a presentation developed by the national academy of sciences based on its report ecological impacts...

A presentation developed by the National Academy of Sciences based on its report Ecological Impacts of Climate Change (2009): www.nas.edu/climatechange.

National Academy of SciencesNational Academy of Engineering

Institute of MedicineNational Research Council

The Climate is Changing

• Temperatures are rising• Sea levels are rising• The ocean is acidifying• Climate change is reflected

in water cycle changes and in extreme weather

Temperature rise, indicated by color (red=higher rate of increase). Earth’s surface

temperature has risen ~1.3˚ F since 1850.

Image courtesy of the Joint Institute for the Study of the Atmosphere & Ocean, U. of Washington.



Ecological Impacts

Living things are intimately connected to their physical surroundings.

Ecosystems are affected by changes in: – temperature– rainfall/moisture– pH

– salinity (saltiness)– activities & distribution of other species– …many other factors



Ecological Impacts

As a result of climate change, species and ecosystems are experiencing changes in: – ranges– timing of biological activity– growth rates– relative abundance of species

– cycling of water and nutrients– the risk of disturbance from fire,

insects, and invasive species



Ecological Impacts

• As a result of climate change, species and ecosystems are experiencing changes in: – ranges– timing of biological activity– growth rates– relative abundance of species





Range Shifts

Species are relocating to areas with more tolerable climate conditions.

Range shifts particularly threaten species that: – cannot move fast enough – depend on conditions that are

becoming more rare (like sea ice)

Plant hardiness zone maps, 1990 and 2006. Most zones shifted northward in this period.

Map courtesy of the National Arbor Day Foundation.



Ecological Impacts

As a result of climate change, species and ecosystems are experiencing changes in: – ranges– timing of biological activity– growth rates– relative abundance of species





Timing of Biological Activity

Some seasonal biological activities are happening 15-20 days earlier than several decades ago: – Trees blooming earlier– Migrating birds arriving earlier– Butterflies emerging earlier

Changes in timing differ from species to species, so ecological interactions are disrupted.

European pied flycatcher chicks are now born later than the caterpillars they eat.

Images used under the terms of the GNU Free Documentation License.



Global Changes, Local ImpactsAlthough climate change is global, the

ecological impacts are often local.

What’s happening in your backyard?



Impacts in the Pacific CoastlineShifting Ranges of Checkerspot Butterflies• Edith’s checkerspot: range has shifted northward and to higher

elevations over 40+ years

• Quino checkerspot: first endangered species for which climate change is officially listed as a threat and as a factor in the plan for its recovery

Image courtesy of Dr. Gordon Pratt, www.quinocheckerspot.com.



Impacts in the Pacific CoastlineChanges in the Water• Shift in species ranges: many

species moving northward

• Mysterious dead zones along Washington and Oregon coastline: cause undetermined but potential links to climate change

Scientists retrieve a water sample for research on a recurring “dead zone” off the coasts of Washington and Oregon.

Image courtesy of Oregon State University.



Impacts in the Pacific CoastlineCalifornia Wine Industry: Unwelcome Changes?• Climate change affects managed ecosystems like vineyards and

farms just as it affects natural ecosystems

• Future warming unlikely to help wine growers in California’s premium wine regions: some areas projected to become “marginal” by 2100



Impacts in Alaska and the ArcticEffects on Ice-Dependent Animals• Year-round sea ice shrinking: walruses and other animals

challenged to find platforms for nursing and resting

• Polar bears facing difficult hunting conditions: seals now surfacing in open ocean instead of holes in ice



Impacts in Alaska and the ArcticChanging Food Chains• Increased shrub growth presenting

a threat to caribou (wild reindeer)

– Shrubs crowding out lichens (a key winter food for caribou)

– Shrubs collect snow, causing deep snowdrifts: deep snow makes it hard for caribou to reach lichens hidden beneath



Impacts in Alaska and the ArcticFeedback Loops: Arctic Warming Faster• The Arctic is warming twice as fast as the rest of the planet

– As sea ice and seasonal snow cover melts, previously reflective white surfaces converted to darker surfaces (to ocean water or vegetation)

– Thawing permafrost releases carbon dioxide and methane into the atmosphere, increasing greenhouse gases

Rate of warming, indicated by colors (red=higher rate).

Image created with data from the Goddard Institute for Space Studies.



Impacts in Western MountainsWildfire, Drought, and Insects: Complex InteractionsClimate change increases the risk of fire in areas where decades of total

fire suppression have resulted in buildup of dead fuels.

Wildfire increasing in frequency, size, season length:

– Longer, more intense summer droughts stressing trees

– Stressed trees are more susceptible to attacking beetles, which leave standing dead fuels in their wake

A wildfire in Bitterroot National Forest, Montana.

Image courtesy of John McColgan, USDA Forest Service.



Impacts in Western MountainsEffects on The American Pika• Climbing to higher elevations in

response to warming

• Many populations now isolated on “mountaintop islands”

Pika images courtesy of J. R. Douglass, Yellowstone National Park; Aerial image courtesy NASA.



Impacts in Western MountainsChanges in Trout Habitat• Earlier springs, warmer summers reducing stream flows as

mountain snow melts off earlier in the season

• Some streams reaching temperatures lethal to trout (>78˚F)

Image courtesy USGS.



Impacts in Southwestern Deserts

Wildfire and Invasive Species • Nonnative grasses becoming

established in deserts:

– Red brome (in the Mojave)– Buffelgrass (in the Sonoran)

• Grasses transform desert into flammable grassland: fire-adapted grasses re-establish quickly, pushing out native species like Saguaro cactus

• Spread of grasses not directly a result of climate change, but warming may allow them to further spread in the desert and extend to higher elevations.

Image courtesy T. Esque, USGS.



Impacts in Southwestern Deserts

The Piñon Pine: Past a Tipping Point• Drought in 2000-2003 stressed a large swath of piñons, leaving

them susceptible to infestation by pine bark beetles• This example shows how a stressful event can trigger dramatic

ecological change when an ecosystem is subject to many interacting stresses

2002 2004

Images courtesy D. Allen, USGS.



Impacts in the Central U.S.Agricultural Impacts• Difficult to pinpoint climate impacts:

climate change occurring along with improvements in farming techniques

• In general, plants may:

– Grow faster (increasing yields unless it becomes too warm or crops mature too early)

– Be affected by carbon dioxide levels (increased growth for some plants, not for others)

• Good information about changes and adaptive practices is essential for farmers



Impacts in the Central U.S.Migratory Waterways: Drying Up? • “Playa lakes” or “Prairie potholes” essential for migrating birds: used

for resting, feeding, and mating

• Climate change, combined with other pressures (irrigation demands, pollution, etc.), may dry up these important waterways

Image courtesy of the U.S. Fish and Wildlife Service.



Impacts in the Southeast

Challenges to Everglades Restoration Everglades has shrunk due to human manipulation of the region’s

water; ongoing efforts aim to restore the ecosystem.

• Climate change impacts (increasing water temperature, changes in precipitation) may make restoration efforts more difficult

1850 Today

Images courtesy Rodney Cammauf, National Park Service (panther); South Florida Water Management District (maps)




Sea-level Rise • Fragments barrier islands, reconfigures

shorelines

• May leave certain ecosystems struggling to adapt—in particular those adapted to the conditions between land and sea

• Landward movement of mangroves and marshes may be inhibited by human development




Coral Reefs: Multiple Changes• Climate change is compounding other

factors affecting reefs (coastal development, pollution, overfishing)

• Heat stress causes coral bleaching: corals expel symbiotic algae, leaving white “bones” behind (deadly to coral if long-lasting)

• Ocean acidification affects marine organisms’ ability to build shells and skeletons: likely to slow or stop the growth of coral by 2100

Image courtesy of NOAA.

Coral bleaching




Northward Movement of Tropical Species• Bird and butterfly watchers across the Southeast looking out for new

species; some former seasonal migrants now staying year-round

The rufous hummingbird has become a year-round resident in

Alabama.

Image courtesy Dean E. Briggins, U.S. Fish and Wildlife Service.



Impacts in the NortheastFisheries• Cod: affected by water temperature

– Habitat may become restricted to cooler pockets (<54˚F for adults, <46˚F for young)

• Lobsters: affected by oxygen levels

– Warmer water holds less oxygen: oxygen becomes insufficient for lobsters >79˚F

– In north, warming may improve lobster habitat

• Oysters: Deadly parasite Perkinsus marinus moving northward

– Range expanded from Chesapeake Bay to Maine: shift linked to above-average winter temperatures



The Role of Human Beings

Causes of Climate Change• It is very likely that most of the

climate change in the current era is the result of human activities.

– Human activities have increased concentrations of greenhouse gases in the atmosphere.

– These gases trap heat and cause the Earth to warm.

Figure adapted from Climate Change 2007: The Physical Science Basis. Working Group 1 Contribution to the 4th Assessment Report of the Intergovernmental Panel on Climate Change. Figure SPM.5. Cambridge University Press.




Rate of Climate Change• Climate change in the current era is expected to be extremely

rapid compared to transitions in and out of past ice ages.

• Ecosystems are more vulnerable to changes that happen rapidly.

A scientist holding an ice core—a sample taken from polar ice caps or mountain glaciers.

Ice cores reveal clues about climate changes in Earth’s past.

Image courtesy USGS National Ice Core Laboratory.




Compounding Factors• Human activities have many other effects on ecosystems.

• These effects compound the effects of climate change, making it more difficult for ecosystems to adapt.

– Pollution– Habitat fragmentation– Invasive species

– Overfishing– Manipulation of water sources– …and much more




Improving the Outlook• Changes in activities at the personal, community, and national

levels can affect the rate of future climate change and species’ abilities to adapt.

• Some of the areas where changes in human activities could help species adapt include:

– Approaches to agriculture– Water management practices– Energy sources and use– Transportation – Pollution remediation– Biological conservation– …and much more



The climate challenge is large and complex.

But it is very likely that many people, working from many

angles, can help address climate change and its

ecological consequences.



AcknowledgmentsThis presentation was developed by the National

Academy of Sciences based on its report, Ecological Impacts of Climate Change (2009). The report, its companion booklet, and this presentation were produced with support from the United States Geological Survey. Ecological Impacts of Climate Change was authored by the following National Research Council committee:

National Research Council StaffANN REID, Study DirectorFRANCES E. SHARPLES, Director, Board on Life SciencesANNE FRANCES JOHNSON, Communications OfficerAMANDA CLINE, Senior Program Assistant

CHRISTOPHER B. FIELD, Chair, Carnegie Institution for ScienceDONALD F. BOESCH, U. of Maryland Center for Environmental ScienceF. STUART (TERRY) CHAPIN III, University of AlaskaPETER H. GLEICK, Pacific InstituteANTHONY C. JANETOS, University of MarylandJANE LUBCHENCO, Oregon State UniversityJONATHAN T. OVERPECK, University of ArizonaCAMILLE PARMESAN, University of TexasTERRY L. ROOT, Stanford UniversitySTEVEN W. RUNNING, University of MontanaSTEPHEN H. SCHNEIDER, Stanford University

Unless otherwise noted, all images in this presentation are © JupiterImages, 2009. These images were purchased for use in this presentation and may not be reproduced without permission from the owner.

For more information, visit www.nas.edu/climatechange



a presentation developed by the national academy of sciences based on its report ecological impacts...

Documents

national arbor day foundation

range shifts species

earlier changes

result of climate change

joint institute

water cycle changes

ecological interactions

tolerable climate conditions