U.K.: Review of the year: Our Worst Fears are Exceeded by Reality

. By Steve Conner, The London Independent, December 29, 2006.

"It has been a hot year. The average temperature in Britain for 2006 was higher than at any time since records began in 1659... Little winter snow in the Alpine ski resorts, continuing droughts in Africa, mountain glaciers melting faster than at any time in the past 5,000 years, disappearing Arctic sea ice, Greenland's ice sheet sliding into the sea... You could be forgiven for thinking that you've heard it all before. You may think it's time to turn the page and read something else. But you'd be wrong. 2006 will be remembered by climatologists as the year in which the potential scale of global warming came into focus. And the problem can be summarised in one word: feedback... Everywhere scientists looked in 2006, they encountered [positive] feedbacks that will make things worse - a lot worse... Artic ice that reflected sunlight melts, exposing dark ocean that absorbs more sunlight and heats up, causing more ice to melt... Frozen peat bogs that turn into heat-absorbing lakes release methane, which means a stronger greenhouse effect and higher temperatures, leading to more permafrost melting... Another study in 2006 looked at perhaps the most important climate feedback there is. Yet it went unreported - so listen up. The Earth has been a very accommodating planet. During the past 200 years, it has absorbed more than half of all man-made emissions of carbon dioxide through natural carbon 'sinks', mostly in the ocean but also on land. The rest of the emissions have been left in the air to aggravate the Earth's natural greenhouse effect, so raising global average temperatures... [extensive computer modeling indicates] that as the world heats up, the ability of the land and the oceans to keep on absorbing carbon as efficiently as they have in the past 200 years gets appreciably worse... In other words, we cannot rely on planet Earth to be so accommodating in terms of mopping up half of our carbon pollution. But could something even worse happen? Could these carbon sinks turn into carbon sources? The answer is yes... It happened 55 million years ago when a trillion tons of methane were suddenly and mysteriously released from frozen stores on the seabed, causing global temperatures to soar 10C, and a mass extinction of species."