Climate Change: The Moral Choices

The effects of global warming will persist for hundreds of years. What are our responsibilities and duties today to help safeguard the distant future? That is the question ethicists are now asking.

illustration of couple lying on stark beach with smoke stack in background

One of the defining characteristics of climate change is poorly appreciated by most people: the higher temperatures and other effects induced by increasing levels of carbon dioxide in the atmosphere will persist for a very long time. Scientists have long realized that carbon dioxide emitted during the burning of fossil fuels tends to linger in the atmosphere for extended periods, even for centuries. Over the last few years, researchers have calculated that some of the resulting changes to the earth’s climate, including increased temperature, are more persistent still: even if emissions are abruptly ended and carbon dioxide levels gradually drop, the temperature will stubbornly remain elevated for a thousand years or more. The earth’s thermostat is essentially being turned up and there are no readily foreseeable ways to turn it back down; even risky geoengineering schemes would at best offset the higher temperatures only temporarily.

It’s a shocking realization, especially given how little progress has been made in slowing carbon dioxide emissions. But it is precisely the long-term nature of the problem that makes it so urgent for us to limit emissions as quickly and radically as possible. To have a decent chance of meeting the widely accepted international goal of keeping warming at or below 2 °C, emissions need to be cut substantially over the next few years. By 2050 they must be reduced by half or more from 2009 levels.

The mismatch between when we need to act and when many of the benefits will accrue helps to explain why climate change is such a politically and economically thorny problem. How do you convince people and governments to invest in a far-off future? Clearly, it is not a problem that can easily be addressed by most politicians, given the immediate and pressing needs of their constituents. Because it involves defining and understanding our responsibilities to future generations, our action (or inaction) on climate change falls squarely into the realm of moral and political philosophy.

Over the last few years a small but growing number of writers have begun to wrestle with some profound questions. What ethical guidelines should economists follow when evaluating today’s costs against future benefits? How should we weigh uncertainties, including the risks of catastrophic changes wrought by global warming? Would geoengineering be ethical? How does climate change affect our perception of the world and our future role in it? The conclusions they’ve reached are nuanced and can turn on esoteric definitions of terms such as “justice” and “moral good.” But their reasoning often provides keen insights into today’s most pressing policy questions.