Will geo-engineering get us out of this mess?

From everything that I have heard this week, even if there is any progress on the rules for implementation of the Paris Agreement (the expected product from COP24), it isn't going to get us closer to achieving a planetary limit of 1.5°C or even 2.0°C warming. To the contrary, the scientist presentations over the past two weeks in Poland have sounded pretty dire, even more so than the gloomy predictions from the IPCC Global Warming of 1.5°C report. The main message: Unless we are able to employ some pretty dramatic technology "fixes", the reductions in greenhouse gas emissions via the collective country NDCs (mitigation goals) will be insufficient in the time frame required to avert serious negative consequences. In other words, a net zero carbon balance between the planet and our atmosphere is not longer good enough. Scientists claim that we need aggressive net negative emissions, and planting millions of trees and restoring mangroves isn’t going to do that for us.

Last night, I had a long dinner conversations with some scientists who believe that carbon capture and sequestration/storage (CCS) is absolutely necessary. Since this will be expensive to employ on a large scale, they were wondering if OPEC would be willing to set oil at $150 - 200 a barrel to cover the cost of CCS. Seeing how people in France are reacting to a fuel tax, this would be politically challenging and have serious impacts on the economy. However, such market pricing could be the needed impetus to boost investment in renewable clean energy alternatives.

When I was in graduate school in the early to mid 1980’s, a number of laboratories were studying the impacts of increasing atmospheric carbon dioxide on plant and algae growth. One idea that was floated at the time was to artificially boost the growth of photosynthetic marine plankton which could, in turn, sequester extra carbon from the atmosphere. At that time, the atmospheric carbon dioxide levels were around 341 ppm; we hit 410 ppm this year. Scientists determined that iron was limiting, so oceans would need to be supplemented with this micronutrient and hence, this idea became known as the Geritol solution. (If you aren't old enough to remember Geritol, you may need to look it up!) We were young and quite naïve about the links between increasing carbon dioxide and climate disruption. Back then, we thought the idea was pretty crazy. We certainly never dreamed of even more science-fiction sounding ideas like trying to artificially control solar radiation through geo-engineering approaches.

Until this year, I had heard little discussion at COPS about the idea of managing solar radiation.  A leading scientist in this field, David Keith from Harvard, was also at dinner. He argued that it is better to do the research now to determine the feasibility and risks of geo-engineering -- before things get desperate and countries start blindly shooting sulfate aerosols into the upper atmosphere to deflect solar radiation without having the data or national agreements to guide such action. As a plant biochemist, this concept scares me. A lot. Deflecting sunlight isn't a particularly good idea for photosynthesis and primary production (think the first level of the global food chain). And we really have no idea whether the sulfate aerosols would remain in the stratosphere. As someone who works at a restoration site where vegetation was killed off in large part due to sulfur dioxide emissions being converted to sulfuric acid in the atmosphere, this idea seems doubly crazy.

But in David's view, it comes down to a question of which planetary experiment we want to run: extreme warming and climate disruption or testing some technology-approaches that may alter our future in very different ways.

Some more reading:

Goodell, J. A Hard Look at the Perils and Potential of Geoengineering, Yale Environment 360, April 1, 2010.

Suarez, P. and K. Maarten. Geoengineering: A humanitarian concern Earth's Future, December 23, 2016