As for whether an actual increase in emissions could happen globally over the next eight years — that’s also uncertain. In the past three years, global emissions have appeared to flatten but have not yet gone down. Less coal burning in China and the United States appears to be a key driver of this trend. Once again, it’s not clear that the United States’ intransigence alone could set off more emissions growth in a world in which clean energy growth is looking pretty dynamic.

Still, despite using a very different methodology, the new analysis fits with the previous one by Climate Interactive. A Trump administration hostile to international climate agreements cannot substantially change the planet’s temperature alone over eight years — but it can cause considerably more of an impact if it leads other nations to halt their own actions, or to step back from the clean energy revolution.

It is important to reiterate that keeping global warming below 2 degrees Celsius above preindustrial levels was already going to be extremely difficult no matter who the U.S. elected president — and that the climate impacts we have seen so far are already pretty grave.

So really, we are on a road to considerable damage no matter what, and likely some impacts that will be irreversible on any human time-scale. In this context, while we can’t know the future, we can definitely say that disengagement by the United States has the potential to make things worse — but that it will depend on how the entire world responds.

It is, after all, global warming.

December 27 at 12:53 PM