Showing papers by "Gary W. Yohe published in 2007"

The weakest link hypothesis for adaptive capacity: An empirical test

Abstract: Yohe and Tol (2001) built an indexing method for vulnerability based on the hypothesis that the adaptive capacity for any system facing a vector of external stresses could be explained by the weakest of eight underlying determinants – the so-called “weakest link” hypothesis. Subsequent work supported the hypothesis by analogy from other contexts, but we now offer perhaps the first attempt to explore its validity through empirical means. We estimate a structural form designed to accommodate the full range of possible interactions across determinants. The perfect complement case of the pure “weakest-link” formulation lies on one extreme, and the perfect substitute case where each determinant can compensate for all others at constant rates is the other limiting case. For vulnerability to natural disasters, infant mortality and drinking water treatment, we find qualified support for a modified weakest link hypothesis: the weakest indicator plays an important role, but is not essential because other factors can compensate (with increasing difficulty). For life expectancy, sanitation and nutrition, we find a relationship that is close to linear – the perfect substitute case where the various determinants of adaptive capacity can compensate for each other. Moreover, we find another source of diversity in the assessment of vulnerability, since the factors from which systems draw to create adaptive capacity are different for different risks.

Infectious disease, development, and climate change, A scenario analysis

Abstract: We study the effects of development and climate change on infectious diseases in Sub-Saharan Africa. Infant mortality and infectious disease are closely related, but there are better data for the former. In an international cross-section, per capita income, literacy, and absolute poverty significantly affect infant mortality. We use scenarios of these three determinants and of climate change to project the future incidence of malaria, assuming it to change proportionally to infant mortality. Malaria deaths will first increase, because of population growth and climate change, but then fall, because of development. This pattern is robust to the choice of scenario, parameters, and starting conditions; and it holds for diarrhoea, schistosomiasis, and dengue fever as well. However, the timing and level of the mortality peak is very sensitive to assumptions. Climate change is important in the medium term, but dominated in the long term by development. As climate can only be changed with a substantial delay, development is the preferred strategy to reduce infectious diseases even if they are exacerbated by climate change. Development can, in particular, support the needed strengthening of disease control programs in the short run and thereby increase the capacity to cope with projected increases in infectious diseases over the medium to long term. This conclusion must, however, be viewed with caution,

Infinite uncertainty, forgotten feedbacks, and cost-benefit analysis of climate policy

Abstract: Tol (2003) questioned the applicability of expected cost-benefit analysis to global mitigation policy when he found evidence that the uncertainty surrounding estimates of the marginal damage of climate change could be infinite even if total damages were finite. Yohe (2003) suggested that this problem could be alleviated if international development aid were directed at eliminating the source of the problem - climate induced negative growth rates in a few regions along a handful of troublesome scenarios. The hypothesis about adding a second policy lever to the climate policy calculus is shown to hold, though perhaps not as robustly as originally thought. A portfolio of international policies with at least two independent tools can avoid infinite uncertainty on the margins and the associated implications for global mitigation policy at a reasonable price even in the relatively unlikely event that climate change causes negative economic growth in a region or two.

Adaptation and mitigation as complementary tools for reducing the risk of climate impacts

Abstract: This paper uses the likelihood of flooding along Brahmaputra and Ganges Rivers in India to explore the hypothesis that adaptation and mitigation can be viewed as complements rather than sustitutes. For futures where climate change will produce smooth, monotonic and manageable effects, adopting a mitigation strategy is shown to increase the ability of adaptation to reduce the likelihood of crossing critical threshold of tolerable climate. For futures where climate change will produce variable impacts overtime, though, it is possible that mitigation will make adaptation less productive for some time intervals. In cases of exaggerated climate change, adaptation may fail entirely regardless of how much mitigation is applied. Judging the degree of complementarity is therefore an empirical question because the relative efficacy of adaptation is site specific and path dependent. It follows that delibrations over climate policy should rely more on detailed analyses of how the distributions of possible impacts of climate might change over space and time.

The stern review : Implications for climate change

Abstract: ISSN: 0013-9157 (Print) 1939-9154 (Online) Journal homepage: http://www.tandfonline.com/loi/venv20 The Stern Review: Implications for Climate Change Gary W. Yohe & Richard S. J. Tol To cite this article: Gary W. Yohe & Richard S. J. Tol (2007) The Stern Review: Implications for Climate Change, Environment: Science and Policy for Sustainable Development, 49:2, 36-43, DOI: 10.3200/ENVT.49.2.36-43 To link to this article: https://doi.org/10.3200/ENVT.49.2.36-43

On Setting Near-Term Climate Policy While the Dust Begins to Settle: The Legacy of the Stern Review

Abstract: We review the explosion of commentary that has followed the release of the Stern Review: The Economics of Climate Change, and agree with most of what has been written. The Review is right when it argues on economic grounds for immediate intervention to reduce emissions of greenhouse gases, but we feel that it is right for the wrong reasons. A persuasive case can be made that climate risks are real and increasingly threatening. If follows that some sort of policy will be required, and the least cost approach necessarily involves starting now. Since policy implemented in 2007 will not "solve" the climate problem, near term interventions can be designed to begin the process by working to avoid locking in high. carbon investments and providing adequate incentives for carbon sequestration. We argue that both objectives can be achieved without undue economic harm in the near term by pricing carbon at something on the order of $15 per ton as long as it is understood that the price will increase persistently and predictably at something like the rate of interest; and we express support for a tax, alternative to the usual cap-and-trade approach.

Precaution And A Dismal Theorem: Implications For Climate Policy And Climate Research

Abstract: We discuss the implication of Weitzman's Dismal Theorem for climate policy and climate research.

Climate change : pro-poor adaptation, risk management, and mitigation strategies

Abstract: Climate change results from an increased concentration of greenhouse gases like carbon dioxide, nitrous oxide, and methane associated with economic activities, including energy, industry, transport, and land use patterns. Rich countries emit the majority of these gases, while poor countries are more vulnerable to their negative effects. Further, developing countries are more vulnerable and less able to adapt to these changing climatic conditions because of their locations; greater dependence on agriculture and natural resources; larger variations in weather and temperature conditions; and lower availability of critical resources like water, land, production inputs, capital, and public services. The inability of developing countries to respond and act immediately to lessen the impacts of climate change will have serious global economic consequences. Appropriate climate change policies, if adopted now, can stimulate pro-poor investment. More specifically, they can increase the profitability of environmentally sustainable practices even as they generate income for small producers and investment flows for rural communities. Climate mitigation through carbon offsets and carbon trading can increase income in rural areas in developing countries, directly improving livelihoods while enhancing adaptive capacity. In its recently released fourth assessment report, the Intergovernmental Panel on Climate Change concluded that a portfolio of both adaptation and mitigation will be required. This brief supports this conclusion as it explores pro-poor adaptation, risk management, and mitigation strategies in response to climate change.

Thoughts on "The Social Cost of Carbon: Trends, Outliers and Catastrophes"

Abstract: The updated meta-analysis of estimates of the social cost of carbon (SCC) offered by Tol (2007) is a welcome addition to the conversations about “What is new?” and “What should we do with so much uncertainty?” It offers five conclusions with diminishing persuasion; but perhaps its largest contribution is its differentiating list of the 211 estimates that can now be found in the literature. Simply compiling, segregating, and referencing this list is worthy of commendation for those who try to bring the social cost of carbon to bear on issues of climate policy. That point made, though, it is important to respond to his remaining four conclusions:

The stern review: a deconstruction

Abstract: Using a simple model designed for transparency but nonetheless calibrated to support the much-quoted damage estimates of the Stern Review of the Economics of Climate Change, we demonstrate significant sensitivity of those results to assumptions about the pure rate of time preference, the discounting time horizon, rates of risk and equity aversion used to compute certainty- and equity equivalent annuities, and presumed static regional vulnerability. Manipulation of any of these parameters one at a time across reasonable ranges can diminish damage estimates by as much as 84% or, in the case of extending the time horizon, increase damage estimates by 900%. We also confirm the usual result that limiting atmospheric concentrations to specific benchmarks above 400 ppm cannot eliminate damages. Nonetheless, we applaud the Stern Review author team for reconfirming that the climate problem can productively be approached as an economic problem whose solutions can be explored with the tools of decision analysis.