Last week, the United Nations Intergovernmental Panel on Climate Change released its Sixth Assessment Report on the science of global climate change. The report reaffirms that human activity, and the burning of fossil fuels in particular, has contributed to an increase in global mean temperatures, and summarizes the growing evidence that this warming is having observable effects across the globe, including an increase in heat waves and changes in precipitation patterns.
Somewhat more controversially, the IPCC report outlines a range of potential scenarios for future climate change, some of which are more likely than others. Such scenarios are necessarily somewhat speculative, as they rely upon a range of assumptions about population, economic growth, future emissions, and climate sensitivity to further accumulations of greenhouse gases. Some of these future scenarios are grimmer than others, but all include unwelcome changes for much of the world. Even in the report’s most optimistic scenario, which involves greenhouse gas levels declining after 2050, the report projects a rise in the planetary temperature, increased rainfall, and higher sea levels by 2100. Overall, the report backs away from some of the more extreme scenarios offered in prior IPCC reports, but reaffirms that the accumulation of greenhouse gases in the atmosphere presents significant risks of economic and environmental disruption, particularly in those parts of the world least capable of adapting to such changes.
As long ago become standard with the release of every IPCC report, commentators on the political right have been dismissive of the new report. Some have characterized it as yet another example of ecological doomsaying. Others have suggested that insofar as some of the more extreme temperature projections have been deemed less likely, this is reason to relax. Such responses miss the point and misunderstand the nature of the climate challenge. Neither a low likelihood of extreme outcomes nor residual uncertainty about the likely consequences of climate change justifies inaction.
It is fair to note that computer models cannot predict the precise consequences of increasing concentrations of greenhouse gas emissions globally, let alone on the regional level. Fortunately, the IPCC does not rely exclusively on such models. A wealth of research on current and past climate conditions demonstrate that climate change is real, that humans are contributing to these changes, and that these changes pose serious risks.
Even if one believes the likelihood of catastrophic climate change is small, the consequences are sufficiently grave to justify prudent measures to reduce the likelihood and magnitude of adverse events. You don’t install smoke alarms, acquire fire extinguishers, and buy home insurance because you expect a house fire. Rather, you recognize the value of insuring against low-probability/high-magnitude events. The costs and dislocation resulting from your house burning down are sufficiently grave that they justify prudent investments that will reduce the likelihood and the consequences of such an event.
A similar logic applies to many larger risks that require collective action, as conservatives have been willing to recognize in other contexts. During the Cold War, for example, conservatives supported significant defense spending not because Soviet aggression was certain, but because even a low-likelihood conflict could have disastrous consequences. Accordingly, national security policy combined measures that would make the likelihood of a confrontation with the USSR both less likely and less severe.
Thus even if one believes that cataclysmic climate change is unlikely, this does not justify a do-nothing response. The question is not whether climate policies are necessary. Rather the question is which policy responses can be justified as prudent, cost-effective ways to reduce the magnitude of potential warming, the likelihood of adverse consequences, or both. In other words, what sorts of prudent steps can be taken to reduce the accumulation of greenhouse gases in the atmosphere so as to reduce the amount of warming (mitigation) as well as to reduce the negative consequences such warming may bring (adaptation).
Many policies to increase the development and deployment of carbon-reducing technologies can be justified as prudent measures to address the threats posed by climate change, including the elimination of fossil fuel subsidies, the removal of regulatory and other barriers to the development and deployment of carbon-reducing technologies, and reforms to federal R&D programs to accelerate and further incentivize clean energy research (such as through prizes).
A carbon tax, so as to increase the marginal incentive to reduce carbon intensity and transition away from carbon-based fuels, would also qualify, particularly if the revenues were rebated on a per-capita basis so as to reduce the tax’s likely regressive and economy-suppressing impacts. The Climate Leadership Council outlined the particulars of one such carbon tax proposal here. The aim of such a tax is to put a price on carbon emissions, not to fill federal coffers or expand governmental control of private economic decisions.
Many conventional regulatory measures, on the other hand, are difficult to justify on this basis, either because they are too costly, do too little to reduce emissions (and do it too slowly), hamstring technological development, or would fail to produce gains that could be replicated across the globe (an important consideration because climate change is a global problem). International agreements may make for good symbolism, but they are no substitute for serious climate policy. Accepting the seriousness of climate change does not require accepting the progressive policy playbook. To the contrary, taking climate change seriously calls for alternative (and more conservative) approaches.
Reasonable people can of course disagree on which policies represent responsible responses to the threats posed by climate change, and political realities may constrain the range of viable policy choices. But the policy debate should focus on which combination of measures makes the most sense, not whether climate change is a serious policy concern, and conservatives need to be part of this debate.
The latest IPCC report provided greater clarity about the nature of the climate challenge, but significant uncertainty remains. That is the nature of the problem. But such residual uncertainty does not justify inaction. Doing nothing about climate change is neither responsible nor prudent.