Why not just blow up the moon?  Make a ring around the Earth like Saturn.  It would be permanent, reduce high tides in a rising sea level, and deplete nuclear waste.

I will miss the moon.

..sound tailor-made for disaster capitalism, which is the one and only reason I fear that, as patently insane and reckless as it is, it might actually be tried even as all civilian infrastructure rots and famine reaches pandemic levels.

The core objections to this are the same as they've always been, and they are irrefutable.

First, the precautionary principle. Even though we are assured that "the less-favorable aspects are also fairly clear", and what's listed as these unfavorable aspects...

likely damage to the ozone layer (as happened after Mt. Pinatubo); the potential for health and ecological damage should the sulfate injections fail to reach the stratosphere; and a temperature "spike" if sulfate injections are stopped abruptly.

..are bad enough, we still have no idea that these wouldn't be just the tip of the iceberg.

Second, we are basically in a species civil war over two ways of conceiving and acting upon our gaiacidal rapacity. One is to repent, pull back from the brink, devolve consumption and the machine, and learn to seek happiness and love rather than gluttony and violence.

The other is to continue the onslaught for all it's worth. This includes all Tower of Babel technofixes which try to have it all, rampant consumption and "green"-friendliness.

Aggrofuels, GMOs, geo-engineering. Three (engineered) peas in a pod. I don't know which is the worst, but these are three absolute threats to the ecological and human future.

Just as with GMOs and aggrofuels the green and humanitarian talk is just talk, so it is with geo-engineering. The real projects will of course be so large and require so much capitalization that massive public monies will be needed to get them off the ground. (If sulphate injections or cloud-brightening really are cheap, they'll either be massively porked up, or else won't be the projects of choice. There's a reason Detroit favored SUVs over small sedans, and it wasn't because SUVs served any real purpose.)

And although the author disparaged his own speculation on military applications as "paranoid", he knows of course there's nothing paranoid about it. Wanting to use weather modification for military purposes has been the main driver of all government meteorological research funding since the fifties. Deep down all they've ever wanted to do is build a weather machine.

So here as elsewhere we see the carbon disaster shock taking shape: the crisis will be used as the pretext for a redistribution of wealth from the public to large private structures, and for the development of new weapons.

That's what geoengineering's all about.

Luckily, the idea's so top-heavy, so high-maintenance, requires such a large fossil fuel platform, would require such extravagant initial capital outlays, that with the steadily eroding world economy and Peak Oil at the door, I'm not too worried about any real attempt being made.

Russ wrote: "Aggrofuels, GMOs, geo-engineering. Three (engineered) peas in a pod". You make a good disater-capitalist critique... except that it is independent scientists who are exploring geoengineering and not profit-seeking corporations (for the most part).

From my perspective, what needs to happen to save the planet is a massive shift away from private power towards global governance. We can surely subject governments and public servants to oversight and accountability. But without a strengthened United Nations and a committment of all people and governments to put aside their narrow self-interest and instead use the various global eco-crises as opportunities to shed child-like animosities, we surely have little chance.

So in my view, if the IPPC or a similar panel recommended stop-gap geoengineering experimentation, and if global governance democratically agreed, then I would support the "best science". Not uncritically. But with an eye to what poses the least harm to future generations.

The European Union alliance of ocean scientists, Eur-ocean have done a number of tests and found iron in the ocean is not practical or really feasible at a scale to make it effective.

how viable are 'soft' geoengineering schemes designed for managing albedo (specifically in urban environments) such as planting millions of new trees and repainting roof surfaces white or green?

would these efforts simply be too little too late even if widely adopted?

they certainly don't carry the same risks as some of the other options.

I don't see any problems with albedo modification or biochar sequestration as they're both fully reversible

"Soft" geoengineering should definitely be pursued, but its impact may be limited. Biochar sequestration and even air capture of CO2 (if viable) are probably inevitable, but as Jamais points out, even if we began doing this on a massive scale, we've signed ourselves up for several decades more warming. As for painting roofs white, well, there simply aren't enough roofs for that to have much effect. It might have limited local effect in very large cities, but most studies that have seriously considered it have dismissed it as ineffective.

"I'm going to tell you something I probably shouldn't: we may not be able to stop global warming. We need to begin curbing global greenhouse emissions right now, but more than a decade after the signing of the Kyoto Protocol, the world has utterly failed to do so. Unless the geopolitics of global warming change soon, the Hail Mary pass of geoengineering might become our best shot." --Bryan Walsh, Time Magazine, 17 March 2008

Any carbon diet strategy would be dependent upon clean coal:

"The vast majority of new power stations in China and India will be coal-fired; not "may be coal-fired"; will be. So developing carbon capture and storage technology is not optional, it is literally of the essence." --"Breaking the Climate Deadlock," Tony Blair, June 26, 2008

But, Vaclav Smil, an energy expert at the University of Manitoba, has estimated that capturing and burying just 10 percent of the carbon dioxide emitted over a year from coal-fire plants at current rates would require moving volumes of compressed carbon d ioxide greater than the total annual flow of oil worldwide -- a massive undertaking requiring decades and trillions of dollars. "Beware of the scale," he stressed."

There is a cheap and simple way to immediately cool down the Earth: just add a little sun dimming aerosol to the upper atmosphere.  By the way, rather than sulfate (like volcanos spew), an engineered sun dimming aerosol could be much more efficient (according to "The Incredible Economics of Geoengineering").

Furthermore, there is a practical mechanical method of remove CO2 from the ocean (ocean acidification is another effect of elevated levels of CO2 in the air):

"Researchers at Harvard University and Pennsylvania State University have invented a technology, inspired by nature, to reduce the accumulation of atmospheric carbon dioxide (CO2) caused by human emissions.  By electrochemically removing hydrochloric acid from the ocean and then neutralizing the acid by reaction with silicate (volcanic) rocks, the researchers say they can accelerate natural chemical weathering, permanently transferring CO2 from the atmosphere to the ocean. Unlike other ocean sequestration processes, the new technology does not further acidify the ocean and may be beneficial to coral reefs. The innovative approach to tackling climate change is reported in the Nov. 7 issue of the journal Environmental Science and Technology..." --"Engineered weathering process could mitigate global warming," EurekAlert, 7 Nov '07

The Greens' resistance to geo-engineering sits very uncomfortably with its message that the planet is screwed and we're all going to die. It suggests that Environmentalism has less to do with saving the planet than it does with reining in human aspirations. It suggests that they don't actually believe their own press releases, and that they know the situation is not as dire as they would like the rest of us to think it is. And that Environmentalists are cutting off their noses to spite their faces - "we'll save the planet our way or not at all." It suggests that Environmentalists regard science and engineering as the cause of problems, and not the solution. --Climate Resistance, Mar '08

While I advocate the short term (cheap and simple) method of putting a small amount of sun dimming aerosol into the upper atmosphere to mitigate rapidly rising greenhouse gas levels in the air, virtually the only long term solution is to remove the excess CO2 from the air.

It can be done either mechanically or biologically.  Currently, because it would be a gigantic logistical task in both energy and resources, mechanical sequestration (and storage) of the excess aerial CO2 is impractical.  Therefore, it must be done biologically.

Currently, the life sciences is undergoing an explosion of knowledge which is called the "Genomic Revolution."  I explain it by saying mankind is "eating from the Tree of Life" (there were two trees in the Garden of Eden-the Tree of Knowledge (which Adam and Eve ate from) and the Tree of Life).  Our knowledge of the genes and how they work is expanding analogiously to the electronics revolution, and will probably eventually have more impact upon our lives than computers.

In my opinion, we should find the best genetic template (in my opinion it is jellyfish) and modify it to remove the carbon from the air and put it into the geosphere long-term.  A GMO seeded into the ocean would multiply geometrically, so it is logistically feasible.  Such an organism couldn't evolve naturally (that would take too long to explain in this format), so mankind would have to create it.

For those who would rather die than seed a GMO into the environment, I guarantee you that we will be routinely doing so to boost agricultural production in an attempt to avoid wide-spread famine.  For those who would rather die than seek a geoengineering solution-we are already using geoengineering to warm up the Earth (albet unintentionally).  For those how think it is beyond mankind's capability to create such an organism that I've briefly described, I suggest you rethink your limited understanding of the genomic revolution.

I will make the following outrageous claim:  if the genomics revolution isn't used to aid the world of microorganisms to collapse human civilization, it will be used to remove the excess CO2 from the air.  Frankly, eating from the Tree of Life is much much more important that almost anyone realises currently.  It is the only true solution and it is the main threat to the true solution.

Its obvious to anyone that, for a given temperature reduction, reducing emissions is wiser than geo-engineering, and no sane person would suggest geo-engineering instead of emission reductions.

It should also be obvious to everyone that we won't reduce emissions to the point where there is no effect on the climate (its a bit late for that).

So the only question is whether some mitigation by geo-engineering is better than none.  There will be undesirable side effects, but not acting also has effects - its a bit late for trying to prevent climate change altogether, so comparing geoengineering to a perfect world is irrelevant, its not a choice we get to make anymore.

It also seems clear that we don't know enough today to start geoengineering; but that's what research is for.

So for the few of you... save your venom for those who don't care about the planet, not those trying to figure out what options we have to minimize the damage.