Can Geoengineering Technology Somehow Stave Off This Climate Mess?

July 15, 2010

Science Survey


Say "geoengineering" to most people, and few will know what you're talking about. Some wrongly associate the term with geothermal energy or green engineering, according to recent survey results from the Yale Project on Climate Change. That means we environmental journalists need to explain this subject carefully to our audiences.

So what is geoengineering? Some call it a Plan B to curb climate change if societies can't stop the buildup of greenhouse gases in the atmosphere fast enough. Or to Hack the Planet, as SEJ member Eli Kintisch titled his recent book on geoengineering. Some have likened it to installing a giant thermostat for Earth — and we humans would control it.

Geoengineering involves intentional human manipulation of the planet's climate. While batted about in scientific circles for years, this idea has remained relatively quiet. Many researchers dismissed the idea, revolted by the thought of such blatant intervention in Earth's natural systems.

Times have changed. Global greenhouse gas emissions continue to rise and governments aren't finding ways to curb them — witness the failure of last December's Copenhagen conference to produce a new climate change treaty.

At this point, relying on solely emission reductions may not stave off serious climate change fast enough to prevent irreversible or catastrophic environmental alterations. Scientists have their own jargon for saying this: they refer to the inertia in the Earth's climate system due to all the greenhouse gases we've pumped into the atmosphere.

Scientists point out that humans are already geoengineering the planet, albeit unintentionally, through our fossil fuel use and deforestation. Thus, some researchers have reluctantly embraced geoengineering as a rational preparation in the event of major changes such as release of methane from Arctic seas or land due to warming. Others are more gung-ho, seeing these technologies as an economically rational way to continue using fossil fuels — and avoiding serious emission cuts — until new energy sources are commercialized.

The research is moving forward, though still very few scientists are thinking about it. One key funder of this work is Microsoft magnate Bill Gates.

Geoengineering techniques — also known as climate intervention technologies — fall into two broad categories.

One involves deflecting incoming sunlight into space, curbing the amount of radiation that reaches the plant's surface and provides the heat that greenhouse gases trap in the atmosphere. A fairly inexpensive technology would be to spray sulfur dioxide gas into the stratosphere, where it would form droplets of sulfuric acid, which is highly reflective. Another would be to deploy specially equipped ships to gin up thicker, more reflective clouds over oceans. Other ideas bandied about are to launch mirrors into orbit around earth and painting roofs white, though recent reviews have panned these as either too expensive, not practical, or not very effective. Together, these sun-reflecting technologies go by the moniker "solar radiation management."

The second category encompasses efforts to strip carbon dioxide out of the atmosphere and lock it away for centuries. Some involve artificial trees that, through chemical reactions, would pull out CO2 for storage underground or in the bottom of the oceans. Another idea is for growing crops of real trees, which convert CO2 into biomass, then converting their wood into a material, called biochar, that doesn't decompose easily. Yet another proposal is to mine a mineral called serpentine, which reacts with atmospheric CO2 to form another mineral, carbonate.

Solar radiation management techniques, especially stratospheric aerosols, are expected to be fast and cheap to implement. They would require repeated application since their effects would only last for a few years and because stopping them suddenly could cause catastrophic warming. These reflective methods would do nothing about one very serious side effect of CO2 emissions — ocean acidification. And they carry serious global environmental justice implications if these technologies, as some computer models suggest, dry out sub-Saharan Africa or weaken the monsoon weather pattern that agriculture in southeastern Asia depends upon.

Carbon dioxide removal and storage would be more expensive and would take decades to make a dent in projected climate change. But these efforts are seen as having fewer potential side effects and would address ocean acidification.

Researchers are now talking about geoengineering field tests. They are crafting rules to guide their research. At the Asilomar International Conference on Climate Intervention Technologies, held in March in Pacific Grove, Calif., researchers collectively went public on geoengineering. They called for discussions among scientists, governments, and the public to ensure that research in this field is done responsibly and in a transparent fashion.

Concern about geoengineering research is emerging on the policy scene. The U.S. House of Representatives and the U.K. House of Commons are studying potential ways of governing geoengineering experiments. Environmental organizations are getting involved too. A newly formed green group, Hands Off Mother Earth, opposes geoengineering. Some more established environmental organizations haven't ruled out support for studying climate intervention techniques if they will help protect species and ecosystems from devastation due to global warming.

SEJ has long called climate change the story of the century. Geoengineering is the new twist in this story and will be a key element — for good or bad — in decades to come.

Special note: Journalists, be forewarned. There's a site called Go Bluebird which purports to be a company developing a geoengineering technology. It's a fictional product of the Australian Broadcasting Corp., though it's based on real science. The network calls Go Bluebird an "online alternate reality drama exploring the contentious issues of geoengineering, whistleblowing and philanthrocapitalism." A real-looking blog and tweets are part of this drama.

Cheryl Hogue was recently assigned to cover geoengineering for Chemical & Engineering News. There, she shares the climate change beat with SEJ member Jeff Johnson. Eli Kintisch reviewed this article for scientific accuracy. His clarifications are greatly appreciated.

* From SEJ's quarterly newsletter SEJournal, Summer 2010 issue.




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