The sun shines on a glacier. (BIGSTOCKPHOTO)

“Global warming” and “climate change” succinctly describe a complicated phenomenon, and in just a few decades they have become common descriptors. But while global warming would be bad for the Earth as a whole, the accumulation of greenhouse gases in the atmosphere would affect different areas in different ways, and local climate change is what matters to many people. So let’s look at the relative winners and losers.

Two factors will likely determine whether a particular region will prosper or suffer as climate change progresses: starting temperature and adaptability.

You don’t hear much talk about it, but countries that are cold right now could see very real benefits from a few extra degrees. Consider the Northern Sea shipping route, which runs through the Arctic waters north of Europe and Asia. It’s a faster and cheaper way to ship oil from Russia and Norway to markets around the world, but it’s currently too icy to navigate for much of the year. Climate change could open the route earlier and keep it clear later. It may also allow companies to extract new oil and mineral wealth from beneath the sea.

Immigration patterns may shift as different areas become more comfortable. In his book “The World in 2050,” UCLA professor Laurence C. Smith notes that cold-weather Canada has the look of a future superpower. Over the next four decades, the country’s population growth rate will be among the highest in the developed world.

There’s also a potential farming benefit. According to the International Panel on Climate Change, global warming could improve agricultural productivity in northern Europe.

The region might see as much as a 30 percent increase in wheat production, for example, by 2080. Some countries will become hospitable to foods they can’t grow in 2012. There may be a 50 percent increase in the areas of Sweden and Finland that are suitable for growing corn.

“There’s a perception that Norway will be a climate-change winner, and some have even talked about growing wine grapes,” says Karen O’Brien, a professor of sociology and human geography at the University of Oslo who has written about the winners and losers in the future world of climate change.

She cautions Norwegian policymakers against irrational climate-change exuberance, though. “Once you go above [an increase of] three or four degrees Celsius [about five to seven degrees Fahrenheit], it’s hard to imagine anyone benefitting. Changes in precipitation patterns and volume could undermine the temperature benefits, and the warmer winters could open the area to new pests and invasive species.”

When you talk to climate scientists about winners and losers, a few words come up over and over again: could, might, maybe. According to University of Arizona environmental economist Derek Lemoine, local climate-change patterns are difficult to predict because uncertainties in the global model “are compounded when considering smaller scales.”

For this reason, it’s very hard to pin down climate scientists on local effects. Klaus Keller, an associate professor of geosciences at the Pennsylvania State University, is working to develop strategies to manage the effects of climate change. I posed a simple question to him: If the leaders of Russia or Norway asked whether their countries would be better off in 50 years if the temperature increased by a few degrees, what would you say?

“We don’t know,” he replied.

Keller chafes at the notion of climate-change winners. “It’s one thing that, on average, the yield of a few cultivars can increase,” he says. “But heat waves increase mortality, increased drought makes life less enjoyable, and extreme weather events can be quite damaging.”

Keller argues that adaptability is the more important factor in determining how countries will fare. The most obvious and tragic cases of adaptability have to do with elevation. Mohamed Nasheed, president of the Maldives, has been among the most vocal proponents of climate-change mitigation, arguing that rising sea levels could leave his island nation underwater.

But in most cases, adaptability largely comes down to money.

India and the United States provide a stark example of this. Michael Greenstone, a professor of environmental economics at the Massachusetts Institute of Technology, and his colleagues have pored over death records for the past several decades in those countries to see how changes in temperature affect national death rates. He found that hotter days have only a modest effect on the U.S. mortality rate. In rural India, however, changing just a single day from a comfortable low 70s to a stifling low 90s increases the annual mortality rate by more than 1 percent. That’s from just one day of additional heat. The scary part of the research is that most climate models predict a far more dramatic change than that, with 30 or more additional days of extreme heat in India by the end of the century.

“When these results are combined with the predictions from one of the more popular climate-change models, they indicate a 50 percent increase in the annual mortality rate in India by 2100,” says Greenstone.

Why does the United States deal so much better with heat than India? We have plentiful access to heating and cooling technologies and the resources to smooth out our consumption patterns, according to Greenstone. If extreme heat — or extreme cold, for the matter — increases the cost of food, most Americans could take out loans to get themselves through the lean time. Indian farmers don’t have that option. Their resources are stretched as far as possible in good times, and they rely on the cash that comes with the harvest. If it falls short, many are pushed to death.