|
|
|
|
|
|
|
Researchers are now studying ways of adapting to climate change. From the perspective of the Intergovernmental Panel on Climate Change, the question of whether global climate is changing has been resolved. The panel's findings indicate that virtually every glacier in the world is receding and the global sea level is rising as the result of a sustained increase in average temperature. Many biological systems are changing as well, along with the livelihoods of indigenous populations in polar regions.
The panel's 2007 report states that climate changes are expected to continue throughout the 21st century. Increasingly, the extent of these changes, and the degree to which climate changes might be mitigated, are becoming the focus of climate research. Perhaps the most significant shift in the focus of climate research is exploration of ways societies and natural ecosystems might adapt to anticipated, long-term changes in regional climate patterns. Mitigation and adaptation For years the U.S. government has generously funded climate research and, on a smaller scale, studies of mitigation options. Mitigation seeks to lower the risks of climate change by reducing greenhouse gas emissions and slowing deforestation, which releases 20% of the carbon dioxide emissions to the atmosphere. Mitigation options include reducing the use of fossil fuels by relying more on carbon-free nuclear power, solar and wind energy for electricity, and biofuels and batteries for transportation. ORNL researchers are at work on mitigation technologies to improve energy efficiency; increase the uptake of carbon by forests and vegetation, soils and the ocean and enable the capture and sequestration of CO2 during fossil-fuel combustion and conversion processes. Research focused on vulnerability and adaptation to climate change has received comparably less funding, primarily because of the intensity of effort to determine if climate change is, in fact, an aberration or a long-term phenomenon. Adaptation research has been limited in part by the concerns of some that adaptation prospects might undermine a commitment to climate change mitigation efforts, says ORNL Corporate Fellow Tom Wilbanks, one of 47 coordinating lead authors of chapters for the impacts, vulnerability, and adaptation report of the IPCC fourth assessment. Wilbanks coled the chapter entitled "Industry, Settlements, and Society," which includes a section about actions communities can take to reduce exposure to climate change risks. "Now that we see climate change actually happening, we cannot avoid adaptations to some impacts while we try to avoid others," Wilbanks notes, adding that in this context adaptation means learning to live with the impacts of climate change. Improving emergency response capabilities is one example of an adaptation strategy. More than one-half of the U.S. population lives in coastal communities that are vulnerable to flooding if sea levels rise substantially or if hurricanes bring increased amounts of rainfall. Short-term responses for large coastal cities include the decision to build storm-surge barrier seawalls after weighing the risk of frequent flooding against a cost that many might view as prohibitive. A longer-term strategy might be to raise coastal structures over a period of half a century and to encourage changes in land-use policies to reduce exposures in especially vulnerable areas. Between 1999 and 2003, Wilbanks and his ORNL colleagues pioneered the idea of developing new climate change response strategies by integrating analyses of mitigation and adaptation. The result was an article for a special June 2007 issue of the international journal, Mitigation and Adaptation Strategies for Global Change, of which Wilbanks was one of three guest editors. Stating that "both mitigation and adaptation are needed in responding to risks of impacts from climate change," the article argues that mitigation "is essential in order to keep climate change impacts as low as possible" and that adaptation "is essential because impacts cannot be avoided." Both approaches offer alternatives. The article provides the example of "mitigation to reduce changes in precipitation patterns that would affect agriculture versus adaptive development of crop varieties resilient to a wider range of precipitation." More efficient, less expensive air conditioners could serve as both a mitigation and adaptation strategy by reducing electricity consumption for space cooling, especially if the electricity is produced by burning fossil fuels, and by making the appliances more affordable for lower-income consumers. Impacts on the energy sector In the past two years, Wilbanks led a team in assessing the effects of climate change on U.S. energy consumption, production and supply. The work was supported by the Department of Energy as a part of a series of reports by the U.S. Climate Change Science Program about climate change science. Reporting analyses that demand for interior cooling will rise 5-20% per 1°C increase in average temperatures and that demand for interior warming will fall 3-15% per 1°C rise in warming, the assessment emphasized that implications would vary by season and region, and that impacts would reflect differences in energy sources as well as total energy needs. Because electric fans and air conditioning deliver cooling, the team projected "increased demands for electricity, which is likely to affect planning by the electric utility industry." In regions with more severe climate change, energy production could be especially vulnerable to severe storms and water shortages. Hurricanes, expected to become more intense as oceans warm, can disrupt offshore oil and gas production. Hydroelectric power and nuclear power plant cooling require abundant water supplies that could be threatened by an annual reduction of snowfall in the Western mountains and episodic water shortages such as those currently plaguing the South and Midwest. Energy sector planners "have time available to consider strategies for adaptation to reduce possible negative impacts and take advantage of possible positive impacts," Wilbanks says. "The energy sector can incorporate climate change as an aspect of uncertainty and risk in longer-term strategic planning and investment." Impacts on communities
As a part of the Climate Change Science Program and with support from the U.S. Environmental Protection Agency, Wilbanks led another team considering possible impacts of climate change on cities and smaller communities. As with the energy sector, the study addressed the future sustainability of human systems in terms of vulnerabilities and risks. Under this approach, the research attempts to grapple with the societal impacts of climate change. The categories included population size and distribution, as well as ways in which sustained climate change might affect economic and technological institutions. As with ecosystems, the study suggests that vulnerabilities of cities and communities may vary widely according to a variety of characteristics, including location. Cities in coastal areas subject to severe storms and sea-level rise would experience challenges distinctly different from those in population centers in arid areas more vulnerable to water scarcity and fires. "While the potential for adaptation by American cities and developed nations to reduce their vulnerabilities is considerable, potentials for some densely populated cities of Asia and Africa are not as bright," Wilbanks says. Resilience An important new effort to understand and enhance the preparation of communities for environmental threats is the Community and Regional Resilience Initiative. The program is an outgrowth of the Southeast Regional Research Initiative, supported by the Department of Homeland Security and led by ORNL. The Laboratory's role is not an accident. "Oak Ridge is recognized nationally and internationally as a leader in conducting research on responses to climate change in collaboration with teams at other institutions," Wilbanks notes. Capitalizing on this reputation, ORNL helps cities think through the complicated issues that accompany emergency response plans on a large scale. As the program matures, Laboratory officials hope that years of studying climate and its impacts will translate into the ability to help communities adapt to what could be some of the most dramatic changes of the 21st century.—Carolyn Krause Contact: Thomas J. Wilbanks
|
 |
 |
 |
 |
 |
Web
site provided by Oak Ridge National Laboratory's Communications and
External Relations |
