The agreement just announced from the Climate Conference in Paris isn’t by any means, a solution to the problem of avoiding climate change. But, along with other developments over the past year, it signals the fact that the world community has turned the corner on this issue. Barring a catastrophe[^1], the world is now on the path to near-complete decarbonization of the economy by the middle of this century, and to stabilization of the global climate with less than 2 degrees of warming.

The big developments of the past year include:

* An apparent (though small) decline in global CO2 emissions in 2015

* Peak Coal. Not only has global consumption of coal begun to fall, but the pressure to abandon coal, exerted at every stage from the initial financing of mines to the burning of coal in power stations has grown in intensity.

* Continued progress in renewables, notably including the appearance of commercially viable battery storage systems. It’s now obvious that, taking all the costs into account, renewable electricity is cheaper than the fossil fuel alternatives, and capable of completely replacing them.

* The political eclipse of leading denialists, most notably Abbott and Harper, and the disarray of US Republicans on the issue

* Looking at the agreement itself, it’s as ambitious as could reasonably have been hoped. Big points include
– The adoption of 1.5 degrees as a goal towards which efforts will be aimed
– The “ratchet” mechanism of 5 year reviews
– The acceptance that all countries need to act to reduce emissions over time.

Taken together, these developments put the world on a path to steadily more ambitious reductions in greenhouse gas emissions, consistent with stabilization of the global climate at 2 degrees of warming or less.

[^1]: The most obvious possible catastrophe would be a Republican victory in the 2016 US elections. But the momentum for change is such that even four years of unified Republican rule would probably not be enough to stop it.