08/12/2008 05:12 am ET | Updated May 25, 2011

How Scary is Climate Change?

Could climate change be crowding out more important environmental issues from the international policy agenda? While climate change is surely an important issue, it may not warrant such an elevated position.

Climate change is widely hailed as the most pressing global environmental threat. The issue resonates widely, when everyone claims to sense higher summer temperatures than their memories of years past. When US presidential candidates talk about international environmental issues they focus almost exclusively on climate change. The majority of US support for applied and basic research in both the hard and social sciences on the international environment has gone to climate change related issues. The overwhelming majority of the world's political energy over the last decade has also gone to addressing this issue.

Do we know if climate change is the most pressing global environmental threat? It might be, but are we so sure that we are confident about neglecting other pressing threats? How can such determinations even be made?

A reasonable assessment of the most urgent global environmental threats warranting collective action requires answering most of the following questions:
• How many people are likely to be affected by the problem?
• What is the net discounted economic cost of dealing with the problem?
• When will the effects occur?
• What is the likelihood of significant threats?
• Are the changes likely to be irreversible?
• What realistic policy options are available to mitigate the effects or to adapt to them?
• What is the political likelihood of successfully mobilizing meaningful international political action around the issue?

There is scientific consensus about the rough magnitude of the environmental damage 40 years from now. Average global temperatures will be higher, sea levels will be higher, there will be more extreme storms, and there will be regional effects on agriculture.

But there is much more uncertainty on the other questions. When will the effects be noticeable? Is it cost-effective to prevent them? Is it possible to prioritize the mitigation and adaptation options? Given the lack of clarity in our ability to answer these questions, we must ask if dealing with climate change is more urgent than many other topics on the international environmental agenda.

For instance, water quality in developing countries, protecting ecosystems, halting the loss of biodiversity, and reducing the release of toxic chemicals are surely plausible candidates for more attention. For instance, while estimates of the cost of dealing with climate change run in the trillions of dollars, the UN estimated that millions of third world children can soon be saved from waterborne diseases at an annual cost of roughly 1 billion dollars for water sanitation.
In addition to the technical assessments of environmental priorities, climate change may also be the hardest issue to address politically at the international level. Mobilizing meaningful action through multilateral diplomacy, while highly successful in dealing with as stratospheric ozone depletion, European acid rain and marine pollution, is extremely difficult for climate change. The core political reality is that the likely short to medium term victims from climate change are the Global South, which lacks meaningful political clout at the international level, whereas those who are asked to make meaningful short to medium term (and possibly highly expensive) policy changes are the more influential global North. Thus those with the most political capacity for dealing with climate change are some of the most reluctant to make meaningful short term commitments.

Unfortunately, fixing climate change does not also repair other environmental quality issues. There is no silver bullet. Conversely, concerted progress across a host of international environmental issues could accelerate technological changes to help reduce greenhouse gas emissions and foster political support from the private sector for harmonized international standards.

Before continuing to sink scarce political capital into the climate change issue, we should be confident that climate change is indeed more important than all other issues that have received attention over the last 30 or more years.