There is an overlooked benefit to greatly lowering carbon emissions, a study says. In addition to preserving Arctic sea ice, reducing sea-level rise and alleviating other effects of global warming, it could save more than 150 million human lives.

According to the study, premature deaths would fall on nearly every continent if the world's governments agree to cut emissions enough to limit global temperature rise to less than 3 degrees by the end of the century. That is about a degree lower than the target set by the Paris climate agreement.

The benefit would be felt mostly in Asian countries with dirty air — 13 million lives would be saved in large cities in India alone. The African cities of Lagos and Cairo combined would register more than 2 million fewer deaths. In the United States, the Clean Air Act has improved air quality. Still, more than 330,000 lives in Los Angeles, New York, San Francisco, Pittsburgh, Philadelphia, Detroit, Atlanta and Washington would be spared, said the study, published in the journal Nature Climate Change.

"Americans don't really grasp how pollution impacts their lives," said Drew Shindell, a professor of Earth science at Duke University and the lead author. "It's still a big killer here. It's much bigger than from people who die from plane crashes or war or terrorism, but we don't see the link so clearly."

Protected bears care longer for their cubs

Twenty-five years ago, brown bear mothers in Sweden rarely spent more than 18 months raising their cubs. Today, it's not unusual for moms to devote 2½ years to their cubs.

What's behind this new passion for parenting? Researchers attribute it to a hunting regulation that protects mother bears and their cubs. Data show that when moms feel under the gun, their best survival strategy is to have as many cubs as possible — which means weaning their young quickly.

However, when they don't feel pressured by hunters, they respond by investing more time and resources in their offspring. That gives the cubs a better chance of survival.

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