Climate ChangeClimate ChangeBiology ABiology A

In 2005, an In 2005, an ice core ice core

showed that showed that CO2 levels CO2 levels

in the in the troposphere troposphere

are the are the highest they highest they have been have been in 650,000 in 650,000

years.years.

CLIMATE CHANGE VS. GLOBAL CLIMATE CHANGE VS. GLOBAL WARMINGWARMING

In recent years, experts have changed In recent years, experts have changed their discussions from the topic of “global their discussions from the topic of “global warming” to “climate change”warming” to “climate change”

This is because This is because global warming suggests a global warming suggests a constant increase in temperatureconstant increase in temperature, while , while climate change includes all major changes climate change includes all major changes in weather patterns.in weather patterns.

Climate change explains increases in Climate change explains increases in hurricanes and flooding ALONG WITH hurricanes and flooding ALONG WITH major snow storms and below normal major snow storms and below normal temperatures.temperatures.

PAST CLIMATE AND THE PAST CLIMATE AND THE GREENHOUSE EFFECTGREENHOUSE EFFECT

Over the past 900,000 years, the planet has Over the past 900,000 years, the planet has experienced prolonged periods of global cooling and experienced prolonged periods of global cooling and global warming.global warming.

Major Greenhouse Major Greenhouse GasesGases

A greenhouse gas is A greenhouse gas is any gas any gas that traps heat within the that traps heat within the earth’s atmosphereearth’s atmosphere, rather , rather than allowing it to escape as than allowing it to escape as it otherwise would.it otherwise would.

Increases in average Increases in average concentrations of 3 concentrations of 3 greenhouse gases between greenhouse gases between 1860 and 2004, mostly due 1860 and 2004, mostly due to fossil fuel burning, to fossil fuel burning, deforestation, and deforestation, and agriculture.agriculture.

CLIMATE CHANGE AND CLIMATE CHANGE AND HUMAN ACTIVITIESHUMAN ACTIVITIES

Evidence that the planet is warming, mostly Evidence that the planet is warming, mostly because of human actions:because of human actions: The 20The 20thth century was the hottest century in the past century was the hottest century in the past

1000 years.1000 years. Since 1900, the earth’s average temperature has Since 1900, the earth’s average temperature has

risen 0.6 Crisen 0.6 C°° Over the past 50 years, Arctic temperatures have Over the past 50 years, Arctic temperatures have

risen almost 2x as fast as those in the rest of the risen almost 2x as fast as those in the rest of the world.world.

Glaciers and floating sea ice are melting and Glaciers and floating sea ice are melting and shrinking at increasing rates.shrinking at increasing rates.

During the last century, the world’s sea level rose During the last century, the world’s sea level rose by 10-20 cmby 10-20 cm

EFFECTS OF CLIMATE EFFECTS OF CLIMATE CHANGECHANGE

Between 1979 and 2005, average Arctic sea ice Between 1979 and 2005, average Arctic sea ice dropped 20% (as shown in blue hues above).dropped 20% (as shown in blue hues above).

EFFECTS OF CLIMATE EFFECTS OF CLIMATE CHANGECHANGE

Rising Sea Rising Sea Levels:Levels:

If seas levels If seas levels rise by 9-88cm rise by 9-88cm during this during this century, most century, most of the Maldives of the Maldives islands and islands and their coral their coral reefs will be reefs will be flooded.flooded.

EFFECTS OF CLIMATE EFFECTS OF CLIMATE CHANGECHANGE

In a warmer world, agricultural In a warmer world, agricultural productivity will be alteredproductivity will be altered

Crop and fish production in some areas Crop and fish production in some areas could be reduced by rising sea levels could be reduced by rising sea levels

Global warming will increase deaths Global warming will increase deaths from:from: Heat and disruption of food supplyHeat and disruption of food supply Spread of tropical diseases to temperate Spread of tropical diseases to temperate

regionsregions

Global warming may harm human health November 16, 1998Climatic changes related to global warming could foster dangerous outbreaks of cholera, dengue fever and malaria, …

http://www.cnn.com/TECH/science/9811/16/climate.health.enn/index.html

Study: Global warming spurs migrations Thursday, January 2, 2003

Rising global temperatures that have lured plants into early bloom and birds to nest earlier in the spring are altering the ranges and behavior of hundreds of plant and animal species worldwide, two studies conclude. http://www.cnn.com/2003/TECH/science/01/02/climate.migrations.ap/index.html

Report: Coral bleaching hits record level May 19, 1999 Global warming has been linked to an unprecedented episode of coral bleaching in 1998, …

http://www.cnn.com/NATURE/9905/19/coral.bleaching.enn/index.html

Vicious cycle: Global warming feeds fire potentialNovember 2, 2000 Global warming may greatly accelerate the fire cycle in the desert ecosystem of North America, according to a study published today in the journal Nature. Elevated carbon dioxide levels, the result of increased fossil fuel burning, can alter the delicate balance of grasses in desert areas, the report notes. This finding may have major implications for the biodiversity and health of desert ecosystems in the western United States. http://www.cnn.com/2000/NATURE/11/02/global.warming.enn/index.html

Top Greenhouse EmittersTop Greenhouse Emitters

19.1 % - United States19.1 % - United States 9.9% - China9.9% - China 5.1% - India5.1% - India 4.3% - Brazil4.3% - Brazil 3.8 % - Germany3.8 % - Germany 3.7% - Japan3.7% - Japan 2.4% - United Kingdom2.4% - United Kingdom 1.9% - Indonesia1.9% - Indonesia 1.7% - Italy1.7% - Italy

Reducing CO2 Emissions

• Drive a fuel-efficient car, walk, bike, carpool, and use mass transit

• Use energy-efficient windows

• Use energy-efficient appliances and lights

• Heavily insulate your house and seal all drafts

• Reduce garbage by recycling and reuse

• Insulate your hot water heater

• Use compact fluorescent bulbs

• Plant trees to shade your house during summer

• Set water heater no higher than 49°C (120°F)

• Wash laundry in warm or cold water

• Use low-flow shower head

• Buy products from companies that are trying to reduce their impact on climate

• Demand that the government make climate change an urgent priority

What Can You Do?