Features, Future Please

Future, Please: Geoengineering

January 17, 2014

Earlier this week, Al Gore said it would be “utterly mad” to combat climate change with large-scale geoengineering projects. For what it’s worth, we agree – and the sooner we start, the better.

Why Mess With Mother Nature?

To be blunt, that ship has sailed. Geoengineering might be the only way to stave off dystopia.

Credit NASA GoddardTo avoid massive heatwaves, coastal devastation, starvation, and drought, the Intergovernmental Panel on Climate Change concludes we must hold any mean global temperature increase to 2 C or below. Even half such an increase won’t be pretty, of course – just 1 C will cause a 21% decline in wheat harvests, more powerful storms, flooding, and food insecurity – but more than two degrees puts us in seriously dire straits.

Credit Peter BarrIf we take no action, some models call for almost twice as much warming. For perspective: mean temperatures are roughly that much higher today, as compared to when the Northeastern United States was under three thousand feet of ice.

There are no happy stories along that timeline, unless you fancy a tour of scenic Bartertown or a life hanging on Paolo Bacigalupi’s grim meathook.

Credit abjam77Implementing the more radical emissions reduction proposals in the latest IPCC report gives us a 66% chance of passing a recognizable climate on to our descendents. As instituting even modest reductions is an uphill battle, the odds of prevailing over established interests in contributing industries are not favorable. In China, to pick an extreme example, atmospheric pollution from fossil fuels is over 20 times the safe limit; enough to shorten life expectancies in the capital by as much as 15 years. If effective pollution control is out of immediate reach under totalitarian governance, it seems unrealistic to expect more heavy-handed intervention within democratic societies.

So, indeed, Mr. Gore: a sane and measured response would be ideal, but it may be time to dust off the Crazy Ideas file.

A Modest Geoengineering Proposal

Scientists and engineers have a number of practical geoengineering proposals for climate modification on the books, mostly involving either solar radiation management or atmospheric carbon removal.

Unknown SourceFurthest along of the solar radiation management projects is a proposal to seed the upper atmosphere with sulfate particles – essentially, engineering a never-ending volcanic eruption. (This concept was the particular target of Al Gore’s ire, above.) Sulfate aerosols introduced by natural volcanoes cool the planet rapidly, and by very nearly the margins we’re after – so why not reproduce the effect via controlled delivery?

One of the most vocal proponents of solar radiation management through sulfate dispersal is David Keith, Harvard physicist and author of A Case for Climate Engineering. In his proposal, a baseline of 25k tons of sulfate aerosol dispersed annually through the lower stratosphere could hold warming down to 1 C by the end of the century, if we increase sulfate proportionate to the ongoing warming from existing emissions.

Credit HughhuntAs other scientists modeled the effects of Keith’s proposal, sulfate injection slowly moved from screwball-but-workable towards the planning and testbed stage. The government of the United Kingdom, in particular, is slowly moving forward with practical plans to implement sulfate dispersal, testing candidate particles and delivery mechanisms. The SPICE project (Stratospheric Particle Injection for Climate Engineering) is funded through March of this year and already in the prototype stage.

While most modelers concede that sulfate dispersal would be effective for short-term cooling, there are drawbacks. Yale e360 quotes Keith noting that health effects from resulting air pollution may “contribute to thousands of air pollution deaths a year”, but that’s hardly the beginning. Depending on the speed at which dispersal is pursued, rainfall patterns could be severely disrupted. Droughts and lowered agricultural yields are the most likely – and mildest – second-order effect.

Uncertainty over the utilitarian calculus of solar radiation management lead to such protests that SPICE canceled a prototype test run in October of 2011. The test run – where engineers hoped to investigate mechanical complications introduced by stratospheric wind speeds – involved nothing more controversial than water, but the possibility of advancing geoengineering technology was enough to spark outrage.

One year later, SPICE placed field testing of any sort on indefinite hold.

Such protests could be why a rogue proponent of a second major geoengineering methodology – sequestering carbon in artificially-induced plankton blooms – never bothered to seek approval in the first place.

Trust Me, Salmon Love This Stuff

Pub DomainRuss George approached the leadership council of the Haida nation with a proposal: fund his plan to dump 100 tons of iron sulfate into the waters off Haida Gwaii as part of a “salmon enhancement project”. The iron dust would create an artificial phytoplankton bloom, pulling carbon dioxide from the atmosphere and restoring the health of local salmon fisheries. In time, the Haida could claim and sell carbon credits from the project, through a corporation set up for the purpose. The salmon win, the Haida win, and the health of the ocean is restored.

Just sign here.

What Russ George neglected to tell the Haida before they voted to support his project – or the National Oceanic and Atmospheric Administration, when he conned them out of monitoring equipment – was that he’d tried this carbon credit scheme before. His vessels were banned from Spanish and Ecuadorean ports and the United States warned him not to fly a US flag anywhere near one of his ocean fertilization projects. After being warned that ocean fertilization was permitted only for non-profit experiments, George and the Haida Salmon Restoration Corporation went ahead with a project five times larger than any undertaken to date.

George disputes this version of events, as do prominent individuals within the Haida community. That George sought – and received – additional funding from the Canadian National Research Council and equipment from NOAA under false pretenses is fairly well established, as is the fact that the project was undertaken for profit (both in terms of restored fishing yields and sale of carbon credits). Debate seems to hinge on whose idea this all was and whether or not it worked; a massive plankton bloom did result, but salmon populations won’t be noticeably affected until later this year.

NASAOcean fertilization is not only illegal, but there’s still active debate as to whether it’s particularly effective in the first place for sequestering atmospheric carbon. On the surface, increased phytoplankton activity seems like it should process CO2 out of the atmosphere, effectively sequestering it when they sink to the bottom of the ocean upon death… but how much? Despite claims by George that his team of scientists – none of whom will he identify – ‘collected a “golden mountain” of data on the plankton bloom’, this data has yet to be published for review. One prominent researcher in the field, who HSRC representatives claim was aware of the project, denies he ever heard from them at all.

While plankton seeding through ocean fertilization could work as a form of climate modification, capers like the Haida release only poison the air for legitimate research. What could have been a massive, telling experiment to determine its effectiveness will go down as a titanic, for-profit geoengineering scam.

Geoengineering from Orbit

NASA Earth ObservatoryThere are other proposals – still quite hypothetical – for managing solar radiation through space-based megaprojects. While perhaps the least likely to make it off the whiteboard, this solution class is to be admired for sheer sense of wonder; even the tamest entries call to mind the work of Sax Russell, the astoundingly brilliant engineer and physicist from Kim Stanley Robinson’s Mars Trilogy.

There are three major concepts for blocking a percentage (~1.8%) of incoming solar radiation via space-based “sunshades:” a tremendous diffraction grating, a Fresnel lens 1,000 km across, or a swarm of autonomous spacecraft at L1. Here is a really interesting overview of technical issues relating to the use of a diffraction grating or autonomous spacecraft.

Credit Roger Angel Tom Connors Univ of ArizWhile tremendously expensive, space-based approaches have the advantage of not generating unforeseen ecological complications through the direct manipulation of atmospheric or oceanic chemistry.

They may not address the root cause of climate change, but… autonomous swarms of space robots? Yes, please.

What’s your favorite blue sky geoengineering project? Link us in the comments or @EngineerJobs.