How Climate Change Threatens Biodiversity
David Karowe
Department of Biological Sciences
WMU
Earth’s climate is always changing
1
Since 1900, Earth has warmed ~ 0.8o C
12 warmest years in history:
2002-2012, 1998*
Warmest year: 2010
- warming is now 20x faster than any time in ice cores
Temperature difference relative to 1950-1980
http://data.giss.nasa.gov/gistemp/animations/
2
Solar Irradiance
While Earth has been warming fastest, energy from
the sun has decreased
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 Association for the Advancement of Science
American Medical Association
American Meteorological Society
American Institute of Biological Sciences
American Chemical Society
American Geophysical Union
American Institute of Physics
3
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
4
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
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
5
Scientific organizations holding a dissenting opinion:
American Institute of Petroleum Geologists
Since 2008: None
Best estimate: at least 95% of current warming is
due to human activities
Greenhouse gas emissions
Deforestation
6
Precipitation is a very important component of climate
- severe rainstorms have become more common
- 20% increase in Michigan since 1948
- 50% increase in southwest Michigan
Much of the world is also already experiencing
more frequent and stronger droughts
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1950-1959
Palmer Drought Severity Index (PDSI)
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Much of the world is also already experiencing
more frequent and stronger droughts
Palmer Drought Severity Index (PDSI)
Arctic summer sea ice has been decreasing rapidly
- record low in 2012
8
Arctic summer sea ice has been decreasing rapidly
August 27, 2012
- record low in 2012
Greenland ice sheet is melting at an accelerating rate
2012
9
2012 was the warmest year on record for 19 states
- and for the entire contiguous U.S.
10
This year, severe drought covered much of the U.S.
December 2012
74% drought
http://droughtmonitor.unl.edu/archive.html
What does the future hold?
It depends on the choices we make
11
Depending on our actions, Earth is likely to warm by
at least 2-4o C by 2100
“Business
as usual”
4o
2o
0.6o
Alternate
energy
sources
Zero emissions
Will a 4o temperature rise matter?
When Earth was 5o cooler:
12
Arctic is likely to warm at about twice the global rate
- Arctic is site of strongest
positive feedbacks
Many glaciers are likely to disappear by 2100,
including all intertropical glaciers by 2030
- 750,000,000 people in China and India rely on glaciers
and seasonal snowpacks for their water supply
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Much of the world is likely to experience much more
frequent and stronger droughts by the 2060s
2060-2069
1950-1959
2000-2009
Palmer Drought Severity Index (PDSI)
- current drought indices may no longer work properly
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
Many areas are also predicted to experience
“disappearing climates” by 2100
Low
Moderate
High
Probability of disappearing climate
15
How will climate change affect biodiversity?
It depends on the choices we make
What is the likely future fate of species?
16
Climate Envelope Modeling is used to predict
future changes in range and population size
General approach:
a. Determine the levels of important climate variables
(usually temperature and precipitation) that occur within
the species’ current geographic range
b. Use climate models to predict where those levels will exist
in the future
c. Make an assumption about dispersal (usually “full” or
“none”)
d. Compare current and future suitable area to infer
population increase or decrease
What is the fate of 26 species of European forest herbs?
- woodland horsetail is predicted to decline, due to
shrinking range
current
future
17
- wild peony is predicted to increase, due to increased range
current
future
- but fate of European cohosh is unclear, since it must
migrate to reach its future habitat
?
- even if suitable habitat exists,
species may not be able to
reach it in time
18
Australian Banksia are very dry-adapted species,
so will they be “climate winners”?
Typical result: many more climate losers than winners
Under 2o warming with full dispersal: 21 winners
80 losers (5 go extinct)
Under 4o warming with no dispersal:
0 winners
97 losers (24 go extinct)
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Under 2o warming, huge losses are predicted for
5,200 African plant species
40% of species go extinct (full dispersal)
55% of species go extinct (no dispersal)
Tree diversity is predicted to decline substantially
throughout the U.S. by 2100
Current
2100
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By 2080, climate change is predicted to cause the
extinction of 20-40% of large African mammals
Which species are particularly vulnerable?
1.
2.
3.
4.
Species that have nowhere to go
Species that live in the tropics
Species that have specific timing requirements
Species that live in coral reefs
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High latitude species may have nowhere to go
- most, but not all,
polar bear populations
are predicted to decline
drastically by 2050
Alaska
Seals also rely on sea ice, so are highly vulnerable too
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Scandinavian bird species are predicted to lose 80%
of their suitable habitat by 2080
In Antarctica, Emperor and Adelie penguins need ice,
so will be climate losers
but Chinstrap and Gentoo penguins nest on land, so
will be climate winners
23
High altitude species may also have nowhere to go
Globally, 18% of Earth’s 1,009 montane bird species
are predicted to lose at least half of their range by 2100
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Tropical species have narrow temperature ranges, and
are very likely to experience “disappearing climates”
Low
Moderate
High
Probability of disappearing climate
Where do most of Earth’s species live?
Migrating species are likely to be vulnerable because
of their specific timing requirements
- due to loss of synchrony at important stopover sites
- daylength and star patterns
vs. temperature
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Species that have not been tracking climate change are
already declining
- in Thoreau Woods over the last 150 years, major
declines for plant species with no phenological shift
Blueberry family
Rose family
Dogwood family
- European bird species that are not
migrating earlier are also declining
Pied flycatcher
Coral reef species are likely to be particularly vulnerable
because both warming and ocean acidification can cause
bleaching
26
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
27
Climate change has the potential to cause
Earth’s 6th mass extinction
What will climate change mean for Michigan species?
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In Michigan, 22 tree species are predicted to decline by
50-100% by 2100, including:
sugar maple
balsam fir
American beech
big tooth and trembling aspen
northern white cedar
20 southern species are predicted to arrive in Michigan
loblolly pine
sweetgum
shortleaf pine
Virginia pine
sugarberry
29
50 Michigan bird species predicted to decline by 50-100%
Common loon
Evening
grosbeak
White-throated
sparrow
Red-breasted
nuthatch
Veery
Magnolia
warbler
Yellow-bellied
sapsucker
Blackburnian
warbler
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
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What can I do to minimize climate change?
1. Next time, buy a more fuel-efficient car
20 mpg
34 mpg
30 mpg
50 mpg
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2. Weatherize your house: weather-strip, adequately
insulate attic, and replace single-pane windows
with triple-pane windows
Unfortunately, energy conservation is not a solution
50 mpg
- really just delays the inevitable
32
To avoid worst scenarios, we need to rapidly and
substantially reduce greenhouse gas emissions
Target: 80% reduction by 2050
Urgent need for alternate energy sources
Solar
Wind
Wind power could supply 16 times current U.S.
electricity demand using only onshore windmills
- Michigan can supply 12 times our current use
33
Concentrating Solar Power (CSP) is very promising
Central tower
Parabolic trough
A CSP solar array 100 x 100 miles could provide
all of U.S. electricity needs today
- excess energy captured during the day could be stored
as heat and used to produce electricity at night
34
A small portion of the Sahara desert could supply all
of the world’s electricity
Who has the largest impact on Earth’s future?
“… one of the
biggest threats to
planet Earth on
planet Earth.”
LA Times,
December 2011
3. Vote
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4. Educate others
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. Many of the worst scenarios can be avoided by
choices we have available today
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Worst case scenario:
Thank you for listening
Now please talk with others
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