( CNN ) -- The world is facing an increasing risk of `` irreversible '' climate shifts because worst-case scenarios warned of two years ago are being realized , an international panel of scientists has warned . Drought , flooding , storms and mass extinction in the future will have a heavy social cost as well . Temperatures , sea levels , acid levels in oceans and ice sheets were already moving `` beyond the patterns of natural variability within which our society and economy have developed and thrived , '' scientists said in a report released Thursday . The findings came at the end of a three-day conference in Copenhagen , Denmark , where nearly 2,000 researchers gathered to discuss climate change . The group called on policy-makers to use all tools available to reduce dangerous emissions of greenhouse gases . The current climate situation on the planet may be as severe as the worst-case scenarios predicted by the Intergovernmental Panel on Climate Change ( IPCC ) , which issued warnings in 2007 of a future beset by flooding , drought , storms and mass extinction of species . In its report , the researchers also warned of potential social costs across the planet because of climate change . Temperature rises above 2 degrees Celsius would lead to climate disruption for the rest of the century and disproportionately affect poor nations , the researchers warned . `` Recent observations show that societies are highly vulnerable to even modest levels of climate change , with poor nations and communities particularly at risk , '' the report said . The conclusions of the conference will be presented to politicians when they meet in Copenhagen in December . It is then that leaders will discuss a new global agreement on greenhouse gas emission levels to replace the Kyoto Protocol , which expires in 2012 .
Worst-case scenarios warned of two years ago are being realized , says scientists . Findings came at the end of a three-day conference in Copenhagen . Poor nations will be disproportionately affected by climate change .