/Greenhouse_gas#Non-greenhouse_gaseshttp://en.wikipedia.org/wiki/Greenhouse_gas#Indirect_radiative_effectshttp://en.wikipedia.org/wiki/Greenhouse_gas#Contribution_of_clouds_to_Earth.27s_greenhouse_effecthttp://en.wikipedia.org/wiki/Greenhouse_gas#Impacts_on_the_overall_greenhouse_effecthttp://en.wikipedia.org/wiki/Greenhouse_gas#Proportion_of_direct_effects_at_a_given_momenthttp://en.wikipedia.org/wiki/Greenhouse_gas#Atmospheric_lifetimehttp://en.wikipedia.org/wiki/Greenhouse_gas#Radiative_forcinghttp://en.wikipedia.org/wiki/Greenhouse_gas#Global_warming_potentialhttp://en.wikipedia.org/wiki/Greenhouse_gas#Natural_and_anthropogenic_sourceshttp://en.wikipedia.org/wiki/Greenhouse_gas#Natural_and_anthropogenic_sourceshttp://en.wikipedia.org/wiki/Greenhouse_gas#Global_warming_potentialhttp://en.wikipedia.org/wiki/Greenhouse_gas#Radiative_forcinghttp://en.wikipedia.org/wiki/Greenhouse_gas#Atmospheric_lifetimehttp://en.wikipedia.org/wiki/Greenhouse_gas#Proportion_of_direct_effects_at_a_given_momenthttp://en.wikipedia.org/wiki/Greenhouse_gas#Impacts_on_the_overall_greenhouse_effecthttp://en.wikipedia.org/wiki/Greenhouse_gas#Contribution_of_clouds_to_Earth.27s_greenhouse_effecthttp://en.wikipedia.org/wiki/Greenhouse_gas#Indirect_radiative_effectshttp://en.wikipedia.org/wiki/Greenhouse_gas#Non-greenhouse_gaseshttp://en.wikipedia.org/wiki/Greenhouse_gas#Greenhouse_gaseshttp://en.wikipedia.org/wiki/Greenhouse_gas#Gases_in_Earth.27s_atmospherehttp://en.wikipedia.org/wiki/Greenhouse_gashttp://en.wikipedia.org/wiki/Anti-greenhouse_effecthttp://en.wikipedia.org/wiki/Anti-greenhouse_effecthttp://en.wikipedia.org/wiki/Atmosphere_of_Titanhttp://en.wikipedia.org/wiki/Atmosphere_of_Marshttp://en.wikipedia.org/wiki/Atmosphere_of_Venushttp://en.wikipedia.org/wiki/Solar_Systemhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-11http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-10http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-9http://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Oilhttp://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/Woodhttp://en.wikipedia.org/wiki/Carbon-based_fuelhttp://en.wikipedia.org/wiki/Carbon-based_fuelhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Human_impact_on_the_environmenthttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-cdiac-7http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-cdiac-7http://en.wikipedia.org/wiki/Carbon_cycle


22/64

o 3.1 Ice coreso 3.2 Changes since the Industrial Revolution

4 Anthropogenic greenhouse gaseso 4.1 Sectors

5 Role of water vapor 6 Direct greenhouse gas emissions

o 6.1 Regional and national attribution of emissionso 6.2 Greenhouse gas intensity and land-use changeo 6.3 Cumulative and historical emissionso 6.4 Changes since a particular base yearo 6.5 Annual emissionso 6.6 Top emitters

6.6.1 Annual 6.6.2 Cumulative

o 6.7 Embedded emissionso 6.8 Effect of policyo 6.9 Projectionso 6.10 Relative CO2emission from various fuels

7 Life-cycle greenhouse-gas emissions of energy sources 8 Removal from the atmosphere ("sinks")

o 8.1 Natural processeso 8.2 Negative emissions

9 History of scientific research 10 See also 11 Notes and references
http://en.wikipedia.org/wiki/Greenhouse_gas#Ice_coreshttp://en.wikipedia.org/wiki/Greenhouse_gas#Changes_since_the_Industrial_Revolutionhttp://en.wikipedia.org/wiki/Greenhouse_gas#Anthropogenic_greenhouse_gaseshttp://en.wikipedia.org/wiki/Greenhouse_gas#Sectorshttp://en.wikipedia.org/wiki/Greenhouse_gas#Role_of_water_vaporhttp://en.wikipedia.org/wiki/Greenhouse_gas#Direct_greenhouse_gas_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Regional_and_national_attribution_of_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Greenhouse_gas_intensity_and_land-use_changehttp://en.wikipedia.org/wiki/Greenhouse_gas#Cumulative_and_historical_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Changes_since_a_particular_base_yearhttp://en.wikipedia.org/wiki/Greenhouse_gas#Annual_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Top_emittershttp://en.wikipedia.org/wiki/Greenhouse_gas#Annualhttp://en.wikipedia.org/wiki/Greenhouse_gas#Cumulativehttp://en.wikipedia.org/wiki/Greenhouse_gas#Embedded_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Effect_of_policyhttp://en.wikipedia.org/wiki/Greenhouse_gas#Projectionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Relative_CO2_emission_from_various_fuelshttp://en.wikipedia.org/wiki/Greenhouse_gas#Relative_CO2_emission_from_various_fuelshttp://en.wikipedia.org/wiki/Greenhouse_gas#Relative_CO2_emission_from_various_fuelshttp://en.wikipedia.org/wiki/Greenhouse_gas#Life-cycle_greenhouse-gas_emissions_of_energy_sourceshttp://en.wikipedia.org/wiki/Greenhouse_gas#Removal_from_the_atmosphere_.28.22sinks.22.29http://en.wikipedia.org/wiki/Greenhouse_gas#Natural_processeshttp://en.wikipedia.org/wiki/Greenhouse_gas#Negative_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#History_of_scientific_researchhttp://en.wikipedia.org/wiki/Greenhouse_gas#See_alsohttp://en.wikipedia.org/wiki/Greenhouse_gas#Notes_and_referenceshttp://en.wikipedia.org/wiki/Greenhouse_gas#Notes_and_referenceshttp://en.wikipedia.org/wiki/Greenhouse_gas#See_alsohttp://en.wikipedia.org/wiki/Greenhouse_gas#History_of_scientific_researchhttp://en.wikipedia.org/wiki/Greenhouse_gas#Negative_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Natural_processeshttp://en.wikipedia.org/wiki/Greenhouse_gas#Removal_from_the_atmosphere_.28.22sinks.22.29http://en.wikipedia.org/wiki/Greenhouse_gas#Life-cycle_greenhouse-gas_emissions_of_energy_sourceshttp://en.wikipedia.org/wiki/Greenhouse_gas#Relative_CO2_emission_from_various_fuelshttp://en.wikipedia.org/wiki/Greenhouse_gas#Projectionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Effect_of_policyhttp://en.wikipedia.org/wiki/Greenhouse_gas#Embedded_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Cumulativehttp://en.wikipedia.org/wiki/Greenhouse_gas#Annualhttp://en.wikipedia.org/wiki/Greenhouse_gas#Top_emittershttp://en.wikipedia.org/wiki/Greenhouse_gas#Annual_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Changes_since_a_particular_base_yearhttp://en.wikipedia.org/wiki/Greenhouse_gas#Cumulative_and_historical_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Greenhouse_gas_intensity_and_land-use_changehttp://en.wikipedia.org/wiki/Greenhouse_gas#Regional_and_national_attribution_of_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Direct_greenhouse_gas_emissionshttp://en.wikipedia.org/wiki/Greenhouse_gas#Role_of_water_vaporhttp://en.wikipedia.org/wiki/Greenhouse_gas#Sectorshttp://en.wikipedia.org/wiki/Greenhouse_gas#Anthropogenic_greenhouse_gaseshttp://en.wikipedia.org/wiki/Greenhouse_gas#Changes_since_the_Industrial_Revolutionhttp://en.wikipedia.org/wiki/Greenhouse_gas#Ice_cores


23/64

12 Bibliography 13 External links

Gases in Earth's atmosphere[edit]

Main articles:Greenhouse effect,Global warming,andCarbon dioxide in Earth's

atmosphere

Greenhouse gases[edit]

Atmospheric absorption and scattering at differentwavelengths ofelectromagnetic

waves.The largest absorption band ofcarbon dioxide is in theinfrared.

Greenhouse gases are those that can absorb and emitinfrared radiation,[1]but not

radiation in or near the visible spectrum. In order, the most abundant greenhouse

gases in Earth's atmosphere are:

Water vapor (H2O)

Carbon dioxide (CO2) Methane (CH

4)
http://en.wikipedia.org/wiki/Greenhouse_gas#Bibliographyhttp://en.wikipedia.org/wiki/Greenhouse_gas#External_linkshttp://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=1http://en.wikipedia.org/wiki/Greenhouse_effecthttp://en.wikipedia.org/wiki/Global_warminghttp://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmospherehttp://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmospherehttp://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=2http://en.wikipedia.org/wiki/Wavelengthhttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Thermal_infraredhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-IPCC_AR4-SYR-1http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-IPCC_AR4-SYR-1http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-IPCC_AR4-SYR-1http://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/File:Atmospheric_Transmission.pnghttp://en.wikipedia.org/wiki/File:Atmospheric_Transmission.pnghttp://en.wikipedia.org/wiki/File:Atmospheric_Transmission.pnghttp://en.wikipedia.org/wiki/File:Atmospheric_Transmission.pnghttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-IPCC_AR4-SYR-1http://en.wikipedia.org/wiki/Thermal_infraredhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Wavelengthhttp://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=2http://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmospherehttp://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmospherehttp://en.wikipedia.org/wiki/Global_warminghttp://en.wikipedia.org/wiki/Greenhouse_effecthttp://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=1http://en.wikipedia.org/wiki/Greenhouse_gas#External_linkshttp://en.wikipedia.org/wiki/Greenhouse_gas#Bibliography


24/64

Nitrous oxide (N2O)

Ozone (O3)

CFCsAtmospheric concentrations of greenhouse gases are determined by the balance

between sources (emissions of the gas from human activities and natural systems)

and sinks (the removal of the gas from the atmosphere by conversion to a different

chemical compound).[12]The proportion of an emission remaining in the

atmosphere after a specified time is the "Airborne fraction"(AF). More precisely,the annual AF is the ratio of the atmospheric increase in a given year to that year's

total emissions. For CO2the AF over the last 50 years (19562006) has been

increasing at 0.25 0.21%/year.[13]

Non-greenhouse gases[edit]

Although contributing to many other physical and chemical reactions, the major

atmospheric constituents,nitrogen (N

2),oxygen (O

2), andargon (Ar), are not greenhouse gases. This is becausemolecules containing

two atoms of the same element such as N

2 and O

2andmonatomic molecules such as argon (Ar) have no net change in theirdipole

moment when they vibrate and hence are almost totally unaffected byinfrared

radiation. Although molecules containing two atoms of different elements such

ascarbon monoxide (CO) orhydrogen chloride (HCl) absorb IR, these molecules

are short-lived in the atmosphere owing to their reactivity and solubility. Because
http://en.wikipedia.org/wiki/Nitrous_oxidehttp://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Chlorofluorocarbonhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-IPCC_WG1_AR4_Ch7-12http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-IPCC_WG1_AR4_Ch7-12http://en.wikipedia.org/wiki/Airborne_fractionhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-Canadell2007-13http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-Canadell2007-13http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-Canadell2007-13http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=3http://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Argonhttp://en.wikipedia.org/wiki/Diatomic_moleculehttp://en.wikipedia.org/wiki/Diatomic_moleculehttp://en.wikipedia.org/wiki/Monatomichttp://en.wikipedia.org/wiki/Molecular_dipole_momenthttp://en.wikipedia.org/wiki/Molecular_dipole_momenthttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Carbon_monoxidehttp://en.wikipedia.org/wiki/Hydrogen_chloridehttp://en.wikipedia.org/wiki/Hydrogen_chloridehttp://en.wikipedia.org/wiki/Carbon_monoxidehttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Molecular_dipole_momenthttp://en.wikipedia.org/wiki/Molecular_dipole_momenthttp://en.wikipedia.org/wiki/Monatomichttp://en.wikipedia.org/wiki/Diatomic_moleculehttp://en.wikipedia.org/wiki/Diatomic_moleculehttp://en.wikipedia.org/wiki/Argonhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=3http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-Canadell2007-13http://en.wikipedia.org/wiki/Airborne_fractionhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-IPCC_WG1_AR4_Ch7-12http://en.wikipedia.org/wiki/Chlorofluorocarbonhttp://en.wikipedia.org/wiki/Ozonehttp://en.wikipedia.org/wiki/Nitrous_oxide


25/64

they do not contribute significantly to the greenhouse effect, they are usually

omitted when discussing greenhouse gases.

Indirect radiative effects[edit]

The false colors in this image represent levels of carbon monoxide in the lower

atmosphere, ranging from about 390 parts per billion (dark brown pixels), to 220

parts per billion (red pixels), to 50 parts per billion (blue pixels).[14]

Some gases have indirect radiative effects (whether or not they are a greenhouse

gas themselves). This happens in two main ways. One way is that when they break

down in the atmosphere they produce another greenhouse gas. For example

methane and carbon monoxide (CO) are oxidized to give carbon dioxide (and

methane oxidation also produces water vapor; that will be considered below).

Oxidation of CO to CO2directly produces an unambiguous increase in radiative

forcing although the reason is subtle. The peak of the thermal IR emission from the

Earth's surface is very close to a strong vibrational absorption band of

CO2(667 cm1). On the other hand, the single CO vibrational band only absorbs IR

at much higher frequencies (2145 cm1), where the ~300 K thermal emission of the

surface is at least a factor of ten lower. On the other hand, oxidation of methane to

CO2which requires reactions with the OH radical, produces an instantaneous
http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=4http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-14http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-14http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-14http://en.wikipedia.org/wiki/File:Mopitt_first_year_carbon_monoxide.jpghttp://en.wikipedia.org/wiki/File:Mopitt_first_year_carbon_monoxide.jpghttp://en.wikipedia.org/wiki/File:Mopitt_first_year_carbon_monoxide.jpghttp://en.wikipedia.org/wiki/File:Mopitt_first_year_carbon_monoxide.jpghttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-14http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=4


26/64

reduction, since CO2is a weaker greenhouse gas than methane; but it has a longer

lifetime. As described below this is not the whole story, since the oxidations of CO

andCH

4 are intertwined by both consuming OH radicals. In any case, the calculation of

the total radiative effect needs to include both the direct and indirect forcing.

A second type of indirect effect happens when chemical reactions in the

atmosphere involving these gases change the concentrations of greenhouse gases.

For example, the destruction ofnon-methane volatile organic

compounds (NMVOC) in the atmosphere can produce ozone. The size of the

indirect effect can depend strongly on where and when the gas is emitted.[15]

Methane has a number of indirect effects in addition to forming CO 2. Firstly, the

main chemical which destroys methane in the atmosphere is thehydroxyl

radical (OH). Methane reacts with OH and so more methane means that the

concentration of OH goes down. Effectively, methane increases its own

atmospheric lifetime and therefore its overall radiative effect. The second effect is

that the oxidation of methane can produce ozone. Thirdly, as well as makingCO2the oxidation of methane produces water; this is a major source of water vapor

in thestratosphere which is otherwise very dry. CO and NMVOC also produce

CO2when they are oxidized. They remove OH from the atmosphere and this leads

to higher concentrations of methane. The surprising effect of this is that the global

warming potential of CO is three times that of CO2.[16]The same process that

converts NMVOC to carbon dioxide can also lead to the formation of tropospheric

ozone. Halocarbons have an indirect effect because they destroy stratospheric

ozone. Finallyhydrogen can lead to ozone production and CH

4 increases as well as producing water vapor in the stratosphere.[15]

Contribution of clouds to Earth's greenhouse effect[edit]
http://en.wikipedia.org/wiki/NMVOChttp://en.wikipedia.org/wiki/NMVOChttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-forsteretal-15http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-forsteretal-15http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-forsteretal-15http://en.wikipedia.org/wiki/Hydroxyl_radicalhttp://en.wikipedia.org/wiki/Hydroxyl_radicalhttp://en.wikipedia.org/wiki/Stratospherehttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-maccartyetal-16http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-maccartyetal-16http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-maccartyetal-16http://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-forsteretal-15http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-forsteretal-15http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-forsteretal-15http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=5http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=5http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-forsteretal-15http://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-maccartyetal-16http://en.wikipedia.org/wiki/Stratospherehttp://en.wikipedia.org/wiki/Hydroxyl_radicalhttp://en.wikipedia.org/wiki/Hydroxyl_radicalhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-forsteretal-15http://en.wikipedia.org/wiki/NMVOChttp://en.wikipedia.org/wiki/NMVOC


27/64

The major non-gas contributor to the Earth's greenhouse effect,clouds,also absorb

and emit infrared radiation and thus have an effect on radiative properties of the

greenhouse gases. Clouds are water droplets orice crystals suspended in the

atmosphere.[17][18]

Impacts on the overall greenhouse effect[edit]

Schmidt et al.(2010)[19]analysed how individual components of the atmosphere

contribute to the total greenhouse effect. They estimated that water vapor accounts

for about 50% of the Earth's greenhouse effect, with clouds contributing 25%,

carbon dioxide 20%, and the minor greenhouse gases andaerosols accounting for

the remaining 5%. In the study, the reference model atmosphere is for 1980

conditions. Image credit:NASA.[20]

The contribution of each gas to the greenhouse effect is affected by the

characteristics of that gas, its abundance, and any indirect effects it may cause. For

example, the direct radiative effect of a mass of methane is about 72 times stronger

than the same mass of carbon dioxide over a 20-year time frame[21]but it is present

in much smaller concentrations so that its total direct radiative effect is smaller, in

part due to its shorter atmospheric lifetime. On the other hand, in addition to its

direct radiative impact, methane has a large, indirect radiative effect because it

contributes to ozone formation. Shindell et al.(2005)[22]argue that the contribution

to climate change from methane is at least double previous estimates as a result of

this effect.[23]

When ranked by their direct contribution to the greenhouse effect, the most

important are:[17]
http://en.wikipedia.org/wiki/Cloud_forcinghttp://en.wikipedia.org/wiki/Ice_crystalhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=6http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-19http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-19http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-19http://en.wikipedia.org/wiki/Aerosolhttp://en.wikipedia.org/wiki/NASAhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-20http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-20http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-20http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-TableOfWarmingPotentials-21http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-TableOfWarmingPotentials-21http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-22http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-22http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-23http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-23http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-23http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/File:Attribution_of_individual_atmospheric_component_contributions_to_the_terrestrial_greenhouse_effect,_separated_into_feedback_and_forcing_categories_(NASA).pnghttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-23http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-22http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-TableOfWarmingPotentials-21http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-20http://en.wikipedia.org/wiki/NASAhttp://en.wikipedia.org/wiki/Aerosolhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-19http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=6http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Ice_crystalhttp://en.wikipedia.org/wiki/Cloud_forcing


28/64

Compound Formula Contribution

(%)

Water vapor and clouds H

2O3672%

Carbon dioxide CO2 926%

MethaneCH

4

49%

OzoneO

337%

In addition to the main greenhouse gases listed above, other greenhouse gases

includesulfur hexafluoride,hydrofluorocarbons andperfluorocarbons (seeIPCC

list of greenhouse gases). Some greenhouse gases are not often listed. Forexample,nitrogen trifluoridehas a highglobal warming potential (GWP) but is

only present in very small quantities.[24]

Proportion of direct effects at a given moment[edit]

It is not possible to state that a certain gas causes an exact percentage of the

greenhouse effect. This is because some of the gases absorb and emit radiation at

the same frequencies as others, so that the total greenhouse effect is not simply thesum of the influence of each gas. The higher ends of the ranges quoted are for each

gas alone; the lower ends account for overlaps with the other gases.[17][18]In

addition, some gases such as methane are known to have large indirect effects that

are still being quantified.[25]
http://en.wikipedia.org/wiki/Sulfur_hexafluoridehttp://en.wikipedia.org/wiki/Hydrofluorocarbonhttp://en.wikipedia.org/wiki/Perfluorocarbonhttp://en.wikipedia.org/wiki/IPCC_list_of_greenhouse_gaseshttp://en.wikipedia.org/wiki/IPCC_list_of_greenhouse_gaseshttp://en.wikipedia.org/wiki/Nitrogen_trifluoridehttp://en.wikipedia.org/wiki/Global_warming_potentialhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-NF3-24http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-NF3-24http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-NF3-24http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=7http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-25http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-25http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-25http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-25http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-kiehl197-17http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=7http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-NF3-24http://en.wikipedia.org/wiki/Global_warming_potentialhttp://en.wikipedia.org/wiki/Nitrogen_trifluoridehttp://en.wikipedia.org/wiki/IPCC_list_of_greenhouse_gaseshttp://en.wikipedia.org/wiki/IPCC_list_of_greenhouse_gaseshttp://en.wikipedia.org/wiki/Perfluorocarbonhttp://en.wikipedia.org/wiki/Hydrofluorocarbonhttp://en.wikipedia.org/wiki/Sulfur_hexafluoride


29/64

Atmospheric lifetime[edit]

Aside fromwater vapor,which has a residence time of about nine days,[26]major

greenhouse gases are well-mixed, and take many years to leave the

atmosphere.[27]Although it is not easy to know with precision how long it takes

greenhouse gases to leave the atmosphere, there are estimates for the principal

greenhouse gases. Jacob (1999)[28]defines the lifetime of an

atmosphericspecies X in aone-box model as the average time that a molecule of X

remains in the box. Mathematically can be defined as the ratio of the mass (in

kg) of X in the box to its removal rate, which is the sum of the flow of X out of the

box ( ), chemical loss of X ( ), anddeposition of X ( ) (all in

kg/s): .[28]If one stopped pouring any of this gas into the box,

then after a time , its concentration would be about halved.

The atmospheric lifetime of a species therefore measures the time required to

restore equilibrium following a sudden increase or decrease in its concentration in

the atmosphere. Individual atoms or molecules may be lost or deposited to sinks

such as the soil, the oceans and other waters, or vegetation and other biological

systems, reducing the excess to background concentrations. The average time

taken to achieve this is themean lifetime.

Carbon dioxide has a variable atmospheric lifetime, and cannot be specified

precisely.[29]The atmospheric lifetime of CO2 is estimated of the order of 3095

years.[30]This figure accounts for CO2molecules being removed from the

atmosphere by mixing into the ocean, photosynthesis, and other processes.

However, this excludes the balancing fluxes of CO2into the atmosphere from the

geological reservoirs, which have slower characteristic rates.[31]While more than

half of the CO2emitted is removed from the atmosphere within a century, some
http://en.wikipedia.org/w/index.php?title=Greenhouse_gas&action=edit&section=8http://en.wikipedia.org/wiki/Water_vaporhttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-26http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-26http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-26http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-betts-27http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-betts-27http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-betts-27http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-JacobDJ1999-28http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-JacobDJ1999-28http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-JacobDJ1999-28http://en.wikipedia.org/wiki/Chemical_specieshttp://en.wikipedia.org/wiki/Climate_model#Box_modelshttp://en.wikipedia.org/wiki/Deposition_(chemistry)http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-JacobDJ1999-28http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-JacobDJ1999-28http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-JacobDJ1999-28http://en.wikipedia.org/wiki/Mean_lifetimehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-29http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-29http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-29http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-JacobsonMZ2005-30http://en.wikipedia.org/wiki/Greenhouse_gas#cite_note-JacobsonMZ2005-30h

green house effects

Documents