The Washington Post reports: It has been heralded as an unprecedented achievement. This year the vast majority of the world’s nations have issued pledges, or “intended nationally determined contributions” (INDCs), promising a range of emissions cuts as a foundation for an agreement at the Paris climate conference that opens Monday.

But there’s a problem. These commitments, on their own, only have the potential to forge a path that would limit warming to 2.7 degrees Celsius above pre-industrial levels at best, according to the U.N. And other assessments have been even more pessimistic than that, producing higher estimates like 3.5 degrees Celsius by 2100.

That’s well above the 2 degrees C that has been dubbed the final marker of a climatic “safe” zone. And now, a group of scientists who study the “cryosphere” — all the ice and snow in the Earth’s system, at the poles but also in frozen permafrost and mountain glaciers — have unleashed a stark assessment of just how inadequate these currently pledged emissions cuts are (barring a major enhancement of ambitions in Paris). Indeed, they say that if the INDCs are the end of the story, often irreversible changes will usher in that, unfolding over vast time periods, will dramatically raise seas and pour dangerous additional amounts of carbon into the atmosphere. [Continue reading…]