Efforts to reduce carbon dioxide emissions may not work quickly enough to head off dangerous temperature increases. An additional approach to changing the planet’s climate may be needed. Engineering of the planet’s atmosphere may be how global warming has to be attacked according to one chapter a recent report.
Geoengineering efforts could go in one of two directions, removing CO2 from the atmosphere or reflecting sunlight so it doesn’t add energy to the Earth’s atmosphere.
The United Nations Intergovernmental Panel on Climate Change (IPCC) is looking at the role, if any, that geoengineering should play in government efforts to control global warming.
Russia wants more emphasis to be placed on geo-engineering techniques. A recent document prepared for an IPCC meeting in Berlin pushes that approach. Because Russia is a major oil and gas producer any efforts to reduce CO2 emission could threaten their economy.
The IPCC report mentions removing CO2 from the atmosphere and storing it underground. Russia also wants the IPCC to look at other options, like placing mirrors in Earth orbit or covering certain surfaces in reflective materials.
Supporters of geo-engineering solutions express doubts about either capturing CO2 or reflecting sunlight. Steve Rayner, co-director of the Oxford University geo-engineering program stated that there is considerable uncertainty about such options but that it would be worthwhile to research geoengineering options to see which might be useful.
The IPCC draft report does state that efforts to cut CO2 emissions would have to be cut much faster than is currently projected. Otherwise, some form of CO2 scrubbing would be required to prevent a dangerous temperature increase.
Geoengineering technologies that might help in the latter case either do not exist or are still experimental. Those technologies include spraying clouds with seawater and pumping gases into the atmosphere, to mimic volcanic eruptions.
Humanity has several options for attacking global warming with engineering efforts. In addition to seeding clouds, covering land with reflective materials, and mimicking volcanic eruptions, scientists have conceived different ways to sequester carbon in the ground, or in plants.
One geoengineering technology is being tested on a small scale. Bio-energy with carbon capture and storage, BECCS, works by growing crops that capture CO2, burning the plants to generate energy, and capturing the CO2 emitted. That captured carbon dioxide would be stored deep underground.
Worldwide, human activity produces about 30 billion tons of CO2 per year from fossil fuel combustion.
A Department of Energy study begun in 2009 is testing BECCS. The project is expected to capture one million tons of CO2 per year until the project ends in 2016. The carbon dioxide is captured from an ethanol plant and stored 7,000 feet underground. The project, in central Illinois, is one of several that have been implemented, and the only such project in the United States.
A scientific report from the IPCC states that BECCS could be useful for slowing the buildup of CO2, but only if deployed on a large scale. That scale of deployment would come with risks, such as negative impacts on food crops and earthquakes, and would call for a massive investment.
Aside from being experimental or only theoretical, those technologies bring unknown risks. The ozone layer might be damaged, exposing the Earth’s surface to increased ultraviolet radiation. Weather patterns might change in undesirable ways.
Lord Nicholas Stern, author of a 2006 report on climate change, is one of many who point out the importance of technological innovation in fighting climate change. In a recent interview Lord Stern noted that technology, including renewable energy innovation is critical to avoiding a huge economic hit from the effects of global warming.
While other measures are considered or implemented, engineering might also be needed to attack global warming. Several options exists, and one major challenge that lies ahead is the evaluation of those engineering options to see which if any should be implemented.
By Chester Davis