Elusive solutions

"There is a value in international negotiations: they can help shore up a sense of purpose; they can provide something by way of sticks and carrots. But an international agreement will not lead any government to follow climate policies that are clearly not supported at home for reasons of ideology, cost, or any other factor," Morton observes. Equally true is the fact that real breakthroughs in curbing emissions would involve real sacrifices.

As Oliver Geden wrote on this page recently ("Small step could lead to green progress," December 2), "The top-down approach that has guided the effort since 1992 is slowly being replaced by a bottom-up model."

In other words, rather than attempting to craft an accord based on legally binding restrictions on greenhouse-gas emissions, the new approach relies on voluntary commitments to emission reductions.

While small pragmatic steps from individual countries may be better than grand but unrealistic targets, Geden admits that such an approach does not encourage hope for reaching the goal of limiting the rise in global temperatures to less than two degrees Celsius, the target set by the United Nations in 2010.

Thus action on cutting down on fossil fuel consumption is hard technically, hard on big spenders, and hard on investors in fossil fuels, who would certainly lobby against any such action.

It is against this background that Morton comes up with his visionary proposal: Climate geoengineering.

This refers to the deliberate modification of the climate, and includes such technologies as stratospheric veils against the sun, the cultivation of photosynthetic plankton, fleets of unmanned ships seeding the clouds, or pulling carbon dioxide out of the air.

"When the change that humans bring to this new Anthropocene state of the earthsystem is deliberate, I see it as geoengineering; in this book, that term will cover any deliberate technological intervention in the earthsystem on a global scale," Morton explains.