One climate change solution

A recent article in Science Magazine demonstrates how controlling methane and soot can have positive effects in a relatively short time on global warming, the Arctic, human health and agricultural productivity. It should be mandatory reading for all of the Republican presidential hopefuls and for President Barack Obama.

If the next president refocuses international climate negotiations on these eminently controllable greenhouse gas pollutants, a treaty could pay positive dividends within a decade or less. The methane and soot emissions can be controlled using current technology and the costs are moderate in comparison with the benefits.

From a political perspective, this is a win-win proposition. Its beauty is that it bypasses the contentious global and national debate over limiting carbon dioxide emissions while still addressing harmful human activity that not only adds to global warming but also shortens human lives. The health benefits would occur mainly in Asia, which contributes most to global soot production. Agriculture benefits would occur in most large nations, including the United States, China, India and Brazil.

The worldwide distribution of near-term positive gains should quickly persuade most nations to join in a coordinated effort to reduce methane and soot emissions.

The article's lead author, Drew Shindell, is a member in good standing with the climate change scientific community. He works for NASA's Goddard Institute for Space Studies, associated with Columbia University, and is a colleague of James Hansen, the scientist who inspired former Vice President Al Gore's Oscar-winning documentary on climate change.

The general model of climate change, which sees a large role for human activity in raising global temperatures, has come under close scrutiny in recent years because temperatures have stabilized over the past decade. But even die-hard climate change skeptics must acknowledge the photographic evidence from satellites showing how soot from auto exhausts, wood stoves and other sources has darkened Himalayan glaciers and the arctic ice sheet, accelerating melting.

Unlike carbon dioxide, which lingers in the atmosphere for decades, both soot and methane can be removed fairly quickly with positive effects. And methane is a more potent greenhouse gas than carbon dioxide. The Shindell study examines a number of different steps that can be taken to reduce methane and soot emissions. It is a good first step. But governments have to take the next steps.

Getting international agreement on a treaty setting limits on methane and soot emissions will require hard work on the details, hard bargaining and committed leadership.

The winner of this year's presidential race should welcome the challenge.