Geoengineering: Risks and benefits

Model cloud whitening ship Cloud-whitening - geoengineering, or not?

Few issues arouse as much controversy in environmental circles these days as geoengineering - "technical fixes" to tackle climate change, by sucking carbon dioxide from the air or by reducing the amount of sunlight hitting the Earth.

And here's why.

If Planet Earth is facing a climate "emergency", as some people believe we are, then we should leave no option for combating it unexplored, they argue.

While very few scientists advocate deployment of geoengineering now, many believe we ought to be getting on with research now in order to have technologies ready in 10-20 years when they might be needed.

On the other hand, many environment groups and some scientists argue that diverting attention and research funds towards geoengineering means people will take their eyes off the more important tasks of reducing greenhouse gas emissions and adapting to climate impacts.

Some also argue that politicians and the public will see geoengineering research going on and believe it constitutes a "get-out-of-jail-free" card, reducing the incentive to cut emissions.

Add in the fact that the easiest technical fixes might constrain temperatures but won't tackle the problem of ocean acidification, and you have a rich cocktail of scientific, economic and social issues to discuss.

The arguments were on display this week in a symposium at Oxford University, which recently set up a multi-disciplinary research programme on the issue.

Infographic The SPICE test would have pumped out water droplets 1km above the ground

Present were not only physical and social scientists but officials from government departments and funding agencies, representatives from environmental groups and a few journalists.

The hottest current issue in UK geoengineering is the SPICE project.

Its most obvious component, the deployment of a tethered balloon to disperse water into the air, was postponed and probably cancelled earlier this year when some of the team found out that a patent had been lodged on some of the technology.

What was most interesting in the SPICE-related discussions, however, was the question of whether the balloon should be deployed or not.

It's basically a technology test. Researchers want to gather data that could potentially be used in future to make much bigger systems capable of spraying tiny sulphate aerosol particles into the upper atmosphere, mimicking the cooling effect of volcanic eruptions.

The team, led by Matt Watson of Bristol University and Hugh Hunt of Cambridge, have repeatedly stressed that they don't advocate doing this yet and perhaps never will advocate it; they just want the technology to be ready in case it's needed.

Clearly, the SPICE balloon itself would have no climatic impact. Even so, a number of environmental groups lobbied against the research, for reasons enumerated above, with one, the ETC Group, dubbing it the "Trojan Hose".

They and others advocate a tough international regime for all research that would permit laboratory studies but prevent anything happening in the real world.

Others say that's far too draconian, and point to what appears to be the self-contradictory stance of some groups opposing genetically engineered crops - to say there's no research proving they're safe, but then to trash research projects that could provide the proof.

GM protestor Could geoengineering research be blocked, even when it might prove safety?

For example, it was pointed out, spraying sulphate particles into the stratosphere might ruin the ozone layer. You'd want to know that before you contemplated using the technology; but how are you going to find out unless you spray a little bit?

Some rules already exist.

By far the most researched technology is ocean fertilisation, where iron is used to stimulate plankton growth in the ocean, increasing uptake of carbon dioxide. Something like 12 large-scale projects have been carried out, with mixed results.

From the regulation point of view, it's also the most advanced field, with the London Convention having agreed rules in recent years that restrict research on the basis of its potential utility and potential risks.

Commercial interests are forbidden, countries must "use utmost caution and the best available guidance to evaluate the scientific research proposals to ensure protection of the marine environment". Deployment - as opposed to research - is not allowed.

Elsewhere, the UN Convention on Biological Diversity in 2010 agreed that for now, "no climate-related geoengineering activities that may affect biodiversity take place... with the exception of small scale scientific research studies... and only if they are justified by the need to gather specific scientific data and are subject to a thorough prior assessment of the potential impacts on the environment".

The ETC Group and others describe this as a "moratorium" on geoengineering. But it isn't a complete one, as much geoengineering research, even on a large scale, would have no impact on biodiversity...

... whereas climate change, of course, will.

Graphic of warming planet Some argue failure to constrain carbon emissions mean we will need "tech fixes" soon

If the situation weren't complex enough, another issue's arisen lately - what you might call "dual-use" research.

More than 10 years back, I talked to a US scientist just back from an iron fertilisation experiment who explained that personally, he wasn't interested in geoengineering; really, he wanted to answer more academic questions about iron distribution in the water and derive answers about what the oceans used to look like in the past.

He dressed the funding proposal up in geoengineering language because that was the way to get funds - a tactic scientists in all fields have used down the years in order to ensure their research happens (witness the boom in "bioterror"-related research after the US anthrax scares of 2001).

Fast-forward to the present, and we're seeing the opposite phenomenon - research that could give geoengineering answers, but isn't labelled as such.

Last year, US scientists ran a project on the behaviour of aerosols in clouds.

Such research is standard; what was new about the E-Peace project was the inclusion of "controlled release and atmospheric distribution of three different size ranges of [aerosol] particles in flight and on or by a dedicated ship".

Geoengineering research by another name?

Now, a UK team is proposing "seeding" clouds out at sea to control hurricane strength, and perhaps stop them forming at all.

Clouds would be sprayed with minuscule droplets of seawater. This would make them whiter so they reflect more sunlight back into space, reducing the sea surface temperature - which is the primary driver of hurricanes.

Other researchers, including the UK's Stephen Salter, are proposing using the same apparatus to whiten clouds in order to reflect sunlight and cool the world; in another word, geoengineering.

So when some argued in Oxford that research should be constrained if it's tailored towards geoengineering but permitted if it's not, I wondered: how?

What you might regard as an optimistic note is the degree of thought and debate that's going into the issue of how to regulate geoengineering research before it happens.

Nothing like this went into other controversial but important issues such as genetically engineered crops, shale gas or nuclear power before it began.

But whatever rules are eventually developed, one suspects they're going to have to be applied with common sense.

In 1997, while making a radio series on climate change, I went to a roof-whitening ceremony in Miami.

Attended by marching bands and flags and encouraged by a district mayor, the good burghers of several streets were painting their roofs white, to reflect sunlight and cool the Earth.

They were deploying geoengineering. As far as I know, the world is still turning.

Richard Black Article written by Richard Black Richard Black Former environment correspondent

Farewell and thanks for reading

This is my last entry for this page - I'm leaving the BBC to work, initially, on ocean conservation issues.

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  • rate this

    Comment number 97.

    53.Math Man
    11 Hours ago
    @50 Entropicman
    I get about 180 PetaWatts

    I am not reassured. As a civilization , our record when handling high energies is deplorable. Now we are deliberately trying to change the energy budget of a planet.

  • rate this

    Comment number 96.

    Whenever I need a good laugh, warmists are always there to remind me that while intelligence may have limits, stupidity is boundless.

    I really enjoy these ludicrously unsophisticated and poorly thought out solutions to non-existent problems.

    As someone who takes great pleasure in irony there is very little that is a satisfying to me as seeing educated people behaving like chimpanzees

  • rate this

    Comment number 95.

    I can't imagine how the bathtub and balloon experiment would work. You'd need a pressure of 100 atmospheres to push water to 1km above ground. Use a crop duster instead - it's cheap and fast. The problem I have with geoengineering is that it's not even engineering; no one seems to care about the feasibility or the resources needed to implement the schemes.

  • rate this

    Comment number 94.

    IMO geoengineering is nothing but snake oil, a real and simple solution would be to reforest much of the unused land in urban areas the countryside.

  • rate this

    Comment number 93.

    92.Drunken Hobo
    OK I meant the volume has increased 0.009%
    39% (alarmisim %) of nowt it nowt if you see what I mean.

    "current warming is far beyond its capabilities"
    New studies emerging all the time.
    Just read UV from sun affects a lot more than thought previously
    (Sorry dont have a link) & we've had an awful lot of output I believe over the last number of years

  • rate this

    Comment number 92.

    88 PEARL - It's not a 0.009% increase, it's a 39% increase, or an increase from 0.028% to 0.0395%. And remember that O3 makes up far less of our atmosphere, yet has a huge effect.
    89 Earth's orbit around the Sun is well known & predictable for 1000s of years. We know the effect it has on climate, and current warming is far beyond its capabilities.
    I took a guess about the glaciers, just as you did

  • rate this

    Comment number 91.

    All I will say on the matter is, can we breathe water? No we cant and that is what will happen very soon if nothing is done for our childrens survival.

  • rate this

    Comment number 90.

    @87 "Computer modelling can land a car on Mars. To call it "guessing" is somewhat spurious."

    Who called landing a car on mars guesswork?

    I was talking about climate sensitivity - the computer models guesses are way out according to observational evidence

  • rate this

    Comment number 89.

    87.Drunken Hobo
    86 - If you are proposing the recession and growth of glaciers is cyclic, then what mechanism drives it?
    "Orbit around the sun ?"
    But one data point from one location based on a picture taken 80 years ago is fairly insignificant. It could just have been a particularly warm year when the photo was taken.
    It would take more than one year for glaciers to receed that far.

  • rate this

    Comment number 88.

    @82 even if you gave a link to the evidence.. and had Al Gore confirm in a written answer, they would still mark your post down, because it goes against their religion.

    Dont be so hard Perhaps some people are sensitive to the 0.009% increase in Co2 levels in the atmosphere, just like some have nut allergies.
    But it would be a difficult thing to prove without long term tests.

  • rate this

    Comment number 87.

    85 MangoChutney - Computer modelling can land a car on Mars. To call it "guessing" is somewhat spurious.

    86 BLACK_PEARL - If you are proposing the recession and growth of glaciers is cyclic, then what mechanism drives it?
    But one data point from one location based on a picture taken 80 years ago is fairly insignificant. It could just have been a particularly warm year when the photo was taken.

  • rate this

    Comment number 86.

    84.Drunken Hobo
    Woooo...Calm down.. who arguing !
    Mealy pointing out that military pictures taken of Greenland in 1923 or 32 recently discovered in Sweden show the ice melt even lower than now.
    Then I presume it recovered. Cyclic ??
    Make your own mind up and you telling me of "overwhelming evidence" one way of the other doesn't cut it.
    That would be climate fascism
    I'm only stating facts

  • rate this

    Comment number 85.

    @84 And the correlation between CO2 and temperature rise doesn't prove anything either. Nor does ice melting.

    Read up on climate sensitivity and then explain how observational evidence is incorrect and computer guesses are correct

  • rate this

    Comment number 84.

    81 BLACK_PEARL - Even if your claim is true, you are aware it doesn't actually prove anything? No-one claims that all glaciers everywhere are at their lowest ever, or that they couldn't have been lower in the past. The status of a few glaciers in Sweden doesn't disprove the overwhelming evidence for climate change.
    Your arguments are getting weaker. Akin to those used by YouTube creationists.

  • rate this

    Comment number 83.

    @82 even if you gave a link to the evidence, instructions on how to open the link and had Al Gore confirm in a written answer, they would still mark your post down, because it goes against their religion. I use "religion" in the same way that Bain et al (published in Nature) use the term "religion"

  • rate this

    Comment number 82.

    -3 already
    buts its true look it up

  • rate this

    Comment number 81.

    78.Michael Reid
    If anyone is in doubt about "something needing to be done" .

    Yesterday the Arctic ice extent dropped to its lowest recorded level and looks set to drop much further.

    Why this is not the major headline on all the news agencies is mystifying.
    Maybe because its all happened before.
    Pictures from Sweden taken in 1923 show glaciers etc further back than what they are now.

  • rate this

    Comment number 80.

    Stop messing around with things like geoengineering. The systems involved are all much to large to be influenced this way; in any case our understanding of how these systems work is so limited that any intervention is as likely to cause more problems as anything because of unknown feedback mechanisms. Excess global population is the real problem, I think.

  • rate this

    Comment number 79.

    @78 OK, I'll repeat: "Melting ice is caused by more than just temperatures Ocean currents, wind etc affect ice melt."

    See NASA

    "Arctic storms such as this one can have a large impact on the sea ice, causing it to melt rapidly..."

    Read the whole thing for yourselves

  • rate this

    Comment number 78.

    If anyone is in doubt about "something needing to be done" look at the websites; Japanese aerospace exploration agency or the American national snow and ice data centre both of which track Arctic ice extent.

    Yesterday the Arctic ice extent dropped to its lowest recorded level and looks set to drop much further.

    Why this is not the major headline on all the news agencies is mystifying.


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