Adapting to Climate Change

• Author: Peter S. Heller and Muthukumara Mani
• Position: Deputy Director of the IMF's Fiscal Affairs Department/Economist in the IMF's Fiscal Affairs Department

Not much talked about but still worrisome are the economic and fiscal disruptions likely to be caused by global climate change, especially for developing countries. Policymakers should take steps to minimize these disruptions, and sooner rather than later.

After decades of debate, global warming is now recognized as inevitable, with its impact likely to be felt for centuries to come. Even the most conservative forecasts suggest that the Earth's climate is already warming at a pace that is without precedent over the last ten thousand years. Although there remains considerable uncertainty on the pace, magnitude, and regional distribution of the changes that can be anticipated over the next century, the need for policy actions to mitigate the sources of global warming is generally accepted (see box).

Heating up

Surface temperature measurements recorded daily at hundreds of locations over the last 100 years indicate that the Earth's surface has warmed by about 1 degree Fahrenheit during that time. Warming has been particularly strong during the last 20 years and has been substantially greater than the average rate of warming in the twentieth century. It has been accompanied by retreating glaciers, thinning arctic ice, rising sea levels, lengthened growing seasons for some crops, and earlier arrivals of migratory birds. Based on assumptions that emissions of greenhouse gases will accelerate and conservative assumptions about the reaction of the climate, computer models suggest that average global surface temperatures will rise between 2.5 and 10.4 degrees Fahrenheit (1.4 and 5.8 degrees Celsius) by the end of the twenty-first century. While there is uncertainty, a minimum change can at least be expected within the forecast ranges. Continued vigilance and monitoring are necessary, because they might decrease the uncertainty and allow for more accurate forecasts.

The focus thus far has been on what the industrial nations should do, given their responsibility for the present concentration of greenhouse gases. In the Kyoto Protocol, adopted in December 1997, the industrial nations agreed to limit emissions of these gases relative to the levels of 1990. The role of the developing countries in these mitigation efforts is still being debated, and the outcome of this debate will be critical, given the rapid growth of their greenhouse gas emissions.

But far less attention has been paid to what developing countries should do to adapt to the consequences of climate change. This is particularly worrisome because climate change affects both poverty and development. Much of its impact is likely to be borne by the rural poor in the tropics and subtropics, whose capacity to cope is extremely limited. Even the smallest temperature increase in these areas would lower agricultural productivity. If this happens, malnutrition will become more prevalent and water will become scarcer in many areas-increasing the incidence of diseases that are vector borne (for example, malaria and dengue fever) and water borne (for example, cholera). Rising sea levels could displace tens of millions of people in...