“Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems,” the report declared.

In the starkest language it has ever used, the expert panel made clear how far society remains from having any serious policy to limit global warming.

Doing so would require finding a way to leave the vast majority of the world’s reserves of fossil fuels in the ground, or alternatively, developing methods to capture and bury the emissions resulting from their use, the group said.

If governments are to meet their own stated goal of limiting the warming of the planet to no more than 3.6 degrees Fahrenheit, or 2 degrees Celsius, above the preindustrial level, they must restrict emissions from additional fossil-fuel burning to about 1 trillion tons of carbon dioxide, the panel said.