How To Think About Climate Change

Some researchers say that climate change is one of the greatest threats facing mankind, and they call for drastic reductions in the greenhouse gases. Other researchers say that the science is weakly documented, warranting little more than further study. Some argue that greenhouse gas emissions can be decreased with net benefits to the economy, while others fear that it would severely damage productivity and incomes.

At this stage in the debate, substantial scientific evidence supports five basic points:

First, a body of several hundred distinguished scientists established by the United Nations has concluded that human activity is causing the change that they currently observe. This scientific body --Working Group I of the Intergovernmental Panel on Climate Change (IPCC) --recently stated in its summary for policymakers that, “The balance of evidence suggests a discernible human influence on global climate.” It is important to note that this opinion is not unanimous among scientists, and there have been complaints that dissenting views have not been adequately represented in the IPCC report. But the majority opinion has grown stronger over time, and the IPCC’s latest report reaches much firmer conclusions than its first one several years earlier.

Second, some degree of further climate change now seems to be inevitable. Even to stabilize emissions of the most common greenhouse gas--carbon dioxide--at present levels would require enormous cutbacks in emissions, on a scale that is probably unrealistic in the short to medium term.

Third, if this is correct, some adaptation to climate change is going to be necessary regardless of what else may be done to affect the future rate of change. It’s not a choice of whether to adapt or to follow other policies. Both will be required.

Fourth, damages from climate change could be serious, especially if the climate changes rapidly, but the severity of damage generally is difficult to predict.  Catastrophes are possible but unlikely;  adaptation to climate change could significantly reduce some, but now necessarily all, risks.

Fifth, some of the adverse effects of climate change may fall disproportionately on poor countries where adaptation capacity is more limited.

Here are several principles for thinking about the policy decisions ahead:

Think comprehensively about risks and costs. Climate change could affect human health, market goods

Think internationally. Rich and poor countries argue over how the burden of greenhouse gas emissions reductions should be allocated. However, no solution can be effective in the long term unless it ultimately leads to reductions in total global emissions, not just emissions in selected countries.

Think long-term. The risks of climate change extend over many decades and even centuries. To be effective, at least some actions must be taken in anticipation of long-term impacts, even before all the scientific evidence is clear. Our political system isn’t good in situations like that. But the long-term nature of the risks also means that we have time to hone our scientific understanding and policy responses over time. We don’t need to do everything right away.

Address adaptation. In areas like agriculture, managed forestry and human settlements, experience suggests that we have a medium-to-high ability to adapt to natural changes, given enough lead time and investment. Adjustments may be more difficult in other cases, for example in response to potential damage to natural ecosystems whose functions are not well understood. Improving the capacity to adapt where it is weak, as in many developing countries, may be one of the most effective ways to respond to some climate change risks.

Keep distributional issues in mind. The balancing of costs and risks concerns not just the world’s rich and poor today, but also the present generation and future ones. These are complex questions about which we know little and which require a mature political debate.

Estimate costs of emissions reduction realistically. Most people who have looked at this debate seem to agree that some low-cost improvements in energy efficiency can be made. However, it’s open to question whether these opportunities are substantial compared to, say, the amount of abatement needed to stabilize greenhouse gas emissions. With future worldwide demand for energy rising, the cost of longer-term reductions in emissions cannot help but rise in the absence of technical progress in non-fossil energy alternatives. The potential for such progress also needs to be assessed agricultural products, and non-market resources like wilderness areas and wetlands.  The cost of emissions policy may include distortions in employment, investment and innovation that are much larger than the out-of-pocket costs, but there also will be ancillary benefits of emissions reductions such as cleaner air.

The Clinton administration has stated that it will support legally binding emissions reductions in the international negotiations now under way. In January, the Administration issued a U.S. Draft Protocol Framework. Revised in June, it contains a number of policy ideas that could significantly enhance the cost-effectiveness of achieving reduction targets. These include emissions trading within the country and across borders. Developing countries would be encouraged to participate in several ways, and all countries would be required to invest in “climate-friendly technologies.” The U.S. proposal calls for all industrialized countries to reduce their emissions by a common percentage, but this idea is hotly opposed by some of them.

One weakness of this draft is that it does little to address adaptation. This reflects a broader weakness in the Framework Convention, which views adaptation as a concern for individual countries. The subject deserves greater prominence in the debate over climate policies.