Climate Science Research Review Answers Climate Change Questions
by
Kevin Lustig - 
Update [10/17/2011]: WRI has released the latest edition of Climate Science. After you check out the resources below, take a look at our Q&A with the authors on WRI Insights or read the full report.
With wildfires, floods, tornadoes, and other dramatic weather events making front page news around the world, many people are asking questions about the signs and impacts of a changing climate. Climate Science is the World Resources Institute’s periodic review of the state of play of the science of climate change. With summaries and explanations of recent peer-reviewed research from a host of scientific journals, Climate Science is a window into what scientists are discovering about how climate change affects the living things and complex systems of our planet.
The latest edition, Climate Science 2009-2010 will be released later this year. In the meantime, we have assembled a preview of some of the research covered in the report. Take a look at our slideshow detailing the huge variety of impacts we are already seeing from warming global temperatures, including insights into sea-level rise, human migration, weather extremes, and the shrinking habitats of wildlife. Then, use our interactive map to learn more about the regional consequences of climate change around the United States.
Slideshow:
Climate change impacts around the world
» Explore all of WRI's work on solutions to the climate challenge.
The Global Impacts of Climate Change
Use the arrows above to explore a preview of the research from WRI's upcoming release of Climate Science 2009-2010 and a small selection of the changes facing our warming world.
WRI is working on solutions to the challenges illustrated in this slideshow. Click here to learn more about our work on climate and energy.
Photo Credit: flickr/NASA Goddard Photo and Video
Uneven global sea level rise
Researchers estimate a global sea level rise of approximately 3.26m resulting from the instantaneous melting of the West Antarctic Ice Sheet. Notably, they find that the impacts of the sea level rise would not be uniform around the globe. Because of perturbations in Earth’s rotation and shoreline migration, the impacts are predicted to be most pronounced on the Pacific and Atlantic coasts of the United States, where sea level rise could be 25% higher than the global mean.
Source(s): Bamber, J.L.; Riva, R.E.M.; Vermeersen, B.L.A.; and A.M. LeBrocq. (2009). Reassessment of the potential sea-level rise from a collapse of the West Antarctic Ice Sheet. Science. 324 (901), doi: 10.1126/science.1169335
Photo Credit: flickr/NOAA Photo Library
Changing patterns for wildfires
Increases in both the frequency and extent of wildfire are salient examples of the effects of climate change that can have immediate and significant impacts on human communities. However, there is variation in this trend. Different regions of the world can expect increases or decreases in wildfire distribution from climate change, largely mediated by regionally-specific vegetation and precipitation changes. Notably, the increases in wildfire extent are projected to be in the United States and Canada, Europe and western China. Decreases in wildfire extent are predicted for parts of East Asia, Africa and Australia.
Source(s): Krawchuk MA; Moritz MA; Parisien M-A; Van Dorn J; and K. Hayhoe. (2009) Global Pyrogeography: the Current and Future Distribution of Wildfire. PLoS ONE 4(4): e5102. doi:10.1371/journal.pone.0005102.
Balshi, M.S.; McGuire, A.D.; Duffy, P.; Flannigan,M; Kicklighter, D.W.; and J. Melillo. (2009). Vulnerability of carbon storage in North American boreal forests to wildfires during the 21st century. Global Change Biology. 15: 1491-1510.
Flannigan, M.; Stocks, B.; Turetsky, M.; and M. Wotton. (2009). Impacts of climate change on fire activity and fire management in the circumboreal forest. Global Change Biology. 15: 549-560.
Photo Credit: flickr/slworking2
Growing unpredictability in India's monsoons
A century’s worth of weather data show that summer monsoon rains are becoming less predictable. Agriculture and flood control in India have relied on the predictability of the monsoon over centuries to millennia. A reduction of the predictability of these events has profound implications for the region's agriculture and communities' ability to prepare for oncoming extreme events.
Source(s): Mani, N. J.; Suhas,E; and B. N. Goswami (2009), Can global warming make Indian monsoon weather less predictable? Geophysical Research Letters. 36, L08811, doi:10.1029/2009GL037989.
Photo Credit: flickr/Carlo_it
Extreme heat and the loss of land suitable for human habitation
Human metabolism cannot handle extremely high temperatures well, and a global temperature increase of 7°C, which is the upper limit of current projections, would make large some portions of the world uninhabitable. A global temperature increase of 12°C, which could occur solely from the combustion of all fossil fuel reserves, would render much of the globe uninhabitable by humans. In exploring this possibility, researchers point out that current economic models treat a 10°C rise in temperature as having an equivalent economic effect to a major recession, when it might actually render half the planet uninhabitable.
Source(s): Sherwood, SC and M Huber. (2010). An adaptability limit to climate change due to heat stress. Proceedings of the National Academy of Sciences. 107 (21): 9552-9555.
Photo Credit: flickr/coda
Great Barrier Reef coral bleaching
As atmospheric carbon dioxide (CO2) concentrations rise, the concentration of dissolved CO2 in the oceans has increased as a result, increasing the acidity of ocean water. Acidification can cause great harm to calcifying organisms, such as corals, as their calcium carbonate shells cannot form and, in some cases, dissolve. Research shows that the predicted impacts of ocean acidification are already occurring on the Great Barrier Reef, impacting the health of the reef ecosystem and the livelihoods that depend on such ecosystems.
Source(s): De’ath, G.;, Lough, J.M.; and K.E. Fabricius. (2009). Declining coral calcification on the Great Barrier Reef. Science. 323: 116-119.
Photo Credit: flickr/babasteve
Billions in losses for U.S. fishing industry
Researchers set out to assess the economic effects of ocean acidification using a simple model which links projected declines in mollusk populations from ocean acidification to projected declines in the U.S. commercial mollusk harvest. Using the 2007 harvest as a baseline, the authors calculated potential future losses under different emissions scenarios. Even a modest estimate of 10-25% aggregate decrease in U.S. mollusk harvests could cause anywhere from $1.7 billion to $10 billion in losses to the U.S. fishing industry by 2060.
Source(s): Cooley, S. and S. Doney. (2009). Anticipating ocean acidification’s economic consequences for commercial fisheries. Environmental Research Letters. 4: 024007.
Photo Credit: flickr/marbla123
A later start to a shorter rainy season in the dry Sahel
In the Sahel region of North Africa, climate-induced alterations of rainfall will have profound impacts on agriculture and the resilience and adaptability of human communities. Recent research demonstrates that, by the end of this century, under a mid-range warming scenario, the rainy season will start later by 3-4 days and have a shorter duration by 5 days in the Sahel. These delays and shortenings, while seemingly small, are likely to reduce anticipated crop yields with profound consequences for agricultural production in the region.
Source(s): Biasutti, M.; and A. H. Sobel (2009), Delayed Sahel rainfall and global seasonal cycle in a warmer climate, Geophys. Res. Lett., 36, L23707, doi:10.1029/2009GL041303.
Photo Credit: flickr/SOS Sahel UK
Reduced water supply from the Colorado River
The combined effects of warming temperatures on snowmelt, evaporation, and precipitation will likely have profound influences on river flows, which are critical for human consumption and irrigation of farmland. Researchers estimated the impacts that climate-change induced reductions in runoff from the Colorado River will have for humans' future use of the river's water. Their study predicts a 10-30% reduction in Colorado River run-off by 2050 because of anthropogenic climate change. This will result in significant and regular failure to meet scheduled water deliveries in the American Southwest.
Source(s): Barnett, Tim and David W. Pierce. (2009). Sustainable water deliveries from the Colorado River in a changing climate. Proceedings of the National Academy of Sciences. 106 (18): 7334-38.
Photo Credit: flickr/victorfe places
Hotter growing seasons and widespread crop loss
Researchers have assessed the impacts of increasing temperature on global food supply and found that in the tropics and sub-tropics, it is highly likely (greater than 90% probability) that the average growing season temperature during the last decades of the 21st century will exceed the most extreme temperatures experienced during the 20th century. In temperate regions, temperature extremes like those experienced during the 2003 heat wave in Europe will become the norm. Higher temperature alone will have significant negative effects on crop yields, even without the predicted impacts of associated drought.
Source(s): Battisti, D.; and R. Naylor. (2009). Historical warnings of future food insecurity with unprecedented seasonal heat. Science. 323:240-244.
Photo Credit: flickr/CIMMYT
More destructive hurricanes
Projecting hurricane activity over the rest of the 21st century, researchers found that the frequency of intense hurricanes (category 4 or 5) is likely to increase significantly. Their model projects an increase in the number of intense storms by 80% by the end of the 21st century. They attribute this change to warmer sea surface temperatures. While the overall frequency of hurricanes is likely to decrease, the model suggests that there is a pronounced increase in the frequency of powerful storms after 2070.
Source(s): Bender, MA, Knutson, TR, Tuleya, RE, Sirutis, JJ, Vecchi, GA, Garner, ST, and IM Held. (2010). Modeled impact of anthropogenic warming on the frequency of intense Atlantic hurricanes. Science. 327: 454.
Photo Credit: flickr/NOAA Photo Library
Widespread loss of lizard species around the world
While many reports about climate change focus on projected future impacts, one study set out to assess the impacts of warming temperatures that have already affected populations of lizards around the globe. Analyzing studies of 30 species of Mexican lizards from 1975-2009, they find that 12% of local populations of lizards have gone extinct. Based on the Mexican observations, they estimate that globally, 4% of lizard populations have become extinct since 1975 as a result of climate change. On the basis of the observed trends, the authors find that by 2080, 20% of global lizard species will be extinct.
Source(s): Sinervo, B, Mendez-de-la-Cruz, F, Miles, DB, et al. (2010). Erosion of lizard diversity by climate change and altered thermal niches. Science. 328: 894-899.
Photo Credit: flickr/NOAA Photo Library
Extreme temperature highs in the United States
Researchers project that over the next three decades extreme warm temperatures will increase significantly in the United States. Even when global average temperatures do not rise more than 2°C, one study predicts that by 2030-2039, 38 days of the year will be in the top 5% of current temperature extremes, and that there may be at least seven record setting temperature days per year. Extremes in temperatures can have significant impacts on human health and lives, and reductions in soil moisture and precipitation will have implications for the viability of crops and ecosystems.
Source(s): Diffenbaugh, NS and M Ashfaq. (2010). Intensification of hot extremes in the United States. Geophysical Research Letters. Vol. 37: L15701.
Photo Credit: flickr/yeppiyeebo
Cold winter extremes in Europe and other northern regions
Winter sea ice in the Barents and Kara Seas, portions of the Arctic Ocean north of Russia, has been greatly decreasing due to warming temperatures. This reduction in sea ice cover causes the lower troposphere, (the portion of the atmosphere close to the earth surface) to warm slightly because of the heat trapping ability of the open ocean. On study suggests that this warmer air may create a pressure and temperature gradient that sucks heat out of Europe, resulting in an anomalous continental cooling of -1.5°C (averaged across the continent) in the winter.
Source(s): Petoukhov, V and VA Semenov. (2010). A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents. Journal of Geophysical Research. VOL. 115 doi:10.1029/2009JD013568.
Photo Credit: flickr/neiljs
Major increases in human migration
Changes in land-use patterns and agricultural policies in Mexico and other Central American countries have already been leading to large numbers of migrants into the United States. Climate change is likely to augment this trend as it impacts crop yields in some of the hardest hit and poorest areas of southern Mexico. One study predicts an average of an additional 20,000-100,000 “climate-immigrants” per year over the next decades (assuming a linear rate of increase - Ed, 12/9/11).
Source(s): Feng, S, Krueger, AB, and M Oppenheimer. (2010). Linkages among climate change, crop yields, and Mexico-US cross-border migration. Proceedings of the National Academy of Sciences.
Photo Credit: flickr/Ben Amstutz
Reduction and loss of major Asian sources of drinking water
One of the greatest concerns about the pace and magnitude of human-induced climate change impacts is the water security of the over one billion people in Asia, mostly in India and China, who live in river basins that are fed by Himalayan glaciers and snow. The flows from these water resources are essential to agricultural production and maintaining drinking water supplies. As temperature rises, there are concerns about the long-term stability of these flows. Research has determined that the Indus and the Brahmaputra are most susceptible to climate-induced changes in snow-melt water flow.
Source(s): Immerzeel, WW, van Beek, LPH, and MFP Bierkens. (2010). Climate change will affect the Asian water towers. Science. 328: 1382-1385.
Photo Credit: flickr/reurinkjan
Short-term loss of cloud cover
The sensitivity of the Earth’s climate system to changes in cloud coverage is one of the key uncertainties of the impacts of a changing climate. With a warmer climate, will there be more clouds that reflect more sunlight and thus induce a negative feedback, cooling the earth’s surface, or will there be fewer clouds, and thus a warmer world as more solar radiation hits the earth’s surface? A recent study analyzes data from 2000-2010. Over this time frame, it finds that there appears to be a positive feedback, meaning that warming-induced decreases in cloud coverage has led to more incoming solar radiation, which in turn increases warming.
Source(s): Dessler, AE. (2010). A determination of the cloud feedback from climate variations over the past decade. Science. 330: 1523-1527.
Photo Credit: flickr/Kevin Dooley
Threat of near extinction for Emperor penguin population
Using climate models and observations of Emperor penguin populations over forty three years, researchers found that populations are projected to decline, with the probability of ‘quasi extinction’ (greater than 95% decline) by 2100 at 36%. The impact of early sea ice break up on breeding could have direct effects on penguins’ population growth. Reduced sea ice will likely have indirect impacts on the food web by reducing krill, the primary food source for the fish that penguins eat.
Source(s): Jenouvrier, S.; Caswell, H.; Barbaud, C.; Holland, M.; Stroeve, J.; and H. Weimerskirch. (2009). Demographic models and IPCC climate projections predict the decline of an emperor penguin population. Proceedings of the National Academy of Sciences. 106 (6): 1844-47.
Photo Credit: flickr/Martha de Jong-Lantink
Faster glacial melting due to black carbon
Black carbon, or soot produced from biomass and fossil fuel burning, can alter surface reflectivity, making surfaces darker and warmer, much like a dark shirt on a summer day. Researchers have found that levels of black carbon on Tibetan glaciers are high enough to decrease their surface reflectivity by 10 to 100%. Tibetan glaciers represent the largest stores of freshwater on the planet outside of the polar ice caps. As these glaciers melt rapidly and meltwater seasonality is altered, heavier spring floods and longer dry periods are anticipated throughout East and South Asia.
Source(s): Xu, B.; Cao, J.; Hansen, J.; Yao, T.; Joswia, D.; Wang, N.; Wu, G.; Wang, M.; Zhao, H.; Yang, W.; Liu, X.; and J. He. (2009). Black soot and the survival of Tibetan glaciers. Proceedings of the National Academy of Sciences. 106 (52): 22114-18.
Photo Credit: NASA
Additional sea level rise in the northeast U.S.
There is a difference in the elevation of the sea level near the U.S. coast, with sea levels lower near the coast than further off shore. This “slope” of sea level is a result of a system of robust ocean currents. According to one study, ice melt and precipitation in the Arctic, combined with increased temperatures, are predicted to slow down these currents and eliminate the difference in sea level height. This will increase coastal sea levels an estimated 0.2-0.3m for Boston, New York and Washington, DC by the end of the century in addition to sea level rise from other causes.
Source(s): Yin, J.; Schlesinger, M.E.; and R.J. Stouffer. (2009). Model projections of rapid sea-level rise on the northeast coast of the United States. Nature Geoscience. Doi: 10.1038/NGEO46.
Photo Credit: flickr/InAweofGod'sCreation
Interactive map:
How is climate change impacting the United States?
» Explore all of WRI's work on tackling climate change in the United States.
Click on the colored icons below to explore recent research into the impacts of climate change on U.S. regions: