Commentary: Time to combat climate change is now

Today 56 newspapers in 45 countries take the unprecedented step of speaking with one voice through a common editorial. We do so because humanity faces a profound emergency.

The dangers of climate change have been apparent for a generation. Now the facts have started to speak: 11 of the past 14 years have been the warmest on record, the Arctic ice cap is melting and last year's inflamed oil and food prices provide a foretaste of future havoc.

Climate change has been caused over centuries, has consequences that will endure for all time and our prospects of taming it will be determined in the next 14 days. We call on the representatives of the 192 countries gathered in Copenhagen not to blame each other but to seize opportunity from the greatest modern failure of politics. This should not be a fight between the rich world and the poor world. Climate change affects everyone.

The science is complex but the facts are clear. The world needs to take steps to limit temperature rises to two degrees Centigrade (3.6 degrees Farenheit), an aim that will require global emissions to begin falling within the next five-10 years. A bigger rise of three or four degrees C (5.4-7.2 F) -- the smallest increase we can expect to follow inaction -- would parch continents, turning farmland into desert. Half of all species could become extinct, millions of people would be displaced, whole nations drowned by the sea. The controversy over e-mails by British researchers that suggest they tried to suppress inconvenient data has muddied the waters but failed to dent the mass of evidence on which these predictions are based.

Few believe that Copenhagen can produce a treaty; real progress toward one could only begin with the arrival of President Obama in the White House and the reversal of years of U.S. obstructionism. But the politicians in Copenhagen can agree on the essential elements of a fair and effective deal and, crucially, a firm timetable for turning it into a treaty. Next June's U.N. meeting in Bonn should be their deadline.

To read the complete editorial, visit The Miami Herald.