With a ton of land and plenty of weather variability, it will take much longer before a majority of the public feels the effects of extreme weather.

It's mighty big. (Photo: nicholas_t/Flickr)

There's a lot of land between shining sea and shining sea, and the weather patterns in most parts of this land are very different than the weather patterns in other parts of this land.

New research suggests this combination of America's vast land mass and climatic variability will continue to sabotage global efforts to slow down climate change. (That, and most of the country's residents are exposed to less severe climate hazards than those in smaller and less influential countries. Think Pacific island nations.)

Until collective concern about climate change among any nation's citizenry hits a tipping point, its leaders have little political incentive to take action. Meaningful global action is only likely to occur after a number of powerful countries have decided that such action is necessary. Not all countries are equal, and an effective international climate treaty would rely heavily on the support of two fossil fuel-burning heavyweights—the United States and China.

"On average, the model projects that the U.S. will have fewer and less extreme heat waves in highly-populated areas over the next several decades than other countries."

The research, published last month in Nature Climate Change, spells out how climate variability could be leading to delays within China and the U.S. when it comes to getting serious about bringing the burning of fossil fuels to an overdue end.

"This is the first attempt to bring together results from behavioral research on the psychology of climate change with research on the physical climate response to rising greenhouse gases," says Kate Ricke, a lecturer at Stanford University's Department of Environmental Earth System Science and one of two authors of the paper.

Study after study has revealed that people don't care so much about scientific warnings of global warming's looming consequences—they only really start to care after they've personally been affected. While the number of heat waves, droughts, storms, and floods linked to climate change continues to tick upward, these weather extremes still only affect a relatively small proportion of citizens of most countries in any given year.

Ricke and fellow Carnegie Institution for Science researcher Ken Caldeira analyzed a climate model ensemble with the assumption that a nation's tipping point for strong climate action would be reached after half of its residents suffered through particular types of extreme weather. They found that such tipping points take the longest to reach in large countries with variable weather patterns and relatively low climate dangers. "In contrast," they write in their paper, "for a small country one extreme event will often push the entire population past a tipping point."

Check out this chart from the paper:

(Chart: Nature Climate Change)

Here's a more global perspective:

(Map: Nature Climate Change)

"Time-to-action in the paper is driven by how often and how extreme heat waves are in highly populated areas," Ricke says, adding that a similar analysis of heavy downpours yielded similar results. "On average, the model projects that the U.S. will have fewer and less extreme heat waves in highly-populated areas over the next several decades than other countries."