Global Climate Change
David Karowe
Department of Biological Sciences
Western Michigan University
Temperature Anomaly (oC)
Since 1900, Earth has warmed ~ 0.8o C
14 warmest years in history:
2001-2013, 1998*
*
Warming is 10-20 times faster than
in at least the last 800,000 years
1
Temperature difference relative to 1950-1980
http://data.giss.nasa.gov/gistemp/animations/
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1950-1959
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At the same time, much of the world has been
experiencing more frequent and stronger droughts
Palmer Drought Severity Index (PDSI)
2
At the same time, much of the world has been
experiencing more frequent and stronger droughts
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1950-1959
2000-2009
Palmer Drought Severity Index (PDSI)
Much of the U.S. has been experiencing severe drought
September 2012
77% drought
3
Is the U.S. still in drought?
April 1: 53% drought
This winter, most of the world was not like Michigan
January 2014 Temperatures
4
“Natural variation” cannot explain current warming
Recently, while Earth has been warming fastest,
solar irradiance has been decreasing
Temperature
Solar Irradiance
1900
1925
1950
1975
5
In two major ways, current warming is
very different than any warming period
in at least the last 800,000 years
1. It’s at least 10-20 times faster
2. It’s happening while solar input is decreasing
Best estimate: > 95% of current warming
is due to human activities
6
Are Americans aware of the cause?
“We’re causing it”
“It’s natural”
Is there any debate among scientists about whether
humans are the primary cause of global warming?
“Most of the global warming in recent decades can
be attributed to human activities."
Scientific organizations endorsing this statement:
United States:
National Academy of Sciences
American Medical Association
American Association for the Advancement of Science
American Meteorological Society
American Institute of Biological Sciences
American Chemical Society
American Geophysical Union
American Institute of Physics
7
Geological Society of America
American Academy of Paediatrics
American College of Preventive Medicine
American Public Health Association
National Oceanic and Atmospheric Administration
National Aeronautics and Space Administration
Environmental Protection Agency
National Center for Atmospheric Research
University Corporation for Atmospheric Research
Ecological Society of America
American Society of Agronomy
American Society of Plant Biologists
Association of Ecosystem Research Centers
Botanical Society of America
Crop Science Society of America
Natural Science Collections Alliance
American Statistical Association
Organization of Biological Field Stations
American Physical Society
Society for Industrial and Applied Mathematics
Society of Systematic Biologists
Soil Science Society of America
Federation of American Scientists
National Research Council
National Association of Geoscience Teachers
American Quaternary Association
American Association of Wildlife Veterinarians
American Society for Microbiology
Society of American Foresters
American Astronomical Society
8
Europe:
European Academy of Sciences and Arts
European Science Foundation
European Geosciences Union
European Physical Society
European Federation of Geologists
Norwegian Academy of Science and Letters
Royal Society of the United Kingdom
Academie des Sciences (France)
Deutsche Akademie der Naturforscher (Germany)
Accademia dei Lincei (Italy)
Royal Irish Academy
Royal Swedish Academy of Sciences
Royal Academy of Belgium for Sciences and the Arts
Royal Meteorological Society
British Antarctic Survey
Other countries (≥ 35):
Chinese Academy of Sciences
Science Council of Japan
Russian Academy of Sciences
Indian National Science Academy
Royal Society of New Zealand
Australian Academy of Sciences
Australian Medical Association
Polish Academy of Sciences
Academia Brasiliera de Ciencias (Brazil)
Royal Society of Canada
African Academy of Sciences
Caribbean Academy of Sciences
Academy of Sciences of Malaysia
Indonesian Academy of Sciences
Academy of Science of South Africa
9
Scientific organizations holding a dissenting opinion:
2007:
American Institute of Petroleum Geologists
Since 2008:
None
Are Americans aware of the strength of the
scientific consensus?
In fact, 97.5% of climate scientists agree
“Scientists agree”
“Scientists don’t agree”
10
What does the future hold?
It depends on our choices
If we remain on our current course,
future climate change will be severe
Depending
on choices
we make,
Earth is
likely to
warm by
2-5o C
by 2100
Actual
“Business
as usual”
Alternate energy
sources
5o
4o
2o
11
And warming will be greater at higher latitudes
Lower
Emissions
Higher
Emissions
Will a 5o temperature rise matter?
When Earth was 5o cooler:
12
Most summers are likely to be hotter than any
experienced thus far
Most summers are likely to be hotter than any
experienced thus far
13
Michigan will experience many more days over 90o F
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2060-2069
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Much of the world is likely to experience much more
frequent and stronger droughts by the 2060s
Palmer Drought Severity Index (PDSI)
- current drought indices will longer be sufficient
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How will climate change affect species?
Again, it depends on our choices
If we remain on our current course, there will be
serious adverse consequences for most species
With 2o warming: 40% of 5,200 African plant species
are predicted to go extinct
15
Climate change is predicted to cause the extinction
of 20-40% of large African mammals by 2080
Coral reef species are particularly vulnerable
because both warming and ocean acidification can cause
bleaching
16
Even 2o warming is likely to cause a massive increase
in bleaching events
How will climate change affect species in Norway?
17
Some bird species in Norway are migrating earlier
Snow Bunting
Ringed Plover
- but others are not
Sedge Warbler
Red Knot
Many Norwegian birds are likely to lose habitat
Scandinavian bird species
are predicted to lose 80%
of their suitable habitat by
2080
18
All of Norway’s mountain bird species
are predicted to be “climate losers”
Mountain plants in Norway are likely to be less
sensitive to climate change than elsewhere in Europe
Warming
Precipitation
- extinction predicted for only 10% of alpine species in
the Norwegian Scandes (50% extinction elsewhere in
Europe
19
Spruce forests in Norway are likely to expand
Today
2100
Climate change is likely to cause an increase in
marine fish catch for Norway
- but a decrease in tropics and Southern Ocean
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Developed countries are causing the problem, but
developing countries experience most health costs
Countries proportional to
CO2 emissions (1950-2002)
Countries proportional to
climate-sensitive health effects
Even more widespread and serious, according to the
preponderance of evidence from scientists worldwide
…[is] dangerous global warming, caused by the buildup
of greenhouse gases, especially carbon dioxide.
21
www.lutheransrestoringcreation.org
“The earth is a planet of beauty and abundance; the earth
system is wonderfully intricate and incredibly complex. But
today living creatures, and the air, soil, and water that
support them, face unprecedented threats. Many threats are
global; most stem directly from human activity. Our current
practices may so alter the living world that it will be unable
to sustain life in the manner we know.” (ELCA, “Caring for
Creation: Vision, Hope, and Justice,” 1993)
What can I do to minimize climate change?
We can change the future by implementing
multiple solutions that already are available
22
Weatherize your house: weather-strip, adequately
insulate attic, and replace single-pane windows
with triple-pane windows
Next time, buy a more fuel-efficient car
20 mpg
34 mpg
30 mpg
50 mpg
23
Unfortunately, energy conservation is not a solution
- really just delays the outcome
67% of U.S. electricity is generated
by burning coal or gas
Coal
Gas
24
To limit warming to 2o C, we need to reduce
greenhouse gas emissions by 80% by 2050
This can only happen through aggressive expansion
of alternate energy sources
Solar
Wind
Globally, we generate only 0.2% of our energy from wind,
and only 0.1% from solar
Global wind potential is >40 times worldwide use
All 9 highest CO2-emitting countries could use wind alone
183x
23x
183x
30x
8x
18x
3x
3x
8x
25
Wind power in Michigan could supply 12 times
current statewide electricity demand
The “intermittency problem” can be solved easily
e.g. Luddington pumped storage plant
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Solar energy has even greater potential
More energy reaches Earth
from the sun in 1 hour than
humans on the entire
planet use in 1 year!
Three main solar electricity technologies:
solar tower
parabolic trough
photovoltaics
Global potential estimated at up to 100 times current use
27
A small portion of the Sahara desert could supply all
of the world’s electricity
A solar array 100 x 100 miles could provide all of US
energy needs today
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Again, “intermittency problem” can be solved easily
solar tower
parabolic trough
- store excess heat during day, generate electricity at night
Sooo… we’re not doing it now because the cost is
much higher than electricity from coal, right?
29
The true costs of wind and solar are already
lower than coal-generated electricity
True cost per kilowatt hour of power
Coal:
26¢
Offshore wind:
Onshore wind:
Solar troughs:
Solar towers:
3¢
6¢
11¢
20¢
Solar PV:
40¢
Educate others
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Encourage policymakers to make smarter choices
MI 6th District voters will have a clear choice
What would we gain by making these smarter choices?
Probability of species extinctions
3.5o C
Warming
2o C
Warming
Low
Moderate
High
31
Worst case scenario:
< 0.01%
0.3%
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