by a siegel
Thu Mar 6th, 2008 at 04:55:09 AM EST
In the face of the potential for catastrophic climate change and global warming, "geo-engineering" is an arena getting a little attention and some press, such as W Broad, NYT Times
Geoengineering is the deliberate modification of Earth's environment on a large scale "to suit human needs and promote habitability".
One can argue that all efforts to control carbon emissions (to reverse past emissions) falls within GeoEngineering, but that is not the general context of consideration, which often focuses on efforts that would, somehow, have a direct impact on Earth's temperatures (and not, necessarily, on carbon loads).
One step back question, which does not necessarily seem to occur in many conversation, is what principles should guide Geo-Engineering efforts and prioritization of their potential.
Diary rescue by Migeru
Some thoughts as to principles
The core principle should be: win-win-win. A proposal that, in a systems of systems effort, provides multiple wins and does not solely address temperature. Thus, a proposal that offers real potential for improving economy, reducing carbon, and contributing to reduced temperature (both directly, somehow, and indirectly through reduced carbon loads or carbon capture) would seem to merit greater prioritization than high-cost efforts that would solely impact "temperature" but not impact (or worsen) the carbon load equation.
Risk factors must be placed into the equation. How "known" are the system-of-system implications? Does it create other problems while "solving" (or ameliorating or delaying) temperature challenges?
And, can the response be done quickly, affordable, and in a distributed fashion?
These seem to be some questions that can be asked to see whether 'win-win-win' is possible.
Looking at options: Five "traditional" proposals
Wikipedia provides five examples of GeoEngineering
- Mirrors in space: with the purpose to deflect a percentage of solar sunlight into space, using mirrors floating around the earth.
- Stratosphere sulfur-spraying: with the purpose to modify the earth's albedo with reflective or absorptive materials spread over portions of its surface.
- Nourishment: with the purpose to fertilize the ocean with iron to encourage algae growth.
- Cloud-seeding: with the purpose to spray seawater in the atmosphere to increase the reflectiveness of clouds.
- Artificial Trees: with the purpose to suck carbon out of the atmosphere.
While each is interesting (even intriguing) in its own way(s), these seem to (across the board) fail the "win-win-win" equation process (although, to be honest, the artificial trees are rather interesting to consider). The space mirrors would be tremendously (prohibitively) expensive and do nothing about carbon loads (and, potentially, actually worsen them). The Sulphur risks more acid rain for a limited gain in slowing warming trends. The Iron Seeding seems to have limited results in testing and has uncertain long-term prospects. Cloud-Seeding, again, is a net carbon cost (the energy to run the system) with some uncertainty over the impact. Each of these merits more attention than one summary paragraph can provide, but to summarize: these are not win-win-win strategies.
Do Geo-Engineering Win-Win-Win Spaces Exist?
Okay, I've set out a few ideas on principles, created a challenge. Is it a challenge that can realistically be met. Simply put: yes! Here are several paths to help contribute to dealing with temperature levels that go to a positive space in other arenas.
Reflective Roofing: A typical 'asphalt' shingle/such roof, with a very low albedo factor (reflectivity) absorb substantial amounts of solar radiation through the year. Shifting to a reflective roofing material can send much of that solar radiation back to space. It is also highly cost effective because it can reduce air conditioning loads and increase roof longevity. Some payback analysis suggests that, when compared to 'traditional' roofing, reflective roofs can pay back the added cost in just a few weeks. Now, what about the heat/cooling impact globally?
The Earth has an albedo of 0.29, meaning that it reflects 29 per cent of the sunlight that falls upon it. With an albedo of 0.1, towns absorb more sunlight than the global average. Painting all roofs white could nudge the Earth's albedo from 0.29 towards 0.30. According to a very simple "zero-dimensional" model of the Earth, this would lead to a drop in global temperature of up to 1 °C, almost exactly cancelling out the global warming that has taken place since the start of the industrial revolution. A zero-dimensional model, however, excludes the atmosphere and, crucially, the role of clouds. [But!] It would be interesting to see if more sophisticated models predict a similar magnitude of cooling.
As much as 1 degree centigrade via white roofing! Perhaps it is time to start changing building codes and reflecting some sun back to space. And, remember, this will lower carbon loads through energy efficiency and reduced roofing replacement requirements in out years. And, another win element: this can be done by almost any organization, any government, any individual ... now. And, they will save money while helping to save the planet's habilitability.
Permaculture: We can reclaim deserts through inexpensive but quite thoughtful practices, reducing the heat loads in these areas, capturing carbon, and fostering economic activity. Don't believe me? Take a few moments to watch this. Again, this can be done almost anywhere, at low cost with a high benefit. What are we waiting for?
Agrichar / Biochar / Terra Preta: Very simply, we have the potential for a carbon-negative fuel that will, over time, also foster improve fertility in soil. Very simply, gasification of biomass can be combined with agricultural practices to create energy, have the waste plowed back into the soil to improve fertility (while reducing fertilizer requirements), and have some of the carbon from each of these cycles captured in the soil. "[T]he great advantage of biochar is the fact that the technique can be applied world-wide on agricultual soils, and even by rural communities in the developing world because it is relatively low tech." This is a highly promising arena that is getting attention, but perhaps not enough. For some additional discussion, for example, see: Energize America (also); Biochar: The New Frontier; The pay dirt of El Dorado; International Biochar Initiative; Birth of a New Wedge; and Terra Preta for Carbon Reduction.
Roaring 40s: Remember the ice cube being dropped in the ocean to solve Global Warming in Futurama? Maybe this wasn't total lunacy. The Roaring 40s in the southern hemisphere have tremendous wind resources, wind resources that are Stranded Wind. Wind farms, perhaps floating wind farms, can be set up in these great winds to make ammonia to be used for fuel (and perhaps hydrogen and perhaps be used to support industrial processes in these areas). The process of making this ammonia will remove heat energy from the oceans and, voila, contribute to ice formation.
Geo-Engineering is staring us in the face. But, we can pursue "Geo-Engineering" along win-win-win paths, such that they will more than 'pay for themselves' while helping to moderate temperature through the decades (centuries) of abnormally high carbon loads in the atmosphere.
NOTE: Cross-posted from Energy Smart.