Global Change CHAPTER 19
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Global Change CHAPTER 19
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
WALKING ON THIN ICE
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
GLOBAL CHANGE
THE GREENHOUSE EFFECT
Greenhouse gases – gases that absorb infrared radiation Include: Make up small percentage of
atmosphere IMPORTANT!
THE GREENHOUSE EFFECT
MAJOR GREENHOUSE GASES
Volcanic eruptions – mainly carbon dioxide Also releases ash
Methane – from decomposition Nitrous oxide – from denitrification Water vapor – evapotranspiration or evaporation
NATURAL GREENHOUSE GASES
Burning of fossil fuels Agricultural practices Deforestation Landfills Industrial production- CFC’s are an example
ANTHROPOGENIC CAUSES OF GREENHOUSE GASES
ANTHROPOGENIC SOURCES OF GREENHOUSE GASES
ANTHROPOGENIC SOURCES OF GREENHOUSE GASES IN US
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:
IPCC
David Keeling began measuring CO 2 in 1958.
INCREASING CO2 CONCENTRATIONS
EMISSIONS FROM THE DEVELOPED AND DEVELOPING WORLD
Since 1880 temperatures have increased 0.8°C.
GLOBAL TEMPERATURES SINCE 1880
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
TEMPERATURES AND GREENHOUSE GAS CONCENTRATIONS IN PAST 400,000 YEARS
HISTORIC CO2 CONCENTRATIONS
CO2 ISN’T THE ONLY GREENHOUSE GAS TO INCREASE
HISTORIC TEMPERATURE AND CO2 CONCENTRATIONS
Fluctuations in temperature have been occurring since before humans Explanations for increasing temperatures:
2007 - IPCC
RECENT TEMPERATURE INCREASES
COMPUTER MODELS
FEEDBACKS CAN INCREASE OR DECREASE THE IMPACT OF CLIMATE CHANGE
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
CONSEQUENCES TO THE ENVIRONMENT BECAUSE OF GLOBAL WARMING
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
CONSEQUENCES TO LIVING ORGANISMS
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
THE CONTROVERSY OF CLIMATE CHANGE
Let’s watch the video: http://www.youtube.com/watch?v=cA6WZ4SX_-0
GREENPEACE CO-FOUNDER DOES NOT BELIEVE IN GLOBAL CLIMATE CHANGE
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
THE KYOTO PROTOCOL
Approach involving taking CO2 out of the atmosphere Some methods:
Researchers are looking at cost-ef fective 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.
CARBON SEQUESTRATION
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
1st time 2010 – EPA starts to look more closely at ways to regulate
emissions of CO2 2010 – 190 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%
DATES FOR THE KYOTO PROTOCOL
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