Strategies for Adapting to the Greenhouse Effect
Strategies for Adapting to the Greenhouse Effect (available as either html or PDF, 17 pp., 1.3 MB,) was originally published in the Journal of the American Planning Association, Summer:311-323 (1990). The report's Summary, Introduction and conclusion, Planning for the Long Run, are available below.
For additional reports focused on the implications of rising sea level, go to More Sea Level Rise Reports.
Increasing concentrations of CO2 and other gases seem likely to warm the earth in the next century. We examine opportunities to prepare for the consequences, focussing on options that are rational even if one is skeptical about global warming. Some responses can be postponed. But many low-cost opportunities will slip away if we fail to act; and reaching a consensus on what is fair is easier when the consequences seem remote. We conclude that some changes in land use and water allocation should be implemented today, even if effective dates are several decades in the future.
In the last three decades, a scientific consensus has emerged that humanity is gradually setting in motion a global warming by a mechanism commonly known as the "greenhouse effect." If current trends continue, our planet is likely to warm 3-5°C in the next century - as much as it has warmed since the last ice age. Such a warming would raise sea level a meter or more, and threaten water supplies, forests, and agriculture in many parts of the world. In response, the U.N. General Assembly has created an Intergovernmental Panel on Climate Change to develop a plan for decreasing worldwide emissions. However, climatologists have generally concluded that it is too late to prevent a one or two degree warming.
Should planners begin to prepare for the consequences of the greenhouse effect? The need to respond today depends on (1) the likelihood of global warming; (2) the magnitude of the impacts; and (3) the potential for anticipatory measures to reduce adverse impacts if sea level rises or climate changes as expected, without imposing substantial costs if the changes do not unfold. Although the literature on the first two factors is extensive, the latter issue has rarely been mentioned. As a result, some people assume that it would be unwise to prepare for global warming until its eventuality and consequences are firmly established.
In this article, we show that for many of the possible consequences of global warming, one can develop anticipatory responses that would substantially reduce adverse impacts of global warming with relatively little risk of the response proving to be ill-advised should the expected effects of global warming fail to unfold. After briefly summarizing the literature on the causes and effects of global warming, we suggest a number of criteria for evaluating response strategies, and present several example responses in detail. Although most of the examples involve the United States, similar opportunities are available in other countries. We hope that this article helps motivate planners throughout the world to begin preparing for the uncertain consequences of a global warming.
History offers few examples in which society undertook actions for the sole purpose of heading off a problem that was not expected for decades or centuries. Yet the Thames River Barrier, the U.S. Constitution, and international efforts to control world population illustrate that people can plan for the very long run when a present-day crisis puts an issue on the table. Once the public decides that it wants a problem solved, it is almost always willing to pay the extra cost of ensuring that the solutions do more than merely delay the day of reckoning.
The worldwide reaction to recent warm years suggests that there may soon be a public consensus to solve the problems associated with the greenhouse effect. But unless planners begin preparing rational responses, politicians will not know what to do when they are ready to act. In some cases they may be willing to commission studies and wait. But they are just as likely to act (or not act) based on whatever options are available at the time. Even if better options are discovered later, there is no guarantee that there will be a public outcry to revisit the issue.
The example responses we have outlined suggests that for most problems, one can envision a number of easy solutions that would at least begin to address the problem without arousing a constituency in opposition or subsequently appearing to be ill-advised. The examples also suggest that in many cases, the more costly options necessary to solve the whole problem would still prove to be good investments even if the climate does not change as expected.
Because of the severity of the potential impacts, it is completely appropriate for policy makers and the public to focus primarily on measures to limit the extent to which humanity raises the earth's temperature in the years ahead, an issue outside the domain of most planners. Nevertheless, past and current emissions suggest that it is too late to completely prevent a change in climate, so we will have to learn to live with the consequences. Although planners are sometimes frustrated by the futility of focussing politicians' attention on events beyond the next election, global warming may be an opportunity to help them show the voters that they are thinking about the type of world we pass on to future generations. But whether the politicians lead or follow, they public will have to decide the type of world we plan to achieve: if something has to give, should our priority be to maintain current patterns of land and resource use, to avoid tax increases, or to protect the environment?
Strategies for Adapting to the Greenhouse Effect (PDF, 17 pp., 1.3 MB, was originally published in the Journal of the American Planning Association, Summer:311-323 (1990).