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Climate Change, Mortality, and Adaptation: Evidence from Annual Fluctuations in Weather in the US

This paper produces the first large-scale estimates of the U.S. health related welfare costs due to climate change. Using the presumably random year-to-year variation in temperature and two state of the art climate models, the analysis suggests that under a "business as usual" scenario climate change will lead to an increase in the overall U.S. annual mortality rate ranging from 0.5% to 1.7% by the end of the 21st century. These overall estimates are statistically indistinguishable from zero, although there is evidence of statistically significant increases in mortality rates for some subpopulations, particularly infants. As the canonical Becker-Grossman health production function model highlights, the full welfare impact will be reflected in health outcomes and increased consumption of goods that preserve individuals' health. Individuals' likely first compensatory response is increased use of air conditioning; the analysis indicates that climate change would increase U.S. annual residential energy consumption by a statistically significant 15% to 30% ($15 to $35 billion in 2006 dollars) at the end of the century. It seems reasonable to assume that the mortality impacts would be larger without the increased energy consumption. Further, the estimated mortality and energy impacts likely overstate the long-run impacts on these outcomes, since individuals can engage in a wider set of adaptations in the longer run to mitigate costs. Overall, the analysis suggests that the health related welfare costs of higher temperatures due to climate change are likely to be quite modest in the U.S.

Climate Change: A Political Quagmire?

Climate change is a complex science and technology-related issue that will have profound effects on developing and industrial countries alike, and is a central policy issue for all societies. The lecture reviews the scientific situation and the current state of the negotiations to provide an appreciation of the phenomenon and of the response to date of the international community. A more political analysis of the climate change issue is also presented, including why the issue is in many respects entirely unique, and why the US political system is not able, yet, to mount an adequate reply. Finally, some musings about what might have been and what the future is likely to hold.

A transcript of the lecture is provided.

Climate change: comparative impact on developing and developed countries

Government organizations are responsible for strategic decisions regarding the economic development of individual countries and regional areas. This decision-making process is influenced by the certainty of the information presented to government officials. One area where this decision-making influence is challenging government officials is in climate-based events. The past decade has witnessed a significant rise in the number of climate events, as well as the number of people affected by climate events. Far from being under control, evidence and long-term projections suggest that these events are climate-based rather than weather-based. In these projections, climate change is a global issue with potential impacts for every country. However, the relative impact of these events will be far different in the developed and developing worlds. As detailed in this paper, the authors examined this disparity through an analysis of 10 countries with varying income levels to determine the relative impact of climate change in the context of a single infrastructure element, paved and unpaved roads. Using the latest global climate models combined with economic and infrastructure data, the study highlights the disparity of opportunity costs between high- and low-income countries. Roads are a key element in enabling developing economy communities to have access to basic services, generate an income through agriculture and gain productive employment. The potential for road damage and the inability to invest in new road infrastructure could impact the economic stability of communities. The paper provides a quantitative introduction to these issues and the challenges presented to government organizations when considering the long-term effects of climate change.

Climate Change: Comparative Impact on Developing and Developed Countries

Government organizations are responsible for strategic decisions regarding the economic development of individual countries and regional areas. This decision-making process is influenced by the certainty of the information presented to government officials. One area where this decision-making influence is challenging government officials is in climate-based events. The past decade has witnessed a significant rise in the number of climate events, as well as the number of people affected by climate events. Far from being under control, evidence and long-term projections suggest that these events are climate-based rather than weather-based. In these projections, climate change is a global issue with potential impacts for every country. However, the relative impact of these events will be far different in the developed and developing worlds. As detailed in this paper, the authors examined this disparity through an analysis of 10 countries with varying income levels to determine the relative impact of climate change in the context of a single infrastructure element, paved and unpaved roads. Using the latest global climate models combined with economic and infrastructure data, the study highlights the disparity of opportunity costs between high- and low-income countries. Roads are a key element in enabling developing economy communities to have access to basic services, generate an income through agriculture and gain productive employment. The potential for road damage and the inability to invest in new road infrastructure could impact the economic stability of communities. The paper provides a quantitative introduction to these issues and the challenges presented to government organizations when considering the long-term effects of climate change.

© 2011 Taylor & Francis Group

Climate change: State of the science and implications for policy

Prof. Prinn, co-director of the MIT Global Change Joint Program, provides a brief overview of the definition of climate, the reality of the greenhouse effect, and how reliable the forecasts of future climate are. He then discusses why the detection of the human influence on climate is so difficult, and addresses certain areas of the scientific research especially important for informing policymaking. Finally, he argues that because the science is both uncertain and evolving, scientists should be in much closer contact with the policy development process than they are at present.

(Hearing summary)

Climate effects of seasonally varying Biomass Burning emitted Carbonaceous Aerosols (BBCA)

The climate impact of the seasonality of Biomass Burning emitted Carbonaceous Aerosols (BBCA) is studied using an aerosol-climate model coupled with a slab ocean model in a set of 60-year long simulations, driven by BBCA emission data with and without seasonal variation, respectively. The model run with seasonally varying emission of BBCA leads to an increase in the external mixture of carbonaceous aerosols as well as in the internal mixture of organic carbon and sulfate but a decrease in the internal mixture of black carbon and sulfate relative to those in the run with constant annual BBCA emissions, as a result of different strengths of source/sink processes. The differences in atmospheric direct radiative forcing (DRF) caused by BBCA seasonality are in phase with the differences in column concentrations of the external mixture of carbonaceous aerosols in space and time. In contrast, the differences in all-sky radiative forcing at the top of the atmosphere and at the earth's surface extend beyond the BBCA source regions due to climate feedback through cloud distribution and precipitation. The seasonality of biomass burning emissions uniquely affects the global distributions of convective clouds and precipitation, indicating that these emissions have an impact on atmospheric circulation. In addition, the climate response to the periodic climate forcing of BBCA is not limited to biomass burning seasons but dynamically extends into non-biomass burning seasons as well.

Climate effects of seasonally varying Biomass Burning emitted Carbonaceous Aerosols (BBCA)

The climate impact of the seasonality of Biomass Burning emitted Carbonaceous Aerosols (BBCA) is studied using an aerosol-climate model coupled with a slab ocean model in a set of 60-year long simulations, driven by BBCA emission data with and without seasonal variation, respectively. The model run with seasonally varying emission of BBCA leads to an increase in the external mixture of carbonaceous aerosols as well as in the internal mixture of organic carbon and sulfate but a decrease in the internal mixture of black carbon and sulfate relative to those in the run with constant annual BBCA emissions, as a result of different strengths of source/sink processes. The differences in atmospheric direct radiative forcing (DRF) caused by BBCA seasonality are in phase with the differences in column concentrations of the external mixture of carbonaceous aerosols in space and time. In contrast, the differences in all-sky radiative forcing at the top of the atmosphere and at the earth's surface extend beyond the BBCA source regions due to climate feedback through cloud distribution and precipitation. The seasonality of biomass burning emissions uniquely affects the global distributions of convective clouds and precipitation, indicating that these emissions have an impact on atmospheric circulation. In addition, the climate response to the periodic climate forcing of BBCA is not limited to biomass burning seasons but dynamically extends into non-biomass burning seasons as well.

Climate Favela: A Comment on Barrett

About the book: With increasing greenhouse gas emissions, we are embarked on an unprecedented experiment with an uncertain outcome for the future of the planet. The Kyoto Protocol serves as an initial step through 2012 to mitigate the threats posed by global climate change. A second step is needed, and policy-makers, scholars, business people, and environmentalists have begun debating the structure of the successor to the Kyoto agreement. Written by a team of leading scholars in economics, law, and international relations, this book contributes to this debate by examining the merits of six alternative international architectures for global climate policy. Architectures for Agreement offers the reader a uniquely wide-ranging menu of options for post-Kyoto climate policy, with a concern throughout to learn from past experience in order to maximize opportunities for future success in the real, ‘second-best’ world.

Climate impact of carbonaceous and sulfate aerosols in an interactive size-resolving aerosol-climate model

A multi-mode, two-moment aerosol model has been incorporated in the NCAR CAM3.0 to study the impact of anthropogenic aerosols on the global climate system. Seven aerosol modes, namely three sulfate, one external black carbon, one primary organic carbon, one sulfate/black carbon mixed mode and one sulfate/organic carbon mixed mode, are included in the model. Each aerosol mode predicts both number and mass concentration and thus aerosol size distribution which is critical to aerosol microphysics and optical property. When aerosols are assumed to be internally mixed, their chemical and optical properties are different than when they are externally mixed. Model results suggest that the major portions of black carbon and sulfate masses exist as mixed aerosols while two thirds of organic carbon mass is also in mixed form. In this study, multiple 60-year long simulations are carried out to examine the impact of the carbonaceous and sulfate aerosols in the climate system. Strong positive atmospheric forcing and negative surface forcing by the mixed aerosols affect the atmospheric thermal structure and consequently alter values of important parameters including cloud cover, height of planetary boundary layer, surface heat fluxes, and precipitation.

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