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CLIMATE CHANGE OR THE END
OF THE WORLD AS WE KNOW IT
Louis Pasteur
 “You bring me the deepest joy that can be
felt by a man whose invincible belief is that
Science and Peace will triumph over
Ignorance and War, that nations will unite,
not to destroy, but to build, and that the
future will belong to those who will have
done most for suffering humanity.”
Barack Obama 8/28/08
 And for the sake of our economy, our security, and the
future of our planet, I will set a clear goal as President: in
ten years, we will finally end our dependence on oil from
the Middle East.
Washington's been talking about our oil addiction for the
last thirty years, and John McCain has been there for
twenty-six of them. In that time, he's said no to higher
fuel-efficiency standards for cars, no to investments in
renewable energy, no to renewable fuels. And today, we
import triple the amount of oil as the day that Senator
McCain took office.
Barack Obama
 Now is the time to end this addiction, and to understand that drilling
is a stop-gap measure, not a long-term solution. Not even close.
 As President, I will tap our natural gas reserves, invest in clean coal
technology, and find ways to safely harness nuclear power. I'll help
our auto companies re-tool, so that the fuel-efficient cars of the
future are built right here in America. I'll make it easier for the
American people to afford these new cars. And I'll invest 150 billion
dollars over the next decade in affordable, renewable sources of
energy - wind power and solar power and the next generation of
biofuels; an investment that will lead to new industries and five
million new jobs that pay well and can't ever be outsourced.
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch08.pdf
 Models are
tested to see
how well
they predict
the past
Carbon dioxide levels already a
danger
 LONDON, England (CNN) -- A team of international
scientists led by Dr James Hansen, director of NASA's
Goddard Institute for Space Studies, say that carbon
dioxide (CO2) levels are already in the danger zone.
 Concentrations of CO2 in the atmosphere
currently stand at 385 parts per million (ppm)
and are rising at a rate of two ppm per year. This
is enough, say the scientists, to encourage
dangerous changes to the Earth's climate.
Projected Arctic Temperature
2000 - 2100
Projected Surface Annual Air
Temperature Changes 1990 - 2090
+12C
+6C
0C
Projected Surface Winter Air
Temperature Changes 1990 -2090
+12C
+6C
0C
Projected Sea Ice Extent
2010 - 2030
2040 - 2060
2070 - 2090
Projected Sea Level Rise
Sea Level Rise Across the Globe
 University of Arizona Sea Level Animation
IPCC AR4 Synthesis Report 11/2007
 Warming of the climate system is
unequivocal, as is now evident from
observations of increases in global
average air and ocean temperatures,
widespread melting of snow and ice, and
rising global average sea level
IPCC AR4 Synthesis Report 11/2007
 Global GHG emissions due to human
activities have grown since pre-industrial
times, with an increase of 70% between
1970 and 2004
IPCC AR4 Synthesis Report 11/2007
 Africa
• By 2020, between 75 and 250 million of people are projected to be
exposed to increased water stress due to climate change;
• By 2020, in some countries, yields from rain-fed agriculture could
be reduced by up to 50%. Agricultural production, including
access to food, in many African countries is projected to be
severely compromised. This would further adversely affect food
security and exacerbate malnutrition;
• Towards the end of the 21st century, projected sea-level rise will
affect low-lying coastal areas with large populations. The cost of
adaptation could amount to at least 5-10% of Gross Domestic
Product (GDP);
• By 2080, an increase of 5-8% of arid and semi-arid land in Africa is
projected under a range of climate scenarios.
IPCC AR4 Synthesis Report 11/2007
 Asia
• By the 2050s, freshwater availability in Central, South, East and
South-EastAsia, particularly in large river basins, is projected to
decrease; Coastal areas, especially heavily-populated megadelta
regions in South, East and South-East Asia, will be at greatest risk
due to increased flooding from the sea and, in some megadeltas,
flooding from the rivers;
• Climate change is projected to compound the pressures on natural
resources and the environment, associated with rapid
urbanization, industrialization and economic development;
• Endemic morbidity and mortality due to diarrhoeal disease
primarily associated with floods and droughts are expected to
rise in East, South and South-East Asia due to projected changes
in the hydrological cycle.
IPCC AR4 Synthesis Report 11/2007
 Australia and New Zealand
• By 2020, significant loss of biodiversity is projected to occur in some
ecologically rich sites including the Great Barrier Reef and Queensland
Wet Tropics;
• By 2030, water security problems are projected to intensify in southern
and eastern Australia and, in New Zealand, in Northland and some
eastern regions;
• By 2030, production from agriculture and forestry is projected to decline
over much of southern and eastern Australia, and over parts of eastern
New Zealand, due to increased drought and fire. However, in New
Zealand, initial benefits are projected in some other regions.;
• By 2050, ongoing coastal development and population growth in some
areas of Australia and New Zealand are projected to exacerbate risks
from sea level rise and increases in the severity and frequency of storms
and coastal flooding.
IPCC AR4 Synthesis Report 11/2007
 Europe
• Climate change is expected to magnify regional differences in Europe’s
natural resources and assets. Negative impacts will include increased
risk of inland flash floods, and more frequent coastal flooding and
increased erosion (due to storminess and sea-level rise);
• Mountainous areas will face glacier retreat, reduced snow cover and
winter tourism, and extensive species losses (in some areas up to 60%
under high emissions scenarios by 2080);
• In Southern Europe, climate change is projected to worsen conditions
(high temperatures and drought) in a region already vulnerable to
climate variability, and to reduce water availability, hydropower
potential, summer tourism and, in general, crop productivity;
• Climate change is also projected to increase the health risks due to heatwaves, and the frequency of wildfires.
IPCC AR4 Synthesis Report 11/2007
 Latin America
• By mid century, increases in temperature and associated decreases
in soil water are projected to lead to gradual replacement of
tropical forest by savanna in eastern Amazonia. Semi-arid
vegetation will tend to be replaced by arid-land vegetation.
• There is a risk of significant biodiversity loss through species
extinction in many areas of tropical Latin America;
• Productivity of some important crops is projected to decrease and
livestock productivity to decline, with adverse consequences for
food security. In temperate zones soybean yields are projected to
increase. Overall, the number of people at risk of hunger is
projected to increase (TS; medium confidence).
• Changes in precipitation patterns and the disappearance of
glaciers are projected to significantly affect water availability for
human consumption, agriculture and energy generation.
IPCC AR4 Synthesis Report 11/2007
 Polar Regions
• The main projected biophysical effects are reductions in
thickness and extent of glaciers and ice sheets and sea ice,
and changes in natural ecosystems with detrimental effects
on many organisms including migratory birds, mammals
and higher predators;
• For human communities in the Arctic, impacts, particularly
those resulting from changing snow and ice conditions are
projected to be mixed;
• Detrimental impacts would include those on infrastructure
and traditional indigenous ways of life;
• In both polar regions, specific ecosystems and habitats are
projected to be vulnerable, as climatic barriers to species
invasions are lowered.
IPCC AR4 Synthesis Report 11/2007
 Small Islands
• Sea-level rise is expected to exacerbate inundation, storm surge,
erosion and other coastal hazards, thus threatening vital
infrastructure, settlements and facilities that support the
livelihood of island communities;
• Deterioration in coastal conditions, for example through erosion of
beaches and coral bleaching is expected to affect local resources;
• By mid-century, climate change is expected to reduce water
resources in many small islands, e.g., in the Caribbean and
Pacific, to the point where they become insufficient to meet
demand during low-rainfall periods.
• With higher temperatures, increased invasion by non-native
species is expected to occur, particularly on mid- and highlatitude islands.
IPCC AR4 Synthesis Report 11/2007
 North America
• Warming in western mountains is projected to cause decreased snowpack,
more winter flooding, and reduced summer flows, exacerbating
competition for over-allocated water resources;
• In the early decades of the century, moderate climate change is projected
to increase aggregate yields of rain-fed agriculture by 5-20%, but with
important variability among regions. Major challenges are projected for
crops that are near the warm end of their suitable range or which
depend on highly utilized water resources;
• During the course of this century, cities that currently experience
heatwaves are expected to be further challenged by an increased
number, intensity and duration of heatwaves during the course of the
century, with potential for adverse health impacts;
• Coastal communities and habitats will be increasingly stressed by climate
change impacts interacting with development and pollution.
Warming and Earlier Spring Increase Western U.S.
Forest Wildfire Activity
A. L. Westerling,1,2* H. G. Hidalgo,1 D. R.
Cayan,1,3 T. W. Swetnam4
 The Age of Megafires
 Originally published in Science Express on 6 July 2006
Science 18 August 2006:
Vol. 313. no. 5789, pp. 940 - 943
DOI: 10.1126/science.1128834
Fig. 2. (A) Pearson's rank correlation between annual western U.S. large (>400 ha) forest wildfire
frequency and streamflow center timing
A. L. Westerling et al., Science 313, 940 -943 (2006)
Published by AAAS
Fig. 3. Average difference between early and late snowmelt years in average precipitation from October
through May (A) and average temperature from March through August (B)
A. L. Westerling et al., Science 313, 940 -943 (2006)
Published by AAAS
Fig. 4. Index of forest vulnerability to changes in the timing of spring: the percentage difference in
cumulative moisture deficit from October to August at each grid point in early versus late snowmelt
years, scaled by the forest-type vegetation fraction at each grid point, for 1970 to 1999 (26)
A. L. Westerling et al., Science 313, 940 -943 (2006)
Published by AAAS
Global Bird Populations Face Dramatic Decline In
Coming Decades, Study Predicts
 ScienceDaily (Dec. 20, 2004) — Ten percent of all
bird species are likely to disappear by the year
2100, and another 15 percent could be on the
brink of extinction, according to a new study by
Stanford University biologists. This dramatic loss
is expected to have a negative impact on forest
ecosystems and agriculture worldwide and may
even encourage the spread of human diseases,
according to the study published in the Online
Early Edition of the Proceedings of the National
Academy of Sciences (PNAS) in December.
Stabilization Wedges: Solving the Climate Problem for the
Next 50 Years with Current Technologies
S. Pacala et al., Science 305, 968 -972 (2004)
 Humanity already possesses the fundamental scientific,
technical, and industrial know-how to solve the carbon
and climate problem for the next half-century. A portfolio
of technologies now exists to meet the world's energy
needs over the next 50 years and limit atmospheric CO2
to a trajectory that avoids a doubling of the preindustrial
concentration. Every element in this portfolio has passed
beyond the laboratory bench and demonstration project;
many are already implemented somewhere at full
industrial scale. Although no element is a credible
candidate for doing the entire job (or even half the job)
by itself, the portfolio as a whole is large enough that not
every element has to be used.
Fig. 1. (A) The top curve is a representative BAU emissions path for global carbon emissions as CO2
from fossil fuel combustion and cement manufacture: 1.5% per year growth starting from 7.0 GtC/year
in 2004
S. Pacala et al., Science 305, 968 -972 (2004)
Published by AAAS
Target Atmospheric CO2: Where Should Humanity Aim?
James Hansen,1,2* Makiko Sato,1,2 Pushker Kharecha,1,2
David Beerling,3Valerie Masson-Delmotte,4 Mark Pagani,5
Maureen Raymo,6 Dana L. Royer,7 James C. Zachos8
Human Impact Report 2009