"Long before it's in the papers"
January 27, 2015


Climate engineering can’t stop global warming, scientists warn

June 4, 2014
Courtesy of 
and World Science staff

Tin­ker­ing with cli­mate change through cli­mate “engi­neer­ing” won’t help us avoid what we have to do to stop glob­al warm­ing, says a new re­port by re­search­ers at six uni­vers­i­ties.

Af­ter assessing a range of pos­si­ble cli­mate-altering ap­proaches to re­duc­ing warm­ing, the team con­clud­ed there’s no way around it: those ap­proaches may en­hance our oth­er ef­forts, but we have to re­duce the types of emis­sions re­spon­si­ble the warm­ing. Emis­sions of car­bon di­ox­ide and oth­er so-called green­house gas­es through hu­man ac­ti­vi­ties are con­sid­ered the cul­prits be­hind the warm­ing.

“Some cli­mate en­gi­neer­ing strate­gies look very cheap on pa­per. But when you con­sid­er oth­er cri­te­ria, like ec­o­log­i­cal risk, pub­lic per­cep­tions and the abil­i­ties of gov­ern­ments to con­trol the tech­nol­o­gy, some op­tions look very bad,” said re­search­er Jonn Axsen of Si­mon Fra­ser Uni­vers­ity in Brit­ish Co­lum­bia.

The as­sis­tant pro­fes­sor in the uni­vers­ity’s School of Re­source and En­vi­ron­men­tal Man­age­ment is a co-author of this stu­dy, which ap­pears in the lat­est is­sue of the jour­nal Fron­tiers in Ecol­o­gy and the En­vi­ronment. It de­scribes it­self as the first schol­arly at­tempt to rank a wide range of ap­proaches to min­i­miz­ing cli­mate change in terms of their fea­si­bil­ity, cost-ef­fec­tiveness, risk, pub­lic ac­cept­ance, gov­ern­abil­ity and eth­ics.

It states that the most ef­fec­tive way of con­fronting cli­mate change is re­duc­ing emis­sions through some com­bina­t­ion of switch­ing away from fos­sil fu­els to low-car­bon en­er­gy sources, im­prov­ing en­er­gy ef­fi­cien­cy, and chang­ing hu­man be­hav­ior. The au­thors added that strate­gies such as for­est man­age­ment and ge­o­log­i­cal stor­age of car­bon di­ox­ide may be use­ful com­ple­ments to emis­sion re­duc­tions.

Oth­er cli­mate en­gi­neer­ing strate­gies are less ap­peal­ing, the au­thors said, such as fer­ti­liz­ing the ocean with iron to ab­sorb car­bon di­ox­ide or re­duc­ing glob­al warm­ing by in­ject­ing par­t­i­cles in­to the at­mos­phere to block sun­light. “Take the ex­am­ple of so­lar radia­t­ion man­age­ment, which is the idea of put­ting aerosols in­to the strat­o­sphere, kind of like what hap­pens when a large vol­ca­no erupts,” Axsen ex­plained. “This is a sur­pris­ingly cheap way to re­duce glob­al tem­per­a­tures, and we have the tech­nol­o­gy to do it. But our study asked oth­er im­por­tant ques­tions. What are the envi­ron­men­tal risks? Will glob­al cit­i­zens ac­cept this? What coun­try would man­age this? Is that fair? Sud­den­ly, this strat­e­gy does not look so attrac­tive.” 

Work­ing un­der the aus­pic­es of the Na­t­ional Sci­ence Founda­t­ion, the au­thors spent two years eval­u­at­ing more than 100 stud­ies that ad­dressed the var­i­ous im­plica­t­ions of cli­mate en­gi­neer­ing and their an­ti­cipated ef­fects on green­house gas­es.

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Tinkering with climate change through climate “engineering” won’t help us avoid what we have to do to stop global warming, said a new report by researchers at six universities. After evaluating a range of possible climate-altering approaches to reducing warming, the interdisciplinary team concluded there’s no way around it: those approaches may enhance our other efforts, but we have to reduce the types of emissions responsible the warming. Emissions of carbon dioxide and other so-called greenhouse gases through human activities are considered the culprits behind the warming. “Some climate engineering strategies look very cheap on paper. But when you consider other criteria, like ecological risk, public perceptions and the abilities of governments to control the technology, some options look very bad,” said researcher Jonn Axsen of Simon Fraser University in British Columbia. The assistant professor in the university’s School of Resource and Environmental Management is a co-author of this study, which appears in the latest issue of the journal Frontiers in Ecology and the Environment. It describes itself as the first scholarly attempt to rank a wide range of approaches to minimizing climate change in terms of their feasibility, cost-effectiveness, risk, public acceptance, governability and ethics. It states that the most effective way of confronting climate change is reducing emissions through some combination of switching away from fossil fuels to low-carbon energy sources, improving energy efficiency, and changing human behavior. The authors added that strategies such as forest management and geological storage of carbon dioxide may be useful complements to emission reductions. Other climate engineering strategies are less appealing, the authors said, such as fertilizing the ocean with iron to absorb carbon dioxide or reducing global warming by injecting particles into the atmosphere to block sunlight. “Take the example of solar radiation management, which is the idea of putting aerosols into the stratosphere, kind of like what happens when a large volcano erupts,” Axsen explains. “This is a surprisingly cheap way to reduce global temperatures, and we have the technology to do it. But our study asked other important questions. What are the environmental risks? Will global citizens accept this? What country would manage this? Is that fair? Suddenly, this strategy does not look so attractive.” Working under the auspices of the National Science Foundation, the authors spent two years evaluating more than 100 studies that addressed the various implications of climate engineering and their anticipated effects on greenhouse gases.