Science/Environment Deliberately cooling the Earth

[pmad87]

I've heard a couple of things in the last month about using various substances to cool the earth rather than focusing only on emissions reduction which is going to take a long time to work and needs every country's support. It sounds like the kind of thing the Right should be pursuing rather than continuing with crackpot explanations of why global warming is a lie.

I found this article from a couple of years ago about pumping sulphur into the upper atmosphere:

http://news.bbc.co.uk/2/hi/programmes/6369971.stm

There was also an article in The Age a little while ago about how the people at NASA who look at terraforming Mars have been asked to look at applying some of their technology to Earth in order to cool the planet.


I can imagine that in opposition to this, hardline conservationists will go on about unforeseen consequences and how we will only be further changing the planet for the worst, but:

1. This is not the 1850s. As much study of possible and probable effects will be done.

2. Even if there are unforeseen consequences, we will come up with something to deal with them too. We've been adapting to changing environments for 1000s of years, and we'll be doing it for another 1000 years.

 

[bit_pattern]

Geoengineering is at best a last ditched measure to try and shield ourselves from the worst excesses of climate change, but it is not a solution. For instance, you might be able to spray sulfates into the atmosphere and get a 25 year pause in warming, but as GHG's continue to build up in the atmosphere then the moment the sulfates clear you are likely to cop 25 years of warming in a single whammy. Not to mention the unknowns about spraying sulfates into the atmosphere or seeding the ocean with iron, we could well create an entirely new catastrophe. There are some good articles on the weaknesses of geoengineering, I'll try to dig them up when I get a moment.

 

[Ice-Wolf]

I propose giant air conditioners. Now we just need to find a way to bleed the heat generated by them into space, but that can't be too hard can it?

Or we could just make up massive CO2 scrubbers like those used on the Space Station, that'll work won't it?

 

[bit_pattern]

As the following articles suggest, it probably isn't a very good idea to engage in large scale planetary experiments when we only have one planet. If something goes wrong, and it easily could, then we'd be ****ed.

Geoengineering in vogue

Would it work? In most of the cases under discussion the target is the global mean temperature, and so something that balances the global radiative forcing of greenhouse gas increases is likely to ‘work’. However, having no global mean forcing is not the same as having no climate change. A world with higher GHGs and more stratospheric aerosols is not the same as a world with neither.

Thus there will be side effects. For the stratospheric sulphate idea, these fall into two classes – changes to the physical climate as a function of the changes in heating profiles in solar and longwave radiation, and chemical and ecological effects from the addition of so much sulphur to the system. Physically, one could expect a slight decrease in surface evaporation (a ‘dimming’ effect) and related changes to precipitation, a warming of the tropopause and lower stratosphere (and changes in static stability), increased Eurasian ‘winter warming’ effects (related to shifts in the wind patterns as are seen in the aftermath ofvolcanoes). Chemically, there will be an increase in ozone depletion (due to increases in heterogenous surface chemistry in the stratosphere), increases in acid rain, possibly an increase in high cirrus cloud cover due to indirect effects of the sulphates on cloud lifetime. Light characteristics (the ratio of diffuse to direct sunlight) will change, and the biosphere may react to that. Dealing with the legal liability for these predictable consequences would promise to be a lively area of class action litigation…. On the positive side, sunsets will probably be more colorful.

Could it keep up? GHGs (particularly CO2) are accumulating in the atmosphere and so even with constant present-day emissions, the problem will continue to get worse. Any sulphates put in the stratosphere will only last a couple of years or so and need to be constantly updated to maintain concentrations. Therefore the need for the stratospheric sulphates will continue to increase much faster than any growth of CO2 emissions. This ever-increasing demand, coupled with the impossibility of stopping once this path is embarked upon is possibly the biggest concern.

Climate change methadone

A wider range of people have now started to publish relevant studies – showing clearly the value of continued research on the topic – and a key one came out this week in JGR-Atmospheres. Robock et al used a coupled GCM with interactive aerosols to see what would happen if they injected huge amounts of SO2 (the precursor of sulphate aerosols) into the tropical or Arctic stratosphere. This is the most talked about (and most feasible) geoengineering idea, based on the cooling impacts of large tropical volcanic eruptions (like Mt. Pinatubo in 1991). Bottom line? This is no panacea.

Figure 1: Results from Robock et al showing the imapct on temperature of their scenarios.

So what are the problems? Robock’s study looks at a subset of the potential ones – in particular, the impacts on precipitation. These arise because evaporation is more sensitive to changes in solar radiation than it is to long-wave radiation – so increasing LW and decreasing SW (as you would have in a geo-engineered future) gives a net reduction in evaporation even if the temperatures stay pretty constant. In the experiments they report on, there is a substantial reduction in rainfall in the northern tropics (especially the Sahel and the monsoonal belts). This is actually quite a robust result: reductions in tropical precipitation were reported in simpler tests of this idea in papers by Matthews and Caldiera and Bala et al.

Figure 2: The impact on precipitation in the geoengineered case compared to the control (no GHGs or geoengineering).

From Nature: On ocean fertilisation.

It is already commonly accepted that ocean iron fertilization should not be rushed into as a mitigation strategy. The Intergovernmental Panel on Climate Change regards it as supported by neither appropriate assessment of environmental side effects nor a clear institutional framework for implementation. Similarly, last year, two United Nations conventions passed resolutions restricting large-scale ocean iron fertilization activities, citing concerns about the environmental risks and lack of a scientific basis on which to justify such activities — concerns that have been recognized for some time. A Royal Society report released this month emphasized that the technique has a relatively small capacity to absorb carbon, and comes with “probably deleterious ecological consequences”.

Yet concerns about the profound consequences of global climate change have led to calls (see, for example, K. O. Buesseler et al. Science 319, 162; 2008) for field studies of iron fertilization on larger and longer scales. Although we agree that the kinds of experiments being promoted have more to teach us about ocean processes, we argue that they will not resolve any remaining debate about the risks of iron fertilization for geoengineering. Engaging in experiments with the explicit purpose of assessing iron fertilization for geoengineering is both unnecessary and potentially counterproductive, because it diverts scientific resources and encourages what we see as inappropriate commercial interest in the scheme.

 

[cancat]

You can move to Siberia if you want, the rest of us will just reduce CO2 emissions.

I don't believe it will be necessary. But for those who are concerned, like the OP seems to be, I was just proposing that moving people is an easier solution that dicking about with the atmosphere.

Richard Lindzen seems to agree.

http://www-eaps.mit.edu/faculty/lindzen/L_R-Exchange.pdf

the fact that we already have three-quarters of the climate forcing expected from a doubling of CO​

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2 means that if one truly believes the models, then we have long since passed the point where mitigation is a viable strategy. What remains is to maximize our ability to adapt. However, the promotion of alarm does not follow from the science...​

 

[pmad87]

It looks like the science is still in its infancy. But it definitely seems worth pursuing. In the OP I was thinking more that pushing this kind of response to global warming would be better for the Coalition than the current mess they are in.

 

[bit_pattern]

Don't speak for me, brother. I'll take warm showers when I want and travel overseas when I can. If I were serious about reducing emissions I would do neither. Thus you can deduce I couldn't give a stuff about my CO2 emissions.

No one is asking you to forgo those luxuries, mate, just that we heat our hot water with renewable energy and that our aircrafts be fueled with algal biofuel or the like. I like hot showers and overseas travel too, with a bit of luck I'll be in Africa in the next couple of years. GW is too big of a problem to be solved by individual efforts, it requires sound public policy initiatives so that we can all live happily and sustainably.

 

[Geelong_Sicko]

Six multi-megaton airbursts somewhere over each of the seven continents. Nuclear winter for the win

 

[bit_pattern]

I don't believe it will be necessary. But for those who are concerned, like the OP seems to be, I was just proposing that moving people is an easier solution that dicking about with the atmosphere.

Richard Lindzen seems to agree.

http://www-eaps.mit.edu/faculty/lindzen/L_R-Exchange.pdf

It's comments like that that make Linzden a laughing stock in the scientific community. He just can't let go of the fact that his cloud cover hypothesis was so soundly disproved.

 

[bit_pattern]

It looks like the science is still in its infancy. But it definitely seems worth pursuing. In the OP I was thinking more that pushing this kind of response to global warming would be better for the Coalition than the current mess they are in.

What would we do about ocean acidification though? Sure, we *could* feasibly implement such a plan but the oceans are going to continue to absorb CO2 and their PH levels will continue to fall and that will potentially be an even bigger problem than GW. If you don't believe in GW then here is an even better reason to reduce CO2 concentrations.

There are also a whole raft of issues such a plan would create; ozone depletion, effects on cloud cover and rainfall, the rapid warming we would experience if the systems failed etc etc etc.

 

[sherrinorburley]

You too can cool the planet, while being cool.
Like these guy's.

http://www.fibrealternatives.com/

Will even grow in Russia.

 

[bit_pattern]

Jack Herer grew some very good weed. I had the privilege of sampling some of the strain that bears his name a few years ago

 

[medusala]

It's comments like that that make Linzden a laughing stock in the scientific community. He just can't let go of the fact that his cloud cover hypothesis was so soundly disproved.

Come off it BP, this has hardly been soundly disproved

Most will admit the effects of cloud cover and water vapour arent fully understood.

 

[Wally Carter]

Welcome to the future.

A nice constant 25C all year round.

 

[sherrinorburley]

I like that going underground idea.

So many wine cellars with massive expansion potential.
People have to get value for their real estate dollar.

 

[evo]

I can see the appeal. Don't bother asking the Mrs for a pool room, or home theatre- just start diggin'

 

[Jafa]

Welcome to the future.

A nice constant 25C all year round.

It is certainly an interesting option. Japan is already planning massive underground cities.

 

[Wally Carter]

Plants can supply all the oxygen, hot water and solar power can be piped down from the surface.

"Sun rooms" for underground gardens and effluent can be broken down to feed plants.

 

[Ripper]

Madness. The earth is already cooling faster than the datasets say.

It has not warmed this century.

 

[Inferno]

How well would they cope in earthquakes though? If Japan is planning them you'd think they'd be fine but are there actually major risks in the event of earthquakes?

 

[medusala]

It has not warmed this century.

Come on Ripper, it has. You just have to be a bit creative.

Use a 100 year moving average for example.

 

[Ripper]

Come on Ripper, it has. You just have to be a bit creative.

Use a 100 year moving average for example.

LOl, How about 5 year moving thermometers?


[youtube]nEiLgbBGKVk[/youtube]

 

[Falchoon]

Speaking of 5 year moving thingies, cooler or warmer could we have a bit more rainfall directed our way please.

 

[bit_pattern]

It has not warmed this century.

That's about the stupidest thing I think I've ever heard you say.

 

[Wednesday]

Come on Ripper, it has. You just have to be a bit creative.

Use a 100 year moving average for example.

My 'trick' to 'hide the decline' is to turn my laptop upside down. It works every time.

Sorry