The head of the UN climate panel painted a stark picture of the future unless nations agree tough emissions curbs to control global warming.
Following are some of the key points from Rajendra Pachauri's speech on Monday to delegates from nearly 200 countries gathered in Copenhagen for December 7-18 talks aimed at sealing the outlines of a climate pact.
Pachauri, drawing on the work of the panel's 2007 Fourth Assessment report, said climate change, without steps to curb the rapid growth of planet-warming carbon emissions and deforestation, would in all likelihood threaten the livelihoods of billions of people.
He told delegates the world faced:
— More heat waves and heavy rainfall events;
— Increase in tropical cyclone intensity;
— Possible disappearance of Arctic sea ice by the latter part of the 21st century;
— Decrease in water resources in semi-arid areas, such as the Mediterranean Basin, western United States, southern Africa and north-eastern Brazil;
— Possible elimination of the Greenland ice sheet and a resulting contribution to sea level rise of about 7m;
— Approximately 20 to 30% of species at increased risk of extinction if increases in global average warming exceed 1.5 to 2.5 degrees Celsius;
— Greater stress on water resources from population growth and economic and land use change, including urbanisation;
— Significant future increase in heavy rainfall in many regions as well as some in which the mean rainfall is likely to drop. Greater flood risk threatens infrastructure and water quality;
— Likelihood that 20% of the world population, or more than two billion people, will live in areas where river flood potential could increase by the 2080s;
— Increasing threat to low-lying island nations and coastal cities and deltas from rising seas. Seas are already rising because of melting glaciers and icesheets as well as expansion of the oceans as they warm;
— Even keeping global average temperatures to within 2 degrees C would likely lead to sea level rise of between 0.4 and 1.4m because of thermal expansion of the oceans;
— In Africa, by 2020, between 75 and 250 million people are projected to be exposed to water stress due to climate change and in some African countries, agricultural yields could be cut by half.
— To limit the average global rise in temperatures to between 2 and 2.4 deg C, the cost of curbing emissions by 2030 would not exceed 3% of global GDP, the climate panel says.
— Global emissions need to peak by 2015 to ensure that the temperature rise stays within 2 to 2.4 deg C.