Читать книгу The Economics of Climate Change: a Primer - The Congressional Budget Office - Страница 6

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The atmosphere and climate are part of the stock of natural resources available to people to satisfy their needs and wants over time. From an economic point of view, climate policy involves measuring and comparing the values that people place on resources, across alternative uses and at different points in time, and applying the results to choose a course of action. An effective policy would balance the benefits and costs of using the atmosphere and distribute those benefits and costs among people in an acceptable way.

Uncertainty about the scientific aspects of climate change and about its potential effects complicates the challenge of developing policy by making it difficult to estimate or balance the costs of restricting greenhouse gas emissions and the benefits of averting climate change. (Some of the risks involved, moreover, may be effectively impossible to evaluate or balance in pecuniary terms.) Nevertheless, assessments of the potential costs and benefits of a warming climate typically conclude that the continued growth of emissions could ultimately cause extensive physical and economic damage. Many studies indicate significant benefits from undertaking research to better understand the processes and economic effects of climate change and to discover and develop new and better technologies to reduce or eliminate greenhouse gas emissions.

At the same time, such studies typically find relatively small net benefits from acting to reduce greenhouse gas emissions in the near term. In balancing alternative investments, they conclude that if modest restrictions on emissions were implemented today, they would yield net benefits in the future; however, more-extensive restrictions would crowd out other types of investment, reducing the rate of economic growth and affecting current and future generations’ material prosperity even more than the averted change would. As income and wealth grow and technology improves, the studies say, future generations are likely to find it easier to adapt to the effects of a changing climate and to gradually impose increasingly strict restraints on emissions to avoid further alteration.

Those conclusions greatly depend, among other things, on how one balances the welfare of current generations against that of future generations. In assessments of costs and benefits occurring at different points in time, that process of weighting is typically achieved by using an interest, or discount, rate to convert future values to present ones. But there is little agreement about how to discount costs and benefits over the long time horizons involved in analyzing climate change.

Whatever weighting scheme is chosen, consistency calls for applying it to all long-term investment alternatives. For example, applying a lower discount rate to give more weight to the welfare of future generations implies that society should reduce its current consumption and increase its overall rate of investment in productive physical and human capital of all kinds—not only those involved in ensuring a beneficial future climate.

Government policies that deal with use of the atmosphere inevitably affect the distribution of resources. Inaction benefits people who are alive today while potentially harming future generations. Reducing emissions now may benefit future generations while imposing costs on the current population and may benefit countries at relatively higher risk of adverse effects from warming while hurting those that stand to gain from it. Restraints on emissions would impose costs on nearly everyone in the global economy, but they would affect energy-producing and energy-intensive industries, regions, and countries much more than they would others. However, many studies of the costs and benefits of climate change fail to highlight the extent to which differences in geographic and economic circumstances complicate the balancing of interests.