USA Today
Scientists were sure climate change was bad for polar bears. Now they know how bad.
Doyle Rice, USA Today – September 1, 2023
There is a link between global warming and polar bears after all. And it’s not a good one.
According to a new study released Thursday, for the first time, scientists can measure the impact that greenhouse gas emissions have on polar bear cub survival. This is key because although scientists have known for years that a lack of sea ice could be devastating for polar bears, there was no methodology in place to quantify the specific effect that human-caused climate change had on the iconic species.
“Until now, scientists hadn’t offered the quantitative evidence to relate greenhouse gas emissions to population decline,” said study co-author Cecilia Bitz, a professor of atmospheric sciences at the University of Washington, in a statement.
Sea ice decline could eventually lead to extinction
Greenhouse gases such as carbon dioxide and methane are produced from the burning of fossil fuels such as oil, gas and coal. Those gases have warmed the world’s atmosphere and oceans and are leading to reduced amounts of sea ice in the Arctic.
Polar bears rely on that sea ice to hunt, and when the ice is absent, they are forced onto land where they cannot find food. As Arctic sea ice declines in response to warming temperatures, polar bears must fast for longer periods.
Researchers estimated the relationship between how long bears fasted and each gigaton of cumulative emissions.
Scientists have said most polar bears could become extinct by the end of the century unless warming is curbed.
More: Climate change may push polar bears to the brink of extinction within 100 years, study says
How does the study relate to the Endangered Species Act?
The study also has policy implications because it allows a formal assessment of how future proposed actions would impact polar bears.
Researchers believe it overcomes a legal roadblock in the Endangered Species Act that prevented the federal government from considering climate change when evaluating projects like oil and gas drilling.
The Department of Interior has said greenhouse gas emissions can’t be considered when evaluating a project’s effects on endangered species unless its emissions impact could be distinguished from historic global emissions.
“What’s really relevant for policy is emissions,” rather than atmospheric concentrations, said Bitz.
Study lead author Steven Amstrup of Polar Bear International said, “I consider this the most important paper of my career. It helps explain recently observed population trends, overcomes a stumbling block in U.S. policy, and can inform other countries considering development projects – finally giving polar bears the protection they need.”
Amstrup also believes the methodology used in the new study can be applied to many other species, such as sea turtles or coral reefs.
Bitz said that “I hope the U.S. government fulfills its legal obligation to protect polar bears by limiting greenhouse gas emissions from human activity. I hope investments are made into fossil fuel alternatives that exist today, and to discover new technologies that avoid greenhouse gas emissions.”
The study was published in the journal Science.
Contributing: The Associated Press
Scientists were sure climate change was bad for polar bears. Now they know how bad.
Doyle Rice, USA TODAYFri, September 1, 2023 at 3:14 PM CDT·3 min read95
There is a link between global warming and polar bears after all. And it’s not a good one.
According to a new study released Thursday, for the first time, scientists can measure the impact that greenhouse gas emissions have on polar bear cub survival. This is key because although scientists have known for years that a lack of sea ice could be devastating for polar bears, there was no methodology in place to quantify the specific effect that human-caused climate change had on the iconic species.
“Until now, scientists hadn’t offered the quantitative evidence to relate greenhouse gas emissions to population decline,” said study co-author Cecilia Bitz, a professor of atmospheric sciences at the University of Washington, in a statement.
Sea ice decline could eventually lead to extinction
Greenhouse gases such as carbon dioxide and methane are produced from the burning of fossil fuels such as oil, gas and coal. Those gases have warmed the world’s atmosphere and oceans and are leading to reduced amounts of sea ice in the Arctic.
Polar bears rely on that sea ice to hunt, and when the ice is absent, they are forced onto land where they cannot find food. As Arctic sea ice declines in response to warming temperatures, polar bears must fast for longer periods.
Researchers estimated the relationship between how long bears fasted and each gigaton of cumulative emissions.
Scientists have said most polar bears could become extinct by the end of the century unless warming is curbed.
More: Climate change may push polar bears to the brink of extinction within 100 years, study says
How does the study relate to the Endangered Species Act?
The study also has policy implications because it allows a formal assessment of how future proposed actions would impact polar bears.
Researchers believe it overcomes a legal roadblock in the Endangered Species Act that prevented the federal government from considering climate change when evaluating projects like oil and gas drilling.
The Department of Interior has said greenhouse gas emissions can’t be considered when evaluating a project’s effects on endangered species unless its emissions impact could be distinguished from historic global emissions.
“What’s really relevant for policy is emissions,” rather than atmospheric concentrations, said Bitz.
Study lead author Steven Amstrup of Polar Bear International said, “I consider this the most important paper of my career. It helps explain recently observed population trends, overcomes a stumbling block in U.S. policy, and can inform other countries considering development projects – finally giving polar bears the protection they need.”
Amstrup also believes the methodology used in the new study can be applied to many other species, such as sea turtles or coral reefs.
Bitz said that “I hope the U.S. government fulfills its legal obligation to protect polar bears by limiting greenhouse gas emissions from human activity. I hope investments are made into fossil fuel alternatives that exist today, and to discover new technologies that avoid greenhouse gas emissions.”
The study was published in the journal Science.
Contributing: The Associated Press
Scientists were sure climate change was bad for polar bears. Now they know how bad.
Doyle Rice, USA TODAY – September 1, 2023
There is a link between global warming and polar bears after all. And it’s not a good one.
According to a new study released Thursday, for the first time, scientists can measure the impact that greenhouse gas emissions have on polar bear cub survival. This is key because although scientists have known for years that a lack of sea ice could be devastating for polar bears, there was no methodology in place to quantify the specific effect that human-caused climate change had on the iconic species.
“Until now, scientists hadn’t offered the quantitative evidence to relate greenhouse gas emissions to population decline,” said study co-author Cecilia Bitz, a professor of atmospheric sciences at the University of Washington, in a statement.
Sea ice decline could eventually lead to extinction
Greenhouse gases such as carbon dioxide and methane are produced from the burning of fossil fuels such as oil, gas and coal. Those gases have warmed the world’s atmosphere and oceans and are leading to reduced amounts of sea ice in the Arctic.
Polar bears rely on that sea ice to hunt, and when the ice is absent, they are forced onto land where they cannot find food. As Arctic sea ice declines in response to warming temperatures, polar bears must fast for longer periods.
Researchers estimated the relationship between how long bears fasted and each gigaton of cumulative emissions.
Scientists have said most polar bears could become extinct by the end of the century unless warming is curbed.
More: Climate change may push polar bears to the brink of extinction within 100 years, study says
How does the study relate to the Endangered Species Act?
The study also has policy implications because it allows a formal assessment of how future proposed actions would impact polar bears.
Researchers believe it overcomes a legal roadblock in the Endangered Species Act that prevented the federal government from considering climate change when evaluating projects like oil and gas drilling.
The Department of Interior has said greenhouse gas emissions can’t be considered when evaluating a project’s effects on endangered species unless its emissions impact could be distinguished from historic global emissions.
“What’s really relevant for policy is emissions,” rather than atmospheric concentrations, said Bitz.
Study lead author Steven Amstrup of Polar Bear International said, “I consider this the most important paper of my career. It helps explain recently observed population trends, overcomes a stumbling block in U.S. policy, and can inform other countries considering development projects – finally giving polar bears the protection they need.”
Amstrup also believes the methodology used in the new study can be applied to many other species, such as sea turtles or coral reefs.
Bitz said that “I hope the U.S. government fulfills its legal obligation to protect polar bears by limiting greenhouse gas emissions from human activity. I hope investments are made into fossil fuel alternatives that exist today, and to discover new technologies that avoid greenhouse gas emissions.”
The study was published in the journal Science.
Contributing: The Associated Press