CAMBRIDGE, Mass.--A group of academics on Friday considered the ultimate engineering challenge: building machines to stabilize the earth's climate.
The Massachusetts Institute of Technology convened a symposium here to discuss the potential benefits and pitfalls of geoengineering, also called climate engineering. Everything from shooting light-blocking particles into the atmosphere to "artificial trees" is being seriously studied, despite trepidation among researchers and opposition from others.
During talks Friday morning, academics said climate engineering techniques are not well understood and, because of the complexity of the global climate system, individual approaches are pockmarked with uncertainties.
Still, speakers at the event said it's time to step up research in geoengineering to sort out which approaches are worth serious consideration. But they cautioned against expecting easy fixes or abandoning efforts to ratchet down the growth of greenhouse gas emissions in the atmosphere.
"At this point the fear is that if we talk about this, people will stop cutting emissions, which is a rational fear. But the idea that we shouldn't have a research program would be a real mistake," said David Keith, the director of the ISEEE Energy and Environmental Systems Group at the University of Calgary during his talk the symposium, which was called Engineering a Cooler Planet.
Speakers said each climate engineering approach needs to be viewed with an associated cost and risk. For example, one relatively inexpensive idea is to shoot particles, called aerosols, into the air in order to block the amount of heat from the sun that reaches the earth's surface.
The cooling effect from aerosols, such as sulfur dioxide, in the atmosphere is rapid--measured in days or years. But they also impact the planet's water cycle. Early models show that large-scale efforts to inject aerosols in the atmosphere would likely make certain areas drier and affect the monsoons in India and Asia, said Joyce Penner, a professor of atmosopheric sciences at the University of Michigan.
Even with the risks and uncertainties of climate engineering, speakers said that there is risk with the so-called business-as-usual scenario where the concentration of greenhouse emissions continues to increase at its current pace.
These heat-trapping gases in the atmosphere are forecast to raise average global temperatures, speakers said. But there are a number of regional impacts from global warming, which will likely spur more research in planet-level engineering, said Thomas Karl, the director of NOAA's National Climatic Data Center.
For example, higher temperatures directly affect water and agriculture. The productivity and ability to reproduce of common crops goes down after certain temperature levels, Karl noted. Pests have a longer time to populate and weeds grow better with more carbon dioxide, too, he said. The west of the U.S. is already feeling the impact of droughts, which will continue if mountain snowpack decreases.
"It's an important choice to make even if we don't do a thing--that's a choice itself," said Karl. "The consequences of not studying this are enormous--understanding the physical, ecosystem, and societal impacts."
Engineering for a cooler planet
There are two general approaches to engineering for a cooler planet: reflecting sunlight back into space or removing carbon dioxide from the air and storing it.
Injecting sulfur-based aerosols in the atmosphere have a known cooling effect observed in volcanic eruptions, including Mount Pinatubo in 1991. The approach is more practical than, say, placing mirrors in space. But there still isn't suitable understanding of how the entire climate system would react, including potential changes to ocean circulation, ocean ecosystems, and land precipitation, said Penner.
Also, blocking sunlight from space does not address the problems caused by higher concentrations of carbon dioxide on earth, notably ocean acidification which makes it more difficult for marine animals with shells or corals to grow, speakers noted.
(Credit:
Philip Boyd, University of Otago in Dunedin.)
Other approaches for reflecting heat back into space include spraying sea salt from special-purpose boats to enhance the reflectivity of clouds or installing white roofs on buildings to bounce more sunlight back into space.
Land-based approaches to reducing greenhouse gas concentrations include growing algae-based fuels at massive scale, storing carbon dioxide in underground geological formations, and making charcoal with plants to create a soil amendment called biochar.
There have also been 12 tests to stimulate plankton growth by "fertilizing" the ocean with iron. The goal is to create a rapid "plankton bloom" which will remove carbon dioxide and sequester it in the ocean. But this technique is difficult to verify and risks transforming the existing ocean ecosystems, said Tim Lenton, professor of earth system science at the University of East Anglia.
Because of the risk and uncertainly, Lenton said he is not convinced that climate engineering proposals to block solar radiation makes sense. On the other hand, land-based approaches create competition with other uses of land, notably agriculture.
One area that clearly needs further research is the life-cycle analysis of different climate engineering idea, Lenton said. For example, dumping iron into the ocean to grow plankton has an associated carbon footprint.
"You'll find out when you do the full calculation, it's very difficult to make it carbon negative," he said. "Because of the emissions in simply deploying the technology, it will veto a number of options."
The computational models to simulate the regional impact of climate changes need to be improved as well, said David Battisti, a professor of atmospheric sciences at the University of Washington. In research he presented on Friday, Battisti found that once models took into account ice and ocean effects from aerosol injection, there was a significant variation on the projected impact on temperatures and precipitation.
The symposium at MIT is not the first meeting of scientists to consider geoengineering--the idea has been discussed for decades. But some of the academics on Friday said the current trajectory of climate change argues in favor of at least doing research on climate engineering techniques, even if these projects are ultimately never launched.
There is also a uncertainty around climate policy and how effective policies will be at cutting emissions, noted Keith. "It doesn't mean that we have to do it. But it means that you do need to have the capability to do it," he said.
In the near term, research in the field should be focused on ranking different proposals, addressing both scientific and political issues, said Philip Boyd, a professor of ocean biochemistry from the University of Otago in New Zealand.
Boyd has created a model that ranks geoengineering schemes in terms of efficacy, affordability, safety, speed of implementation, and the ability to stop a project. Societal and political factors need to be considered because conflicts over use of land, water, and the ocean creates a "geopolitical mess."
"We pump up the potential for conflict," he said. "It's just a minefield in terms of teasing these apart."
(Credit:
Royal Society)
Geoengineering is not a last resort, but the next necessary step to recalibrate the Earth's climate unless carbon emissions are significantly reduced in the near future, the Royal Society, the U.K.'s national academy of sciences, announced Tuesday.
"It is an unpalatable truth that unless we can succeed in greatly reducing CO2 emissions we are headed for a very uncomfortable and challenging climate future, and geoengineering will be the only option left to limit further temperature increases," John Shepherd, chair of the Royal Society's geoengineering study and a professor of Earth system science at the University of Southampton, said on behalf of the group.
The report "Geoengineering the climate: Science, governance and uncertainty" (PDF) urged carbon emissions reduction as the primary means of halting climate change. But it looked at geoengineering--engineering the environment on a large scale to purposely manipulate the world's climate--very seriously.
In past years, geoengineering has been thought of an as option of last resort, but the Royal Society asserted that some of the safer geoengineering techniques, like aggressively planting forests, could be implemented currently in conjunction with carbon reduction efforts.
Since geoengineering has the potential to affect people on a global scale, the group further recommended that an international organization like the U.N. Commission for Sustainable Development begin developing policies and a means for resolving anticipated geoengineering political conflicts.
"Assuming that acceptable standards for effectiveness, safety, public acceptance and cost were established, why should appropriate geoengineering options not be added to the portfolio of options that society will need and may wish to use to combat the challenges posed by climate change?" said the report.
With that in mind the group evaluated the safety, expense, effectiveness, and quickness of deployment for projects falling under two main classes of geoengineering: carbon dioxide removal (CDR) and solar-radiation management (SRM).
CDR, efforts to remove greenhouse gases from the atmosphere, included things like afforestation, encouraging plankton growth, and carbon capture and storage in the form of burying carbon-rich biomass or using biochar for fuel.
The SRM suggestions for manipulating the Earth so that it absorbs less solar radiation included more seemingly far-out options like painting all roofs white to reflect sunlight, placing thousands of space mirrors in near-Earth orbits to reflect sunlight, and spraying aerosols into the stratosphere.
The group said it generally favored CDR projects over SRM because they involved processes closer to natural occurrences, while the side effects of SRM projects are unknown and therefore more dangerous.
London, if it gets an algae-growing makeover.
(Credit: Institution of Mechanical Engineers)The future of green technology is algae-cultivating buildings, artificial trees, and lots of white roofs, according to the U.K.'s Institution of Mechanical Engineers.
The group on Thursday released a report that recommends governments fund research on geoengineering, or large-scale fixes for climate change. The report, a year in the making, is targeted at policymakers and is meant to inspire engineers to develop ways to cut greenhouse gas concentrations in the atmosphere.
As concern grows over climate change, a number of geoengineering ideas have been proposed, including placing mirrors in space to reflect sunlight or shooting sulfur particles into the stratosphere, which would also have a cooling effect.
However, in its analysis, the Institution of Mechanical Engineers found that most promising geoengineering techniques can be done on Earth. It argues that a handful of technologies be deployed at large scale, along with other strategies, to mitigate the effects of climate change.
At the top of the list are artificial trees, which are mechanical devices that can absorb carbon dioxide from the air faster than trees and then sequester that gas underground.
The institution's report refers to the research done by Columbia University Professor Klaus Lackner, who is researching the concept and materials to absorb large amounts of CO2. Also required are underground storage formations, such as depleted oil wells. At a cost of $20,000 per tree, the institution concludes that it's the most practical approach.
Cultivating algae to make liquid fuel is one of the most active areas of research in biofuels. The institution recommends that algae be incorporated into buildings so algae can be grown at a large scale.
How artificial trees, which capture carbon from the air, could be deployed alongside wind turbines.
(Credit: Institution of Mechanical Engineers)Engineers envision that long plastic tubes, called photobioreactors, be integrated into building designs or retrofitted onto existing skyscrapers.
Algae would grow from pumped-in carbon dioxide and sunlight and be harvested for use either as a liquid fuel to run in a combined heat-and-power unit or turned into biochar, or charcoal used as a soil conditioner that also sequesters carbon from the air.
Finally, the institution says that buildings should be retrofitted with reflective roofs to deflect the sun's rays. In the past months, U.S. Energy Secretary Steven Chu has publicly touted this relatively low-tech approach, which was studied in-depth at the Lawrence Livermore Laboratory last year.
Although proposing billions of white roofs doesn't appear to be controversial, many other geoengineering ideas are. For example, scientists have warned about the environmental impact--or effectiveness--of "seeding" the ocean with iron to spur growth of plankton to sequester carbon.
In anticipation of a report on geoengineering from the U.K.'s Royal Society next week, watchdog ETC Group warned against unintended consequences from large-scale projects. "Even the most careful computer models won't be able to predict what will happen if an experiment is scaled-up and moved out of doors," the group said in a statement Friday.
An ancient technique to fertilize soil by creating charcoal from plant waste is being revived to tackle some of today's environmental problems.
The latest company to pursue manmade charcoal, called biochar, is Biochar Systems, which has developed a biochar-making machine that can be pulled by a pickup truck. Two customers--a North Carolina farm and the U.S. Bureau of Land Management--will be begin testing the units this fall.
The unit, called the Biochar 1000, is designed to convert woody biomass, such as agricultural or forestry waste, into biochar, a black, porous, and fine-grained charcoal that can be used as a fertilizer. It uses pyrolysis--slowly burning biomass in a low-oxygen chamber--to treat 1,000 pounds of biomass per hour, yielding 250 pounds of biochar.
The Biochar 1000 converts agricultural wastes to charcoal, which is then added to soil, a process that enriches soil and removes carbon from air.
(Credit: EcoTechnologies Group)There still isn't a well established market for selling biochar, but there's growing interest among researchers in the process as a way to cut greenhouse gas concentrations. The United Nations has proposed classifying biochar as a carbon credit for sequestering carbon from the atmosphere.
When forestry or agricultural waste are converted into biochar and put into the soil, the carbon that would have been released through decomposition is held in the soil for hundreds or potentially thousands of years, say proponents.
A number of companies have formed to either create fertilizer or use modified machines to convert biomass into a liquid fuel such as methanol. The first U.S. biochar conference was held in Boulder, Colorado, two weeks ago, organized by the International Biochar Initiative industry group.
Tons of green waste
Biochar Systems, a joint venture created by BioChar Engineering and EcoTechnologies Group, has developed a mobile machine targeted at landowners or other organizations that generate a lot of "green waste," such as agricultural producers, nurseries, or land managers. The biochar can be used on-site as a soil amendment or moved and sold as a fertilizer, according to Fernando Migliassi, chief corporate development officer at EcoTechnologies Group.
The Bureau of Land Management will use one unit, which weighs 4,000 pounds and is 12 feet long, seven feet high, and five feet wide, to improve soil that has been damaged by mining, according to Biochar Systems. The North Carolina Farm Center for Innovation & Sustainability will use test a unit as well to see how agricultural waste can be converted into fertilizer.
The Biochar Systems Biochar 1000 costs $100,000 and is capable of turning out 1,000 tons of biochar a year.
Another unit will be tested by the Colorado State Forest Service to thin forests and treat the tons of wood infested by pine beetle into a soil amendment. Thinning forests manually is very expensive but the biochar machine could be a cheaper route.
"If this is feasible, it would allow us to manage a greater portion of forested lands that right now aren't cost effective," Joseph Duda, forest management supervisor for the Colorado State Forest Service told ClimateWire.
The U.S. produces 368 million tons of forest product waste a year and another 60 million tons a year of wood infested by the pine beetle, according to BioChar Engineering. Having a mobile unit reduces overall pollution as biomass doesn't need to be hauled for treatment at a centralized plant, according to the company.
But although it has potential to mitigate climate change, some people have warned against relying heavily on biochar as a carbon offset. The impact of biochar on land may have changed since the time thousands of years ago when people in Amazon region created charcoal, called terra preta.
"But despite its astounding potential, caution is warranted in implementing biochar on any sizeable scale. Though re-creating terra preta sounds simple, recent research suggests that modern-day soils may respond less well to the treatment and that the carbon may escape sooner than anticipated. On these questions alone, all of the evidence is not in," according to a recent editorial in the journal Nature Reports Climate Change.
A new idea for storing carbon dioxide underground using charcoal, or biochar, is being panned by organizations that oppose large-scale geoengineering projects.
The ETC Group on Monday published opposition to biochar from 147 small environmental and human rights organizations, calling the growing support for biochar a "dangerous new false solution to climate change."
Manmade coal produced by Carbonscape's Black Phantom machine.
(Credit: Carbonscape)Making charcoal--also called agrichar and terra preta--from organic matter like trees through low-oxygen burning, or pyrolysis, can improve soil while keeping carbon dioxide out of the atmosphere for thousands of years, say backers.
A number of companies are developing methods for making biochar as a strategy to stabilize carbon dioxide levels in the atmopshere. One New Zealand company called Carbonscape is developing a system that uses industrial-size microwave machines to turn wood, trash, and even sewage into biochar.
Carbonscape claims that its machine, called the Black Phantom, will sequester more carbon underground that the carbon dioxide generated for running its machine.
The ETC Group's organizations do not appear opposed to biochar outright. But they are clearly wary of polluters relying heavily on using bichar carbon offsets as a way to comply with carbon regulations.
Some environmentalists are in favor of using charcoal to store carbon underground and improve soil for agriculture--Carbonscape, for example, has some well known climate experts on its board. The warning by the ETC Group, which points to biofuels as an example, is a reminder to proceed with caution and common sense in implementing climate technologies.
Proposals to cool Earth by injecting the atmosphere with sulfate particles would deplete the ozone layer and have "perilous effects" on the planet, according to a paper to be published Friday.
As concerns grow over climate change and global warming, large-scale efforts to alter the planet's climate through geoengineering are being taken seriously by academics.
A proposal to cool the climate with sulfate particles in the atmosphere would further damage the ozone layer, a study concludes.
(Credit: NASA)But a study performed by the National Center for Atmospheric Research (NCAR) cautioned that more research is needed before so-called geoengineering efforts are pursued.
It specifically raised the alarm over the idea of regularly sending sulfate particles into the stratosphere to reduce the Earth's temperature. It's one of the most discussed geoengineering proposals put forth by Nobel laureate Paul Crutzen and others.
"Our research indicates that trying to artificially cool off the planet could have perilous side effects," Simone Tilmes, the leader of the NCAR study, said in a statement. "While climate change is a major threat, more research is required before society attempts global geoengineering solutions."
The cooling effects of suflate particles has been observed from past volcanic eruptions. The eruption of Mount Pinatubo in the Philippines, for example, had a measurable downward effect on temperatures.
The NCAR study concluded that injecting sulfates would destroy between about a fourth and three-fourths of the ozone layer above the Arctic Ocean.
That would delay recovery of the ozone layer hole above the Arctic and thus mark a major setback for international efforts to protect the ozone layer by banning ozone-depleting chemicals. The ozone blocks harmful ultraviolet rays from coming to Earth.
Other geoengineering proposals include putting a shield above Greenland to deflect the sun's rays and stimulating large-scale plankton blooms in the ocean to sequester underwater carbon dioxide.
Academics point out the obvious challenges of these geoengineering ideas, given the complexity of the climate and the prospect of managing such global ventures among different countries.
Climos, a start-up that plans to mitigate climate change by stimulating plankton growth, said on Wednesday that it has raised a series A venture capital round of $3.5 million.
Braemar Energy Ventures led the round, which also included participation from investor Elon Musk, now chairman of Tesla Motors.
As previously reported, the funding will be used to develop and test Climos' ocean iron fertilization technique, in which an iron compound is put into the sea to stimulate the growth of plankton.
As the plankton grow, they take the greenhouse gas carbon dioxide out of the atmosphere. Over time, some of that plankton die and sink deeper in the ocean, thereby storing the carbon dioxide.
Ocean iron fertilization tests have taken place in the past two decades but have not been fully tested as an effective carbon storage technology. Climos intends to make money by selling the sequestered carbon as carbon offsets.
Planktos, a company with a similar business plan, last month folded because of a lack of funding and what it called a "disinformation campaign."
Indeed, the practice of ocean fertilization remains controversial, as it has brought criticism and skepticism from environmental groups.
Climos, staffed by renowned scientists, has called for a code of ethics in doing ocean experiments, saying it intends to work with permitting authorities before doing tests, CEO Dan Whaley said last month.
The company also intends to use the funding to hold a series of scientific workshops in preparation for a demonstration experiment.
In a statement, Braemar Managing Director Dennis Costello said Climos is one of the "most interesting investments in Braemar's history."
"While OIF (ocean iron fertilization) has been well-researched over the past 20 years by some of the world's top scientists, no private company has been able to combine the scientific expertise with the business management skills that Dan Whaley has assembled with his team," Costello said. "They have created a strong business plan for advancing this technology while addressing the questions surrounding it, which led to our funding of the company."
Only a few weeks after ocean iron fertilization venture Planktos folded, rival Climos is set to announce a first round of venture funding totaling $4 million.
Climos CEO and founder Dan Whaley said Thursday that the company will announce funding early next week.
The green area is a natural plankton bloom in Lake Titicaca, South America.
(Credit: NASA)Iron stimulates the growth of plankton, which consumes the greenhouse gas carbon dioxide. Once the plankton sinks several hundred meters, it is considered sequestered from the atmosphere.
The practice of ocean iron fertilization, which has been experimented with since the 1990s, has been condemned by some environmental groups and remains controversial.
Read the full story on Climos here at CNET News.com. For more background on Climos, here is a longer interview with Whaley.
For a while now, I've been reading bits and pieces about the concept of geo-engineering: undertaking macro-scale actions in the atmosphere to counteract the impact of increasing greenhouse gas emissions. From what little I'd read, it seemed like the ideas of crackpots.
That was until my Cleveland Foundation colleague Kathleen Cerveny sent me a most intriguing link to a videoed lecture by David Keith from the University of Calgary on the Web site TED.
No kook, professor Keith argues that it's very possible to inject large quantities of sulfates high above the stratosphere, and in so doing put a brake on climate change far more rapidly than can be accomplished by shifting our energy system to reduce emissions.
In this talk, he leaves unstated the technological approach for accomplishing this task, though he claims, interestingly, that it could be done at relatively moderate costs of a couple percent of world GDP.
He also points out how dangerous this Pandora's box of geo-engineering would be to open. It seems akin to the dilemmas associated with the discovery of how to harness atomic energy: once you know about it, it so profoundly affects the future fate of the human species that it becomes imperative to institute a global approach to controlling this knowledge for the forces of good rather than evil.
Interesting watching; have a look.
Richard T. Stuebi is the BP Fellow for Energy and Environmental Advancement at The Cleveland Foundation, and is also the founder and president of NextWave Energy.
Scientists are starting to consider planet-scale engineering projects to slow the pace of climate change--anything from causing massive plankton growth in the ocean to putting a giant mirror in space above Greenland to stop ice from melting.
These ideas to alter the earth's environment at large scale, called "geoengineering," are increasingly being articulated and seriously evaluated even though they are likely to be controversial.
Earlier this month, climate scientists held a conference in Cambridge, Mass., to discuss the importance of geoengineering projects. The overall consensus was that geoengineering deserves further study, according to one of the organizers and news reports.
Beyond that general agreement, though, there was a wide diversity of views on the potential effectiveness of these proposals and the impact they could have on how people address climate change, according to a report in Science magazine. Some feared that geoengineering could dampen efforts to address global warming in other ways, such as using less energy and investing in renewable energies.
One of the summit organizers is Harvard University Professor Daniel Schrag, a geochemist who studies climate changes over the Earth's history. Last Wednesday in Cambridge, he gave a brief outline of some of the techniques being considered and his feelings on the subject during an MIT Enterprise Forum on energy.
Most of all, Schrag is scared of the risks that undertaking these projects pose.
"We don't understand the climate system very well and so trying to engineer a system that is probably unknowable and almost certainly uncontrollable is a very frightening thing," Schrag said.
Large-scale geoengineering concepts go back decades but they appear to be gaining more currency as concerns about global warming heighten. During a presentation, Schrag noted that greenhouse gas emissions over the last two years have been higher than the "business as usual" scenario created by the Intergovernmental Panel on Climate Change.
"This may be a terrible idea but it might be better than the alternative, which is to let greenhouse-gas forming run away," he said.
Capturing carbon
Some efforts led by commercial companies are already going ahead.
Planktos and Climos are two companies that intend to "seed" the ocean with iron to stimulate the growth of plankton. During a plankton "bloom," or large-scale growth, plankton metabolize carbon dioxide.
The idea behind these ocean fertilization companies, which have already been sharply criticized, is that plankton growth can sequester large amounts of carbon dioxide in the ocean. Planktos, which launched its vessel from Florida earlier this month, has said it intends to sell carbon credits for the captured carbon dioxide.
Although not generally considered geoengineering, another technology being seriously pursued is carbon capture and sequestration at coal-fired power plants.
The U.S. Department of Energy is sponsoring a project called FutureGen to build a power plant with integrated sequestration and hydrogen production.
Commercial efforts are now getting started as well, although financing them is a significant hurdle, according to Phillip Boyle, president and chief operating officer of Powerspan. The company has developed scrubbing technology, now in testing, that it says removes 90 percent of carbon dioxide from coal power plants, along with other pollutants.
Other carbon-sequestration plans call for pumping carbon dioxide under the sea.
Artificial volcanoesSchrag mentioned other approaches being considered, including releasing sulfur into the atmosphere in an attempt to mimic large volcanic eruptions. When sulfate aerosols are released into the atmosphere, they cool the climate; the eruption of Mount Pinatubo in the Philippines had a measurable downward effect on temperatures. Sulfur could act as a "crude" substitute for sulfate aerosols, he said.
"You could get more technical and actually put in things that are more sophisticated than sulfur that actually would hover over Greenland and reflect light away from Greenland to keep the ice sheet from melting," Schrag said. "All these ideas are actually being discussed."
Another concept put forth by Columbia University Professor Klaus Lackner is making artificial trees that would be designed to capture carbon dioxide from the air.
Apart from the technical challenges and environmental risks, geoengineering poses difficult questions over control.
"This is exactly the opposite of greenhouse gas reductions. Greenhouse gas reductions--we can't do it alone. We can do it but we need everybody to do it--China, India, and Europe and Russia and lots of other countries to participate," Schrag said.
"With climate engineering, we're not the only ones that can do it. There are any one of 25 countries that could do it. Who gets to control it? Who gets to decide?" he said. "This is a really scary thing."
- prev
- 1
- next
