The world’s leading body of climate scientists has concluded global warming is “very likely” caused by human activity and may be impossible to stop. In its strongest language to date, the U.N.’s Intergovernmental Panel on Climate Change is predicting melting glaciers, rising temperatures and higher sea levels.

IPCC Chair Rajendra Pachauri: “I only want to draw your attention to the fact that we are, and if you look at the language of the summary for policymakers you’ll be able to read this, we are in a sense doing things that perhaps have not happened in 650,000 years.”

For the first time, the panel also said global warming has been the likely cause of increased hurricane and cyclone activity over the last 30 years. IPCC working group co-chair Susan Solomon warned of more unexpected changes if current trends continue.

Susan Solomon: “If we were to keep emitting greenhouse gases at or above the current rate, that would cause further warming and induce many changes in the global system, the global climate system, that would very likely be larger in the 21st century than they were in the 20th century.”