Five Things Everyone Should Know
About Climate Change
David Karowe
Department of Biological Sciences
Western Michigan University
Temperature Anomaly (oC)
1. Climate change is real, and humans are causing it.
Since 1900, Earth has warmed ~ 0.8o C
12 warmest years in history:
2002-2012, 1998*
Warming is 10-20 times faster than
in at least the last 800,000 years
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Temperature difference relative to 1950-1980
http://data.giss.nasa.gov/gistemp/animations/
Precipitation is a very important component of climate
- severe rainstorms have become more common
40% increase in southwest Michigan since 1948
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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)
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)
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Climate predictions are coming true in the U.S.
In 2011, 10 states had their wettest spring on record
As a result, there was extensive flooding
4
2012 was the warmest year on record for the U.S.
Much of the U.S. has been experiencing severe drought
September 2012
77% drought
5
Is the U.S. still in drought?
September 24: 62% drought
Three lines of evidence against a meaningful
contribution of “natural variation” to current warming
6
Since 1900, most of the heat added to Earth’s climate
is from greenhouse gasses (GHG)
GHG added
~ 2.98 W/m2
the sun added
~ 0.12 W/m2
Recently, while Earth has been warming fastest,
solar irradiance has been decreasing
Temperature
Solar Irradiance
1900
1925
1950
1975
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Models do a good job of replicating past climate
change only if they include anthropogenic factors
anthropogenic
and natural factors
modeled
natural factors only
observed
observed
modeled
- natural factors (the sun and volcanoes) would have
caused a slight cooling since 1900
Best estimate: ≥ 95% of current warming
is due to human activities
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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
Are Americans aware of the cause?
“We’re causing it”
“It’s natural”
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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
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
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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
Europe:
European Academy of Sciences and Arts
European Science Foundation
European Geosciences Union
European Physical Society
European Federation of Geologists
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
United Kingdom Institute of Biology
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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
Scientific organizations holding a dissenting opinion:
Until 2007:
American Institute of Petroleum Geologists
Since 2008:
none
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Are Americans aware of the strength of the
scientific consensus?
In fact, 97.5% of climate scientists agree
“Scientists agree”
“Scientists don’t agree”
Has Earth stopped warming?
This is a deceptive
argument that only
works with 1998 (the
last Super El Nino year)
as the starting point
1998
1999*
1997*
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What does the future hold?
“No fate but
what we make”
It depends on our choices
2. 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
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Will a 5o temperature rise matter?
When Earth was 5o cooler:
Most summers are likely to be hotter than any
experienced thus far
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Most summers are likely to be hotter than any
experienced thus far
Warming is likely to cause sea level rise of 1-2 meters
by 2100
- up to 300 million people could be flooded each year
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Much of U.S. would be affected by 1 meter rise
Much of Florida would also be under water
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So would much of the east coast
Climate change will also include altered
precipitation patterns
Summer Precipitation
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Summer rainfall is predicted to decrease throughout U.S.
Much of the world is likely to experience much more
frequent and stronger droughts by the 2060s
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2060-2069
Palmer Drought Severity Index (PDSI)
- current drought indices will longer work properly
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What will this mean for Earth’s species?
It depends on the choices we make
3. If we remain on our current course, there will be
serious adverse consequences for most species.
With 2o warming: 2,100 of 5,200 African plant species
(40%) are predicted to go extinct
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African mammals are likely to be adversely affected
With 3.5o warming: 55 of 275 species (20%)
are predicted to go extinct
Australian Banksia are very dry-adapted species,
so will they be “climate winners”?
With 2o warming: 21 winners, 80 losers (5 extinctions)
With 4o warming: 10 winners, 91 losers (17 extinctions)
Typical result: many more climate losers than winners
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Even if suitable future habitat exists, species may not
be able to get there in time to avoid extinction
(images courtesy
of Jason Tallant)
This is the worst time in Earth’s history for climate change
Which species are particularly vulnerable?
1. Species that have nowhere to go
2. Species that live in coral reefs
3. Species that live on land in the tropics
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High latitude species have nowhere to go
Most, but not all,
polar bear populations
are predicted to decline
dramatically by 2050
All decline or disappear
by 2100
Alaska
Red = declining
Blue = increasing
All ice-obligate species are highly vulnerable
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In Antarctica, Emperor and Adelie penguins need ice
but Chinstrap and Gentoo penguins nest on land
High altitude species may also have nowhere to go
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All of Earth’s 1,009 montane bird species are
predicted to be “climate losers”
Coral reef species are also particularly vulnerable
because both warming and ocean acidification can cause
bleaching
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Even 2o warming is likely to cause a massive increase
in bleaching events
Acidification alone may make most or all of the ocean
unsuitable for corals
- 650 ppm CO2 may cause near total loss of coral reefs
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Tropical species have narrow temperature ranges,
so are very likely to experience “disappearing climates”
Where do most species live?
Low
Moderate
High
Probability of disappearing climate
Therefore, tropical species are particularly vulnerable
What will happen to plants and animals in Michigan?
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At least 20 common tree species are predicted to
decline by 50-100% in Michigan, including:
-98%
black spruce
-89%
balsam fir
-97%
-89%
paper birch
aspen
-67%
-66%
sugar maple
eastern hemlock
20 southern species are predicted to occur in Michigan
loblolly pine
sweetgum
shortleaf pine
Virginia pine
sugarberry
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But forests are more than just trees
32 Michigan bird species predicted to decline by 75-100%
Common loon
Evening
grosbeak
White-throated
sparrow
Red-breasted
nuthatch
Veery
Magnolia
warbler
Yellow-bellied
sapsucker
Blackburnian
warbler
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15 new species are predicted to arrive in Michigan
northern
bobwhite
Mississippi
kite
yellow-billed
cuckoo
scissor-tailed
flycatcher
little blue
heron
painted
bunting
cattle egret
summer
tanager
4. If we remain on our current course, there will be
serious adverse consequences for human health.
Major ways in which climate change is likely to
affect human health:
1. Increased heat stress and/or decreased cold stress
2. Increased disease
3. Increased malnutrition
4. Change in air quality
5. Change in frequency and/or severity of conflict
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World Health Organization estimates that climate change
already kills 150,000-300,000 people annually
Record hot summers are likely to result in
dramatic increases in heat stress
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For many cities, the number of Chicago 1995-like
heat waves (~700 deaths) will increase dramatically
Chicago 1995-like heat waves per decade
2o C
4o C
Climate change is likely to increase vector-borne diseases
Malaria: World Health Organization estimates
250,000,000 cases and 1,000,000 deaths annually
- every 30 seconds a child dies from malaria
32
Malaria is generally predicted to increase, but change
depends on climate scenario
+ 2o C
+ 4o C
With 2-4o warming:
200-400 million more people at risk worldwide by 2080
About 450 million of the world’s poorest people
depend entirely on agriculture
- grains provide ~ 2/3 of the total human protein intake
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Much more frequent and stronger droughts will
decrease crop yields substantially
2060-2069
1950-1959
2000-2009
Palmer Drought Severity Index (PDSI)
Future U.S. corn and soybean yields are likely to
decrease dramatically
20-25% decrease by 2050
55-60% decrease by 2100
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Coal-fired power plants kill people
J.H.
Campbell
Monroe
2 of the nation’s 10 deadliest power plants are in Michigan
Climate change is predicted to increase civil wars in
sub-Saharan Africa by 50% in the next 20 years
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Most worrisome scenario:
India and Pakistan start a “water war”
- Indus supplies
83% of
Pakistan’s
irrigation
water
Climate change is a major U.S. national security threat
“The effects of climate change in the world’s most
vulnerable regions present a serious threat to
American national security interests. Washington
must lead on this issue now.”
Partnership for a Secure America, February 2013
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Developed countries are causing the problem, but
developing countries suffer most of the effects
Countries proportional to CO2 emissions through 2002:
Countries proportional to climate-related health effects:
What can I do to minimize climate change?
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5. We don’t have to remain on our current course.
We can change the future by implementing
multiple solutions that already are available.
Stop deforestation: great idea, but not a solution
Energy conservation: great idea, but also not a solution
50 mpg
- really just delays the inevitable
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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
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The “intermittency problem” can be solved easily
e.g. Luddington pumped storage plant
Solar energy has even greater potential
Three main technologies:
solar thermal
parabolic trough
photovoltaics
Global potential estimated at up to 100 times current use
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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 thermal
parabolic trough
- store excess heat during day, generate electricity at night
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Educate others
Encourage policymakers to make smarter choices
“… one of the
biggest threats to
planet Earth on
planet Earth.”
LA Times,
December 2011
MI 6th District voters will have a clear choice
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What would Earth gain by these smarter choices?
3.5o C
warming
Low
Moderate
High
Probability of disappearing climate
2o C
warming
Bottom Line:
1. We’re causing climate to change at an
alarming rate.
2. If we continue on our current path, the future
is very likely to include unprecedented
hardships for all of Earth’s species, including
humans.
3. We can change our path by using smarter
choices we have available today.
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