O M I D
02-11-2015, 09:43 PM
A federal panel recommended studying
‘ Geoengineering ’ would be a risky last resort, scientists say
a kind of climate modification that would have far-reaching consequences. A federal panel of scientists has recommended studying ways that humans can alter the Earth to counter the effects of climate change — a strategy called “geoengineering” that experts say would be a reckless last resort
.
Reducing emissions of carbon dioxide is the best way to prevent the risk of dangerous climate change, said a panel assembled by the National Research Council of the U.S. National Academy of Sciences. But in case that effort fails, the panel urged the government to study ways to modify the atmosphere to reflect more of the sun’s light back into space, a technique called “albedo modification
.”
One way of doing that is by injecting large volumes of sulfate particles into the middle atmosphere to deflect sunlight before it reaches the Earth’s surface. That would be like installing an artificial thermostat to turn down the Earth’s dangerously rising temperature — last year was the hottest on record — by banishing some of the energy streaming to the Earth from the sun.
Scientists know that method would work because it’s what happens when large volcanic eruptions send plumes of ash into the air.
Tens of millions of tons of sulfate aerosol, for instance, could offset a doubling of carbon dioxide in the atmosphere.
But there would be side effects — the particles could alter where rain falls across the globe or further deplete ozone in the atmosphere. The consequences would be felt differently in various places
.
That scientists would advocate studying such a drastic step “should be a wake-up call that we need to do more now to reduce emissions, which is the most effective, least risky way to combat climate change,” committee chairwoman Marcia McNutt, editor in chief of the journal Science and former director of the U.S. Geological Survey, said in a statement
.
Indeed, the scientists wrote that artificially changing the Earth’s reflectivity, or albedo, would be “irrational” without also trying to reduce carbon dioxide. Such geoengineering would not solve the underlying problem of too much carbon dioxide.
Still, the committee recommended federally sponsored research on the matter to learn more about its risks and benefits, despite fears about the “moral hazard” of considering an action that could undermine the more fundamental work of reducing emissions
.
“The Committee argues that, as a society, we have reached a point where the severity of the potential risks from climate change appears to outweigh the potential risks from the moral hazard associated with a suitably designed and governed research program,” the panel wrote
.
Overall, the report represents a “big tent” approach, said Raymond Pierrehumbert, a geophysicist at the University of Chicago who served on the committee, suggesting a range of views among the participating scientists. (There were 16 committee members
.)
“One of the best things that could come out of the NRC report is to just alert people to the fact that unrestrained emissions could make the world so bad that we might do something like albedo modification just out of desperation,” Pierrehumbert said.
Reasoning that there are many scenarios in which we would need to know more about artificially changing the Earth’s reflectivity — such as if a rogue state decides to try it — the committee recommended that the U.S. Global Change Research Program coordinate studies on the matter and that the research be performed in such a way as to simultaneously increase basic knowledge of the climate system
.
The recommendation includes conducting “small-scale field experiments” with “controlled emissions” — provided that the experiments are too localized and minuscule in scale to have any significant climatic effect. All of this would need to take place, notes the committee, under the aegis of a deliberative process about how to govern geoengineering research, to ensure ethical considerations are weighed, and to balance risks and benefits
.
The National Research Council report was sponsored by a number of U.S. science agencies and the U.S. intelligence community. In a separate report, the council explored the subject of carbon-dioxide removal, which is considerably less controversial, and is mainly held back at the moment by technological and cost considerations
.
The idea is to use technology to remove the carbon dioxide that is in the atmosphere, because of human emissions. Its removal would also induce a cooling effect if deployed on a large enough scale
.
Fanned by climate concerns, the two reports arrive following a dramatic growth in scientific publications and discussions about geoengineering over the past decade. The British Royal Society, the world’s oldest scientific academy, also recommended government-sanctioned and organized research into geoengineering in a 2009 report
.
Until now, the research studies on geoengineering published in scientific journals generally have relied on computer simulations to study the hypothetical effects of various interventions. True outdoor experiments that change the world are another matter — but if the framework outlined by the National Research Council were to be adopted, they could go forward carefully.
‘ Geoengineering ’ would be a risky last resort, scientists say
a kind of climate modification that would have far-reaching consequences. A federal panel of scientists has recommended studying ways that humans can alter the Earth to counter the effects of climate change — a strategy called “geoengineering” that experts say would be a reckless last resort
.
Reducing emissions of carbon dioxide is the best way to prevent the risk of dangerous climate change, said a panel assembled by the National Research Council of the U.S. National Academy of Sciences. But in case that effort fails, the panel urged the government to study ways to modify the atmosphere to reflect more of the sun’s light back into space, a technique called “albedo modification
.”
One way of doing that is by injecting large volumes of sulfate particles into the middle atmosphere to deflect sunlight before it reaches the Earth’s surface. That would be like installing an artificial thermostat to turn down the Earth’s dangerously rising temperature — last year was the hottest on record — by banishing some of the energy streaming to the Earth from the sun.
Scientists know that method would work because it’s what happens when large volcanic eruptions send plumes of ash into the air.
Tens of millions of tons of sulfate aerosol, for instance, could offset a doubling of carbon dioxide in the atmosphere.
But there would be side effects — the particles could alter where rain falls across the globe or further deplete ozone in the atmosphere. The consequences would be felt differently in various places
.
That scientists would advocate studying such a drastic step “should be a wake-up call that we need to do more now to reduce emissions, which is the most effective, least risky way to combat climate change,” committee chairwoman Marcia McNutt, editor in chief of the journal Science and former director of the U.S. Geological Survey, said in a statement
.
Indeed, the scientists wrote that artificially changing the Earth’s reflectivity, or albedo, would be “irrational” without also trying to reduce carbon dioxide. Such geoengineering would not solve the underlying problem of too much carbon dioxide.
Still, the committee recommended federally sponsored research on the matter to learn more about its risks and benefits, despite fears about the “moral hazard” of considering an action that could undermine the more fundamental work of reducing emissions
.
“The Committee argues that, as a society, we have reached a point where the severity of the potential risks from climate change appears to outweigh the potential risks from the moral hazard associated with a suitably designed and governed research program,” the panel wrote
.
Overall, the report represents a “big tent” approach, said Raymond Pierrehumbert, a geophysicist at the University of Chicago who served on the committee, suggesting a range of views among the participating scientists. (There were 16 committee members
.)
“One of the best things that could come out of the NRC report is to just alert people to the fact that unrestrained emissions could make the world so bad that we might do something like albedo modification just out of desperation,” Pierrehumbert said.
Reasoning that there are many scenarios in which we would need to know more about artificially changing the Earth’s reflectivity — such as if a rogue state decides to try it — the committee recommended that the U.S. Global Change Research Program coordinate studies on the matter and that the research be performed in such a way as to simultaneously increase basic knowledge of the climate system
.
The recommendation includes conducting “small-scale field experiments” with “controlled emissions” — provided that the experiments are too localized and minuscule in scale to have any significant climatic effect. All of this would need to take place, notes the committee, under the aegis of a deliberative process about how to govern geoengineering research, to ensure ethical considerations are weighed, and to balance risks and benefits
.
The National Research Council report was sponsored by a number of U.S. science agencies and the U.S. intelligence community. In a separate report, the council explored the subject of carbon-dioxide removal, which is considerably less controversial, and is mainly held back at the moment by technological and cost considerations
.
The idea is to use technology to remove the carbon dioxide that is in the atmosphere, because of human emissions. Its removal would also induce a cooling effect if deployed on a large enough scale
.
Fanned by climate concerns, the two reports arrive following a dramatic growth in scientific publications and discussions about geoengineering over the past decade. The British Royal Society, the world’s oldest scientific academy, also recommended government-sanctioned and organized research into geoengineering in a 2009 report
.
Until now, the research studies on geoengineering published in scientific journals generally have relied on computer simulations to study the hypothetical effects of various interventions. True outdoor experiments that change the world are another matter — but if the framework outlined by the National Research Council were to be adopted, they could go forward carefully.