CHAPTER 19. Global Change

Transcription

1 CHAPTER 19 Global Change

2 WALKING ON THIN ICE Polar bears play important role in North Pole ecosystem Food seals Important as food and fur for clothing source for indigenous people Problem temperatures in Arctic have risen faster than in other parts of the world Causing polar ice cap to melt Natural shrinking and expansion occurs Polar bears are losing habitat due to polar ice melting What happens if we lose polar bears? 2008 US classified polar bears as threatened species 2009 Canada, Greenland, Norway, Russia and US agreed effect of global warming on ice cap posed greatest threat to polar bears

3 GLOBAL CHANGE Global change any chemical, biological or physical property change of the planet. Global climate change changes in the climate of the Earth Can be natural or anthropogenic Global warming one aspect of climate change The warming of the oceans, land masses and atmosphere of the Earth

4 THE GREENHOUSE EFFECT

5 THE GREENHOUSE EFFECT Greenhouse gases gases that absorb infrared radiation Include: Make up small percentage of atmosphere IMPORTANT!

6 MAJOR GREENHOUSE GASES

7 NATURAL GREENHOUSE GASES Volcanic eruptions mainly carbon dioxide Also releases ash Methane from decomposition Nitrous oxide from denitrification Water vapor evapotranspiration or evaporation

8 ANTHROPOGENIC CAUSES OF GREENHOUSE GASES Burning of fossil fuels Agricultural practices Deforestation Landfills Industrial production- CFC s are an example

9 ANTHROPOGENIC SOURCES OF GREENHOUSE GASES

10 ANTHROPOGENIC SOURCES OF GREENHOUSE GASES IN US

11 IPCC 1988 Intergovernmetnal Panel on Climate Change (IPCC) formed Formed by UN and World Meteorological Organization More than 3000 scientists from around world Goal to understand the details of:

12 INCREASING CO 2 CONCENTRATIONS David Keeling began measuring CO 2 in 1958.

13 EMISSIONS FROM THE DEVELOPED AND DEVELOPING WORLD

14 GLOBAL TEMPERATURES SINCE 1880 Since 1880 temperatures have increased 0.8 C.

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16 TEMPERATURES AND GREENHOUSE GAS CONCENTRATIONS IN PAST 400,000 YEARS No one was around thousands of years ago to measure temperatures so we use other indirect measurements Including: Changes in species compositions Chemical analyses of ice

17 HISTORIC CO 2 CONCENTRATIONS

18 CO 2 ISN T THE ONLY GREENHOUSE GAS TO INCREASE

19 HISTORIC TEMPERATURE AND CO 2 CONCENTRATIONS

20 RECENT TEMPERATURE INCREASES Fluctuations in temperature have been occurring since before humans Explanations for increasing temperatures: IPCC

21 COMPUTER MODELS

22 FEEDBACKS CAN INCREASE OR DECREASE THE IMPACT OF CLIMATE CHANGE

23 CONSEQUENCES TO THE ENVIRONMENT BECAUSE OF GLOBAL WARMING Melting of polar ice caps/ Greenland and Antarctica melting Melting of many glaciers around the world Melting of permafrost Rising of sea levels due to the melting of glaciers and ice sheets and as water warms it expands Heat waves Cold spells Change in precipitation patterns Increase in storm intensity Shift in ocean currents

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25 CONSEQUENCES TO LIVING ORGANISMS Wild plants and animals can be affected Growing season for plants has changed Ranges occupied by variety of species have been shifting towards both poles Potential harm if animals can t move to better climates Coral are especially sensitive to global warming Humans: May have to relocate Some diseases could increase Economic consequences

26 THE CONTROVERSY OF CLIMATE CHANGE Fundamental basis of climate change that greenhouse gas concentrations are increasing and that this will lead to global warming is not in dispute among the vast majority of scientists What is unclear is how much world temperatures will increase for a given change in greenhouse gases, because that depends on the different feedback loops

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28 GREENPEACE CO-FOUNDER DOES NOT BELIEVE IN GLOBAL CLIMATE CHANGE Let s watch the video:

29 THE KYOTO PROTOCOL In 1997, representatives of the nations of the world went to Kyoto, Japan to discuss how best to control the emissions contributing to global warming Agreement that emissions of greenhouse gases from all industrialized countries will be reduced to 5.2% below their 1990 levels by 2012 Countries agreed to different levels of emission restrictions Options to reduce emissions: Increase fuel efficiency and switching from coal/oil to natural gas/renewable energy/nuclear energy Carbon sequestration next slide

30 CARBON SEQUESTRATION Approach involving taking CO2 out of the atmosphere Some methods: Researchers are looking at cost-effective ways of capturing CO2 from the air, from coal-burning power stations, and from other emission sources Captured CO2 would be compressed and pumped into abandoned oil wells or the deep ocean.

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32 DATES FOR THE KYOTO PROTOCOL 1997 US Senate voted unanimously that US should not sign due to a lack of restrictions on developing countries or any agreement that would harm US economy 2001 KP modified to convince more developed nations to ratify GWB argued too much uncertainty in global warming predictions to justify ratification of protocol 2007 EPA given authority (and must) to regulate greenhouse gases as part of Clean Air Act 2009 EPA announced start of regulating greenhouse gases for 1 st time 2010 EPA starts to look more closely at ways to regulate emissions of CO countries have ratified the Kyoto Protocol US is only developed country who has not ratified Changes in country CO2 emissions: When look at all 41 developed countries reduction was 5.2%