Slipping on climate crisis challenges
A new study suggests catastrophic warming is likely inevitable, as Earth is more sensitive to greenhouse gases than thought, challenging climate goals.
Is catastrophic warming of the planet now an inevitability? A new study in the journal Environment: Science and Policy for Sustainable Development suggests so. Former Nasa climate scientist and now Columbia University professor James Hansen, who is widely credited with pushing the term “global warming” from academic literature into the US and thereby global political lexicon, is among the authors. Hansen and his co-authors say that the Earth is more sensitive to warming from the emission of greenhouse gases (GHGs) than earlier believed and that the “2 degrees Celsius goal is dead”. This goal refers to scientific consensus on the threshold for warming above pre-industrial temperatures beyond which the worst of the climate crisis — such as the collapse of major ocean circulation systems and the abrupt melting of the northern permafrost — will occur. The Paris Agreement aims to limit warming well below this threshold, with an ambition of containing it within 1.5 degrees Celsius.

Some experts —Valerie Masson-Delmotte, a former top UN climate panel scientist among them — are sceptical about such a bleak assessment. But, for policy, the debate should only underscore how fast the world is slipping on climate action. Science and signs from nature, both point to the inadequacy of action so far: Last year was not only the hottest on record, but it also marked the breach of the 1.5 degrees Celsius warming cap. Contesting assessments of how much of a window we have must only encourage the global community to do much more than has been done and at a much faster rate. This needs to be kept in mind as climate talks yield little even as the Trump presidency in the US accelerates the collapse of the consensus on mitigation.