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CHAPTER 19
Global Change
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
ef fect of global warming on ice cap posed greatest threat to
polar bears
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
THE GREENHOUSE EFFECT
THE GREENHOUSE EFFECT
 Greenhouse gases – gases that
absorb infrared radiation
 Include:
 Make up small percentage of
atmosphere
 IMPORTANT!
MAJOR GREENHOUSE GASES
NATURAL GREENHOUSE GASES
 Volcanic eruptions – mainly carbon dioxide
 Also releases ash
 Methane – from decomposition
 Nitrous oxide – from denitrification
 Water vapor – evapotranspiration or evaporation
ANTHROPOGENIC CAUSES OF
GREENHOUSE GASES
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Burning of fossil fuels
Agricultural practices
Deforestation
Landfills
Industrial production- CFC’s are an example
ANTHROPOGENIC SOURCES OF
GREENHOUSE GASES
ANTHROPOGENIC SOURCES OF
GREENHOUSE GASES IN US
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:
INCREASING CO 2 CONCENTRATIONS
 David Keeling began measuring CO 2 in 1958.
EMISSIONS FROM THE DEVELOPED AND
DEVELOPING WORLD
GLOBAL TEMPERATURES SINCE 1880
 Since 1880 temperatures have increased 0.8 °C.
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
HISTORIC CO 2 CONCENTRATIONS
CO 2 ISN’T THE ONLY GREENHOUSE GAS
TO INCREASE
HISTORIC TEMPERATURE AND CO 2
CONCENTRATIONS
RECENT TEMPERATURE INCREASES
 Fluctuations in temperature have been occurring since before
humans
 Explanations for increasing temperatures:
 2007 - IPCC
COMPUTER
MODELS
FEEDBACKS CAN INCREASE OR DECREASE THE
IMPACT OF CLIMATE CHANGE
CONSEQUENCES TO THE ENVIRONMENT
BECAUSE OF GLOBAL WARMING
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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 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
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
GREENPEACE CO-FOUNDER DOES NOT
BELIEVE IN GLOBAL CLIMATE CHANGE
 Let’s watch the video:
http://www.youtube.com/watch?v=cA6WZ4SX_ -0
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
CARBON SEQUESTRATION
 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.
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 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%