the next step: carbon-negative?

According to the IPCC, we need to cut our CO2 emissions by about 80 percent in order to avoid the worst impacts of global warming. At this point, however, we are on much different pathway, according to the same report:

"The IPCC Special Report on Emissions Scenarios (SRES, 2000) projects an increase of global GHG emissions by 25 to 90% (CO 2-eq) between 2000 and 2030, with fossil fuels maintaining their dominant position in the global energy mix to 2030 and beyond. More recent scenarios without additional emissions mitigation are comparable in range."

How are we to reduce the amount of greenhouse gases in our atmosphere, when projections show that we are only continuing to increase our rates of emitting them? We won't be able to prevent disastrous climate changes by only reducing our emissions (driving less, converting emissions back into synthetic gasoline - as described in the Feb. 19th post on this blog). Also, it would be next to impossible to achieve carbon-neutrality for every industry in the world; given that reality, we must find a way to draw down CO2. According to The New York Times, the inevitable answer is that businesses and industry will have to achieve more than carbon-neutrality; some will have to go beyond that goal to become carbon-negative.

How could this work? One method would make use of technology we have already created. As described in the February 15th post on this blog, we currently have the technology to sequester the CO2 produced by coal-fired power plants, by storing it in underground wells. This process is carbon-neutral, since coal originated underground. In other words, we dig up carbon (in the form of coal) that has already been sequestered underground by natural geologic processes, derive energy from it by burning it, and then we return the carbon back underground. Hence the process is carbon-neutral as far as the atmosphere is concerned. In order to make this to a carbon-negative process, we can instead burn plant matter or biomass. In this scenario, plants and trees take carbon out of the atmosphere through photosynthesis, the plants are harvested and burned for energy, and the carbon released by this burning is stored underground, in the same way described for coal emissions.

Other technologies described by Matthew Wald in the NY Times are more complicated. One idea would use the technology already in place of removing CO2 from the air as it passes through smokestacks, but instead of relying on smokestacks, this process would:

"[use] waste heat from a solar plant, which has no smokestack... the relatively small amount of waste heat from a solar-generating plant could do the job. They estimate that they could remove about five pounds of carbon dioxide per kilowatt-hour of electricity produced. (A coal plant emits about two pounds when it makes that much electricity.)"

How brilliant! By using the waste heat derived from producing renewable solar energy, CO2 emitted from non-renewable, dirty sources can be cleaned up from our atmosphere. This and other technologies aimed at a net reduction of greenhouse gases from the atmosphere pose the only realistic and meaningful methods for preventing global climate change. In some senses, working towards carbon-neutrality is only spinning our wheels... so to speak.