Little attention has been given to reducing emissions of the light-absorbing particles known as "black carbon" or the gases that form ozone--even though doing so would be easier and cheaper and have a more immediate effect.

The free market has eliminated environmental hazards in the past, from leaded gas to acid rain, and it can solve the problem of climate change today.

As climate change accelerates, policymakers may have to consider "geoengineering" as an emergency strategy to cool the planet. Engineering the climate strikes most as a bad idea, but it is time to start taking it seriously.

The United States can curb its own emissions and encourage energy effeciency and the development of clean-energy technology worldwide by rethinking carbon regimes.

Oil stocks can help buffer economic shocks, but only if Washington radically reforms its handling of them.

The world has grown much more peaceful over the past 15 years -- except for oil-rich countries. Oil wealth often wreaks havoc on a country's economy and politics, helps fund insurgents, and aggravates ethnic grievances. And with oil ever more in demand, the problems it spawns are likely to spread further.

Wake up, Henry Hudson: Thanks to global warming, the Northwest Passage will soon be open for business.

China's environmental woes are mounting, and the country is fast becoming one of the leading polluters in the world. The situation continues to deteriorate because even when Beijing sets ambitious targets to protect the environment, local officials generally ignore them, preferring to concentrate on further advancing economic growth. Really improving the environment in China will require revolutionary bottom-up political and economic reforms.

Thanks to high oil prices and hefty subsidies, corn-based ethanol is now all the rage in the United States. But it takes so much supply to keep ethanol production going that the price of corn -- and those of other food staples -- is shooting up around the world. To stop this trend, and prevent even more people from going hungry, Washington must conserve more and diversify ethanol's production inputs.

Those who worry about the vulnerability of the world's oil shipping lanes should calm down. Oil tankers are more resilient than often presumed, and only the United States has the capability to seriously disrupt maritime traffic -- which it will not do.

The world needs more energy, and there is one clean, efficient, and safe way to get it: nuclear power. As the global appetite for electricity grows, atomic power -- which scarcely pollutes, generates relatively little solid waste, and is far more efficient than the alternatives -- should be embraced. A worldwide effort to develop and share nuclear technology is in all our interests.

Chinese foreign policy is now driven by China's unprecendented need for resources. In exchange for access to oil and other raw materials to fuel its booming economy, Beijing has boosted its bilateral relations with resource-rich states, sometimes striking deals with rogue governments or treading on U.S. turf. Beijing's hunger may worry some in Washington, but it also creates new grounds for cooperation.