It’s hard to be optimistic about climate action, not in a week when federal scientists reported that “the Arctic shows no sign of returning” to the “reliably frozen region of recent past decades.” Not in a month when California’s wildfires show every sign of burning straight through Christmas. And not in a moment when the federal government keeps scrubbing basic climate information from its websites.

But something big is starting to shift. After years of effort from activists, there are signs that the world’s financial community is finally rousing itself in the fight against global warming. A foretaste came last month when Norway’s sovereign wealth fund — the world’s biggest — said that it is considering divestment from holdings in fossil fuel companies.

The Norwegians are far from the first to consider such a move (investors controlling more than $5 trillion in assets have committed to dropping all or some of their fossil fuels stocks) but they are the biggest. And since their fund had been built on the revenues from North Sea oil it was especially significant. It was as if they were preparing to cash in their chips from the hydrocarbon casino and heading out to look for a new game.

Then, in short order this week:

• The European insurance giant Axa announced it would divest itself of more than $825 million in investments in oil production and pipelines in the tar sands of Canada for both ethical and business reasons. The planet could see temperature increases as high as four degrees Celsius (7.2 degrees Fahrenheit), noted Thomas Buberl, the company’s chief executive, a development he called “not sustainable and therefore also not insurable.” He added, “As the father of two children, I really want to do the most I can with the company I am leading” to slow the rate of planetary destruction.