Climate engineering, or geoengineering, refers to the deliberate and large-scale intervention in the Earth’s climatic systems with the goal of reducing the effects of global warming. While I would argue that mitigation and fossil-fuel emissions reductions should be the primary course of action on climate change, it is also undeniable that achieving concerted and coordinated political action has been monumentally difficult. As outlandish as some geoengineering proposals may sound, changing the behavior of billions of people and overcoming the basic political and industrial challenges of drastically reducing fossil fuel consumption may prove to be even more difficult.
Although significant progress has certainly been made globally in the areas of renewable energy generation, energy efficiency, and improving transportation efficiencies, the international community as a whole has thus far failed to design and agree upon policies that will drastically reduce the amount of CO2 released into the atmosphere in any climate-impactful way.
More Research Needed
This lack of progress on climate change through emissions reductions leads to the conclusion that other approaches should at least be considered and adequately studied to determine efficacy. In early February, a panel of scientists at the National Academy of Sciences released a report arguing that more research on geoengineering needs to be conducted in order to better understand the associated risks and potential benefits. President Obama’s science advisor also publicly backed the initiative in 2010.
There are at least seven geoengineering proposals that are currently being hypothesized as potential climate intervention strategies:
- Spraying sulfate aerosols into the atmosphere: While risky due to possible ozone layer deterioration, the idea is to reduce the Earth’s absorption of sunlight (much like ash from volcano eruptions).
- Trapping CO2 in carbon scrubbers: Researchers at Columbia University are working on a carbon scrubber that would remove 1 ton of CO2 from the atmosphere per day. Projected to be available in 2 years, such scrubbers would cost $200,000 apiece, according to the Columbia scientists.
- Fertilizing trees with nitrogen: This would theoretically increase the trees’ ability to absorb CO2.
- Aerial Reforestation: Battling rampant deforestation, and the resultant loss of CO2 absorption capacity, airplanes would drop tree seedlings encased in biodegradable containers over large areas of land.
- Adding powered limestone to the oceans: Such schemes would attempt to reduce ocean acidity and increase carbon sequestration.
- Ocean iron fertilization: This process would increase the rate of photosynthesis in phyto-plankton in order to absorb more CO2.
- Enriching soils with biochar: Biochar, a fine-grated charcoal that is highly resistant to decomposition, would hypothetically enrich soils and soak up excess CO2.
This is by no means an exhaustive list of proposals; reflecting sunlight back into space and many other ideas exist. However, it should be noted that there are also many legitimate controversies around geoengineering proposals. Spraying sulfate aerosols into the atmosphere, for example, could degrade the ozone layer. Many of the proposals are too expensive, and most offer an imperfect fix–even if the global average temperature of the earth is reduced, nothing would be done to stop the other consequences of fossil fuel burning such as ocean acidification and air pollution.
While no one knows for sure which geoengineering proposals offer the most promise, I would argue that they should at least be more openly debated and further researched as a possible climate solution (particularly for a crisis situation where the reduction in CO2 needs to be immediate). Unfortunately, the international community has thus far made very little progress in addressing one of the world’s most serious problems, and in the case of climate change, we are in no position to reject promising ideas out of hand.