It has become common to focus on the fastest-warming places, regions where human-charged climate change is raising temperatures at an alarming speed. In the Arctic, where sea ice is rapidly disappearing, warming may be occurring more than four times faster than anywhere else on the planet. The World Meteorological Organization said recently that Europe, where extreme summer heat has killed thousands in recent years, is the fastest-warming continent.
On the flip side of the world’s global warming hot spots: parts of the planet that are warming more slowly than others, often much slower than the global average of about 1.1 degrees Celsius (2 degrees Fahrenheit) since the middle of the 20th century, according to a Washington Post analysis of data from the nonprofit organization Berkeley Earth.
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But rather than offer lessons for how to limit temperatures from rising, these relatively cool spots offer yet another example of how humanity has damaged the planet.
They are among the places where global warming’s influence is weakest, mainly because of man-made factors: air pollution, the ozone hole and melting ice.
Here are a few of them, and the influences behind them:
The scale for the thickness of the ozone layer ranges from 0 to 500 Dobson units. Scientists use the word “hole” to describe areas with ozone concentrations below 220 Dobson units. Source: NASA Earth Observations
While western Antarctica is one of the fastest-warming places on Earth, the eastern part of the planet’s coldest continent has warmed much more slowly.
One reason, scientists believe, is the ozone “hole,” a thinning in the atmospheric layer that acts as a shield for harmful ultraviolet sunlight. Though efforts to curtail use of ozone-depleting chemicals have helped to shrink the hole, it is expected to remain for decades to come.
The theory is that the ozone hole alters circulation of high-level, weather-steering winds in a way that makes it harder for cold polar air to escape, said Robert Rohde, lead scientist for Berkeley Earth.
Parts of East Antarctica have even cooled slightly relative to temperatures from 1951 to 1980.
Another factor that explains why Earth’s southern pole is warming so much more slowly than its northern one: Antarctica’s mountainous terrain, said Zeke Hausfather, climate research lead at financial company Stripe and a contributor to Berkeley Earth. The continent’s average elevation of more than 7,000 feet above sea level means more constant snow and ice cover, which means high albedo — an ability to reflect much of the sun’s rays and prevent the continent from absorbing as much solar radiation.
If Antarctica were as flat as the Arctic, one study found, it would warm much more quickly.
Change of ice thickness is only shown for Greenland, and is measured in meters of water equivalent. Source: NASA/JPL-Caltech
Some of the fastest warming on the planet is occurring in its iciest regions, including across the Arctic. But as a byproduct, melting ice means that some nearby waters are warming more slowly, if not cooling.
The effect is apparent in a small portion of the North Atlantic, just to the south of Greenland, where waters have cooled slightly and are also becoming so low in salinity that scientists fear an important ocean current is weakening. Ice losses in Greenland are so massive, they cannot be stopped, recent research found.
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An onslaught of cold water flowing from collapsing ice sheets has also been tied to cooling sections of the Southern Ocean around Antarctica. The relatively cool spot near Greenland is isolated; Antarctica and much of the global south are generally warming more slowly than areas in the north, said Gavin Schmidt, director of the NASA Goddard Institute for Space Studies.
“Oceans generally warm more slowly than the land, and the southern hemisphere has more ocean than the north,” Schmidt said in an email.
Among populous areas, India is one of the slowest-warming in part because of another byproduct of greenhouse gas emissions: air pollution.
Aerosols, or suspended fine particles in the air, generally have a cooling effect because they block and scatter sunlight and can stimulate cloud formation, Hausfather said.
And pollutants such as sulfur dioxide, released when sulfur-containing fuel such as coal, oil or diesel is burned, can be especially effective at cooling localized areas. Unlike, say, carbon dioxide, it does not spread far from where it is emitted, he said.
While European countries and the United States imposed regulations decades ago that have dramatically reduced air pollution, India continues to have some of the worst urban smog in the world, reaching “severe” levels last month.
That is not to say India can escape extreme heat, with its tropical humidity contributing to oppressive and dangerous conditions. But parts of the country have seen less than half a degree Celsius of temperature increase compared with its average temperatures from 1951-1980, less than half the global average.
On the flip side of the world’s global warming hot spots: parts of the planet that are warming more slowly than others, often much slower than the global average of about 1.1 degrees Celsius (2 degrees Fahrenheit) since the middle of the 20th century, according to a Washington Post analysis of data from the nonprofit organization Berkeley Earth.
Story continues below advertisement
But rather than offer lessons for how to limit temperatures from rising, these relatively cool spots offer yet another example of how humanity has damaged the planet.
They are among the places where global warming’s influence is weakest, mainly because of man-made factors: air pollution, the ozone hole and melting ice.
Here are a few of them, and the influences behind them:
A depleted ozone layer slows Antarctic warming
The scale for the thickness of the ozone layer ranges from 0 to 500 Dobson units. Scientists use the word “hole” to describe areas with ozone concentrations below 220 Dobson units. Source: NASA Earth Observations
While western Antarctica is one of the fastest-warming places on Earth, the eastern part of the planet’s coldest continent has warmed much more slowly.
One reason, scientists believe, is the ozone “hole,” a thinning in the atmospheric layer that acts as a shield for harmful ultraviolet sunlight. Though efforts to curtail use of ozone-depleting chemicals have helped to shrink the hole, it is expected to remain for decades to come.
The theory is that the ozone hole alters circulation of high-level, weather-steering winds in a way that makes it harder for cold polar air to escape, said Robert Rohde, lead scientist for Berkeley Earth.
Parts of East Antarctica have even cooled slightly relative to temperatures from 1951 to 1980.
Another factor that explains why Earth’s southern pole is warming so much more slowly than its northern one: Antarctica’s mountainous terrain, said Zeke Hausfather, climate research lead at financial company Stripe and a contributor to Berkeley Earth. The continent’s average elevation of more than 7,000 feet above sea level means more constant snow and ice cover, which means high albedo — an ability to reflect much of the sun’s rays and prevent the continent from absorbing as much solar radiation.
If Antarctica were as flat as the Arctic, one study found, it would warm much more quickly.
A flow of ice melt influences waters near Greenland
Change of ice thickness is only shown for Greenland, and is measured in meters of water equivalent. Source: NASA/JPL-Caltech
Some of the fastest warming on the planet is occurring in its iciest regions, including across the Arctic. But as a byproduct, melting ice means that some nearby waters are warming more slowly, if not cooling.
The effect is apparent in a small portion of the North Atlantic, just to the south of Greenland, where waters have cooled slightly and are also becoming so low in salinity that scientists fear an important ocean current is weakening. Ice losses in Greenland are so massive, they cannot be stopped, recent research found.
Story continues below advertisement
An onslaught of cold water flowing from collapsing ice sheets has also been tied to cooling sections of the Southern Ocean around Antarctica. The relatively cool spot near Greenland is isolated; Antarctica and much of the global south are generally warming more slowly than areas in the north, said Gavin Schmidt, director of the NASA Goddard Institute for Space Studies.
“Oceans generally warm more slowly than the land, and the southern hemisphere has more ocean than the north,” Schmidt said in an email.
Among populous areas, India is one of the slowest-warming in part because of another byproduct of greenhouse gas emissions: air pollution.
Aerosols, or suspended fine particles in the air, generally have a cooling effect because they block and scatter sunlight and can stimulate cloud formation, Hausfather said.
And pollutants such as sulfur dioxide, released when sulfur-containing fuel such as coal, oil or diesel is burned, can be especially effective at cooling localized areas. Unlike, say, carbon dioxide, it does not spread far from where it is emitted, he said.
While European countries and the United States imposed regulations decades ago that have dramatically reduced air pollution, India continues to have some of the worst urban smog in the world, reaching “severe” levels last month.
That is not to say India can escape extreme heat, with its tropical humidity contributing to oppressive and dangerous conditions. But parts of the country have seen less than half a degree Celsius of temperature increase compared with its average temperatures from 1951-1980, less than half the global average.
