Tuesday, November 4, 2008

Inventory of geo-engineering proposals

Geo-engineering proposals seeking to combat global warming should be assessed according to efficacy, cost, risk, timeframe and the rate at which they can mitigate climate change, says Philip W. Boyd of New Zealand's NIWA in an article published in Nature Geoscience.

We need more thought on whether proposals like carbon burial, geochemical carbon capture, atmospheric carbon capture, ocean fertilization, cloud manipulation, space sunshades, or strategically-placed pollution can be effective on a time-scale relevant to humankind, economical, or even safe.

Meanwhile, AP reports that John Shepherd will head a working group at Britain's Royal Society to study geo-engineering proposals, with a report expected to be published in mid-2009.


Sam Carana said...

It's a good idea to compare the various geo-engineering proposals and to look at the (dis)advantages of each method. In fact, that's the very reason why I started this blog in the first place!

As my late father once said, many years ago: "If only all nations had a common enemy; the joint effort to fight such a common enemy would unite all nations and result in lasting world peace." Well, global warming constitutes such a joint enemy; let's fight it!

Back in May 2005, I compared two methods, i.e. releasing dust particles in the air to reflect some of the sunlight, as compared to positioning mirrors in orbit above Earth.

There are a few problems with the dust-particles approach, such as difficulties in regulating the right amount of dust. It may turn out that - in hindsight - too many dust-particles have been released in the atmosphere and that it will be quite a problem getting them out again.

Another problem is that the dust-particles method will affect the climate everywhere on earth.

Mirrors can work much more selectively, preventing sunlight to shine on a desert area and thus making it more habitable, while keeping the climate elsewhere the same as it was. The latter may also be politically more attractive. And while there is also a risk of mirrors taking away too much sunlight, this can be regulated more immediately than trying to take dust particles out of the air.

We need to evaluate each of these methods, using feasibility, effectiveness and cost as some of the criteria. Included in the evaluation should be the measures currently taken by many nations, such as encouraging the use of alternative power sources, such as solar power, wind power, heat pumps, etc.

I propose to evaluate and discuss such alternatives here, as an international effort, in places such as these groups. Sure, there are many academics already studying questions like this and there are many government-appointed committees looking at funding and regulating things. But by discussing alternatives relatively freely in groups like this, we can avoid political and commercial pressure influencing or even determining the outcome of such evaluations.

Many projects have been proposed. Such an ambitious project could capture the eye of the media and the imagination of the public and all who would like to contribute to the project. But as said, a decent evaluation is a prerequisite and any such project should remain one out of many alternative approaches to the various problems.

Political Group at Google

Sam Carana said...

Also note Ken Caldeira's call for a climate engineering research plan, at climate-engineering.blogspot.com

Jim Bronke said...

Shame I didn't find this list years ago. Would have liked to tske these discussions further. It is necessay to compare the approaches for all of the factors mentioned. In 2005 I presented the dust screen idea to a GW Group in Delaware. wish I had heard the concerns. I am not worried about too much dust and too much cooling. When a volcano like Pinatubo blows its top it would be hard to equal such a feat overnight. Pinatubo only succeeded in .5 deg F from what I understand. Lets talk.

Sam Carana said...

Hi Jim, a lot has happened since. See this List of proposed geoengineering projects at Wikipeida and the many posts at the geoengineering group at Google.