Climate risks in the 21st century

By Kent on December 26, 2007 11:13 AM | Permalink | Comments (0) | TrackBacks (0) | View blog reactions

Although 169 nations have ratified the Kyoto Protocol to reduce GHG emissions, the world's largest emitter, the United States, has rejected the treaty, and the world's two most populous nations, China and India, remain under no emissions constraints. Gaining wider international participation in future climate treaties remains a vexing challenge for international climate policy. Climate change presents a classic collective action problem because nations who choose to reduce their emissions are able neither to directly capture the benefits of those reductions nor to limit benefits to their own citizens. As a result, international treaties are open to serious temptations for "free riding" by some nations on the emissions reductions of others, leading to a call for binding emissions limits over time for all nations. However, agreement on such binding limits may well require a greater understanding of how the costs and benefits of climate change are likely to vary between nations. (Difenbaugh, N. S., F. Giorgi, L. Raymond, and X. Bi. 2007. Indicators of 21st century socioclimatic exposure Proceedings of the National Academy of Sciences USA 104:20195-20198.; subscription required)

The paper by Noah Diffengaugh and his colleagues appeared online on the 10th of December, one week after the opening of the United Nations Climate Change Conference in Bali. As we all know by now, an American delegate was booed at the conference, and a delegate from Papua New Guinea received thunderous applause¹ when he said “If for some reason you are not willing to lead, leave it to the rest of us. Please – get out of the way.” Yvo de Boer, Executive Secretary of the United Nations Framework Convenction on Climate Change, said of the concluding agreement “This is a real breakthrough, a real opportunity for the international community to successfully fight climate change.”

Those famously liberal editors at The Economist² didn't see it quite that way:

Sadly, the substance did not remotely match the storyline. The only real achievement at Bali was a decision to set up a pilot project to investigate how to stop tropical deforestation (see article). Aside from that, the conference, with 15,000 delegates, activists and journalists, cost a great deal in money, carbon and political energy and produced nothing but a vapid statement of good intentions, from which America ensured that all substance was removed.

Now I'm all for reducing tropical deforestation, but thanks to the United States' intransigence, there won't be real progress on reducing greenhouse gas emissions until there's a new administration in the White House. And as the Diffenbaugh paper shows, that's a really bad idea – even for those of us who live in the United States.

Summary of 21st century socioclimatic exposure (from Diffenbaugh et al.; view larger image in a popup window

Diffenbaugh and his colleagues construct a series of indices to reflect the susceptibility of different countries to climate change. These indices assess not only how much impact climate change will have onevery country³, but the number of people affected by these impacts and the distribution of wealth and poverty in relation to these impacts. They summarize their results in the single figure at the left as an index of socioclimatic exposure to impacts of climate change. A value of 1 corresponds to the maximum socioclimatic exposure.

It may not be too surprising to see Bangladesh colored dark red. It's a poor country with very little capacity to respond to major environmental disasters,⁴ but look closely at those two large splotches of dark red – China, part of India, and the eastern United States. “[A]ll three of the major unconstrained emitters of GHGs [greenhouse gases] – the United States, India, and China – face considerable vulnerabilities over the next 100 years, even on a per capita basis”

So what do we do until 2009? Here's what The Economist suggests:

As Bali showed, politics has a habit of undermining economics. A global carbon price remains a distant hope, and the planet is getting warmer. In its absence, targeting dirty industries is a stop-gap.

A global carbon tax is probably the best solution, but until we can get that let's raise fuel economy standards on cars and trucks, invest in alternative energy sources,⁵ and encouraging energy-efficient lighting, heating, and cooling. It's not all we need, but it's a step in the right direction, and one step forward now is better than standing still.

¹“Thunderous applause” is how The Economist described it.

²Just in case you don't recognize sarcasm when you see it. The Economist emphatically not a leftist, environmentalist rag. It endorsed George W. Bush for President in 2000 (though not in 2004) and was an ardent supporter of the invasion of Iraq. It's liberal only in the European sense of favoring free trade, the free market, and minimal restrictions on business activity.

³And parts of some countries.

⁴Like Tropical Cyclone Sidr.

⁵While being careful about biofuels, especially corn-based ethanol.