Pollution From U.S., Europe, Others Speeding Arctic Warming, Study Says
for National Geographic News
|March 16, 2007|
Pollution from industrialized countries is heating the Arctic atmosphere faster than any region on Earth, a new study warns.
European researchers writing in today's issue of the journal Science report that temperature spikes in the Arctic are mainly caused by "human-induced emissions of long-lived greenhouse gases."
Ship emissions, smoke from summer forest fires, and air pollutants such as aerosols and ozone coming from the lower latitudes are contributing to "significant warming trends," the report authors say.
Surface air temperatures in the region have risen faster than the global average over the past few decades and "are predicted to warm by 5 degrees Celsius [9 degrees Fahrenheit] over a large part of the Arctic by the end of the 21st century," the authors note in their study.
Previous climate models have suggested that the Arctic's summer sea ice may completely disappear by 2040 if warming continues unabated.
"The Arctic is at risk because global warming is proceeding fastest there," said study co-author Andreas Stohl of the Norwegian Institute for Air Research.
"This is mainly a consequence of the increasing trends of long-lived greenhouse gases and feedbacks in the climate system, which are strongest in the Arctic."
Even though the Arctic receives a large amount of sunlight in the summer, the high reflectivity of its snow and ice surfaces usually keeps the ground from absorbing much of the heat.
But the Arctic atmosphere is dry and stable, which allows long-lasting aerosols and trace gases arriving on the wind to more easily build up and form what's known as the Arctic haze.
This haze of pollutants absorbs heat from sunlight and can speed up warming.
The light that passes through the haze and reaches the highly reflective snow and ice is bounced back through these gases, offering greater opportunity for them to capture the sun's heat.
Practically all pollution in the high Arctic arrives from more southerly latitudes, the authors said. But declining sea ice could lead to more local pollution sources.
"If large portions of sea ice disappear, more pollution and stronger climate effects are predicted because of the increase in shipping and Arctic oil drilling," the researchers say.
In addition, as northern high latitudes warm, boreal forest fires are increasing.
The phenomenon could lead to "a feedback cycle where forest-fire emissions lead to earlier melting of Arctic snow and ice, and thus further warming."
Inuits Feeling the Heat
The Northern Arctic's indigenous communities say they are already living with the consequences of diminished sea ice.
"Up here, climate change is very real," says Charlie Johnson, a 68-year-old Inuit man who serves as the executive director of the Alaska Nanuuq Commission, a group formed to protect the polar bear.
"As the sea ice goes out earlier and gets thinner, it affects our subsistence reliance on walrus and polar bears."
Johnson says polar bears and walruses travel across sea ice and use it as a staging ground for feeding. Now the animals are increasingly forced to stay on shore.
(Related news: "Polar Bears Suffering as Arctic Summers Come Earlier, Study Finds" [September 21, 2006].)
Johnson said an unusually large group of 50,000 walruses recently congregated near a Chukchi village on the north coast of the Chukotka peninsula.
"When they group together like that, their social structure breaks down and subjects them to stampedes and other stresses," he said.
"We found 198 walrus carcasses when they left. That causes polar bears to come and feed, and then you have more human-bear encounters."
Duane Smith, an Inuit who heads the advocacy group the Inuit Circumpolar Conference, said ice problems are impacting human mobility and hunting.
"With reduced and poor ice or no more ice in areas that we have adapted to for thousands of years, it is severely impacting our way of life and relationship with the environment around us," he said.
Inuit groups have tried to press industrialized nations to limit their emissions.
But Brian Smith, a spokesperson for the legal group Earth Justice, said "there is no legal action pending."
In 2005 Inuit groups did file a petition with the Inter American Commission on Human Rights, prompting the body to hold a hearing on March 1 regarding global warming and human rights.
Sheila Watt-Cloutier, an Inuit activist and a 2007 Nobel Peace Prize nominee, addressed the group, spelling out the cultural and environmental threats and pleading with industrialized countries to take action.
"These impacts are destroying our rights to life, health, property, and means of subsistence," Watt-Cloutier said. "States that do not recognize these impacts and take action violate our human rights."
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