As Californians sweat through another day of crazy heat, a new study finds that climate change is going to take a much greater toll on the economy than previously estimated.

A paper in the journal Nature finds that brutal heat waves, crop-killing droughts and rising seas will cost society more than three times what the U.S. government has forecast.

That’s what’s known as a wake-up call.

But, as with most prior climate-change predictions and warnings, it too will probably go unheeded until disaster is already knocking at our door.

The new study looks at what’s known as the “social cost of carbon.” It finds that each additional ton of carbon dioxide spewed into the atmosphere will cost society $185, or more than triple the current estimate.

“The bottom line is that our results show that when you fully update the social cost of carbon methodology to the state of the science, it suggests that the existing estimates that are in use by the federal government are vastly underestimating the harm,” the Washington Post quoted one of the report’s authors as saying.

This impacts all of us because, in the end, we’ll all pay for living in a world that wasn’t designed to be this hot.

And, as activists have been warning for years, the longer we wait to mitigate the problems, the more it will cost to address these issues (if we can).

This is tough stuff — particularly in light of resistance from some political quarters to do take any long-term steps that would impact the short-term prospects of businesses.

It’s easy to be cynical that this latest alarm from scientists will similarly be shrugged off. That would be a mistake.

We have only one planet. And we’re drastically changing its environmental conditions.

That this will have economic repercussions is obvious.

That it will cost far more than previously thought to fix makes the need for prompt action all the more urgent.

Or our children and grandchildren can pay exponentially higher costs down the road.