By : Reeti ChoudharySection : C

contents

1.Climate v/s Weather2.What is climatic change?3.Causes for climatic change.

• Global warming• Greenhouse effect• Ozone layer depletion• Human activities

4.Impacts of climatic changes5.References

CLIMATE WEATHER

•Describes the average conditions expected at a specific place at a given time.

• Describes the atmospheric conditions at a specific place at a specific point in time. 

•Measured over a long period. • Measured for short term.

•Climate may include precipitation, temperature, humidity, sunshine, wind velocity, phenomena such as fog, frost, and hail storms over a long period of time.

• Weather includes sunshine, rain, cloud cover, winds, hail, snow, sleet, freezing rain, flooding, blizzards, ice storms, thunderstorms, steady rains from a cold front or warm front, excessive heat, heat waves and more.

• The study of climate is called Climatology.

• The study of weather is called Meteorology.

Climate v/s weather

What is climatic change ? Climate change is a change in the statistical

distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years).

It is a change which is attributed directly or indirectly to Human Activity that alters the composition of the Global Atmosphere and which is in addition to Natural climate variability observed over comparative time periods.

It is often referred to as GLOBAL WARMING.

What causes earth’s climate to change ?

The major causes for Earth’s climatic change are:

Global Warming Greenhouse Effect Ozone Layer Depletion Human Activities

L

GLOBAL WARMING

Causes Natural causes:•Volcanic Erruptions• Ocean currents• Earth’s orbital changes

Man made causes:• Burning of fossil fuels• Excessive farming• Deforestation• Industrial emissions

Volcanic eruptions

A volcanic eruption occurs when hot materials are thrown out of a volcano. Lava, rocks, dust, ash and gas compounds are some of the materials.These eruptions leads to increase in the temperature of the earth and hence causing global warming.

Ocean Currents

Ocean currents flow for great distances, and together, create the global conveyor belt which plays a dominant role in determining the climate of many of the Earth’s regions. More specifically, ocean currents influence the temperature of the regions through which they travel. For example, warm currents traveling along more temperate coasts increase the temperature of the area by warming the sea breezes that blow over them.

Orbital variations• Slight variations in Earth's orbit lead to changes in the

seasonal distribution of sunlight reaching the Earth's surface and how it is distributed across the globe. There is very little change to the area-averaged annually averaged sunshine; but there can be strong changes in the geographical and seasonal distribution.

The Greenhouse Effect

The greenhouse effect is a natural process that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.

Gas in the atmosphere, such a water, carbon dioxide, methane, CFCs and nitrous oxide, absorb infrared light and would otherwise escape to space, radiating it back towards the planet’s surface.

These gases are called ‘ greenhouse gases’ and they have a critical role in determining the temperature of the Earth’s surface and the living conditions on the planet and hence changing the climate of a place.

KYOTO PROTOCOL

Depletion of Ozone Layer• Chlorofluorocarbons (CFCs) and other halogenated ozone

depleting substances (ODS) are mainly responsible for man-made chemical ozone depletion.

• This thinning of the ozone layer makes the life on earth more prone to UV radiations that may cause several skin diseases as well as climatic chnages.

Human activities

DEFORESTATION BURNING OF FOSSIL FUELS

INDUSTRIAL EMISSIONS

AND MANY

MORE...

ImpactsOf

ClimaticChange

Rise In

Temperature

of theEarth

Melting polar icecaps will raise ocean levels; the Arctic Ocean could be ice free in summer by 2050.

Global sea levels could rise by more than 20 feet, devastating

coastal areas worldwide.

Frequent storms, droughts, floods, submergence of

islands

Scientists have warned that a warmer world will mean more storms, floods, droughts, and snowfalls.

Islands in danger of being submerged, from the Pacific to the Caribbean are panicky. The lives of million people will be affected by these negotiations.

More than a million species worldwide could be extinct by 2050.

References www.google.com https://en.wikipedia.org/ climate.nasa.gov/