I disagree with just about everything Professor Haigh is reported as saying and whilst agreeing with some of Ben's text there are some statements that cannot be allowed to stand without challenge.
Prof. Haigh first:
“My first reaction to the whole thing is to say “get real”. The problem of global warming is emissions of CO2, so do something about it....”
Yes of course the problem is caused by emissions and yes we must do something about it. The problem with that approach is that after 14 years (Kyoto 1997) of trying emission reduction measures have not only failed to reduce CO2 emissions they have failed to prevent emissions increasing. Last year CO2 emissions were the largest ever (30.6 Gte). While some countries, notably the UK and EU, have tough targets for future emissions other countries are highly unlikely to match these targets. Even if the whole world adopted, and achieved, the UK's 4th carbon budget target (50% reduction in CO2 emissions by 2025) the world would be 0.32W/m2 warmer and temperature in the Arctic 0.5ºC higher than today (Global emissions would fall to about 14 Gte CO2/y by 2025. Mean emissions per year = (30.6 + 14)/2. Current rate of warming = 0.032W/m2 per year. Increase in warming = 0.032 x 14 x (30.6 + 14)/(2 x 30.6) = 0.32 W/m2.)
Many scientists and engineers, Including the I.Mech.E. [1], have concluded that geoengineering is necessary. They advocate its use in combination with reduction of GHG emissions.
Professor Haigh is clearly unaware of the urgent problem of the rapid shrinking of Arctic sea ice. Because of the poleward transport of heat temperatures in the Arctic are 2 to 3 times the global mean temperature rise. This is already triggering two powerful positive feedbacks: albedo shift in the Arctic sea and release of methane from melting permafrost. A number of scientists are concerned about this and believe that geoengineering is the only means to cool the Arctic quickly enough to avoid a large temperature increase. Retreat of the Arctic sea ice in Summer has increased by 26% n the last two decades and to a greater extent than predicted by IPCC [2].
Thus we cannot wait for the slow response of the world community. While the ultimate solution has to be the complete elimination of emissions it will be of no help if it arrives several decades too late.
“You can see geoengineering as the devils answer – what it does is give you an excuse to carry on burning greenhouse gases, using geoengineering as a palliative.”
No doubt some vested interests might use it this way, but, so far as I know, none of the proponents of geoengineering think this way. Emission reduction must continue. What geoengineering can do is to halt global temperature rise for a number of years, allowing the many alternative and nuclear energy projects in the pipeline to come on line and allow the targets of avoiding the Arctic positive feedback and the longer term target of 2ºC temperature rise to be achieved.
Surely it is not beyond the wit of man to prevent corporations expanding fossil fuel burning, by legislation or taxation.
“If you increase the nutrients for the plankton they can be more efficient in eating up the CO2. Ocean acidification is a big problem with increased CO2...”
Agreed. This may be a valid reason for rejecting this solution but not valid for rejecting all of them.
“Like a lot of geoengineering, it's easy in principle but a lot more uncertain in practice.”
Not true for the best solutions. Sulphate dosing of the stratosphere for example would use well tested existing technology to produce and deliver the sulphur, operating in its geoengineering guise in the same way it has been for many years. It is true that all the possible side effects of geoengineering are less predictable. That is also true of emission reduction. Computer models show that large quantities of sulphur can distort weather patterns. It is also obvious that global warming will distort weather patterns making some parts of the world wetter some dryer and most more prone to severe storms. Distortions due to geoengineering can be avoided, or at least minimised, by using several solutions together at modest levels that allow monitoring and reversal. See also the footnote on Royal Society. And replies to Ben's statements.
“Is it actually morally right for humans to think they can effect the natural systems?”
Humans are already affecting natural systems by uncontrolled emissions. That is why Arctic sea ice is shrinking. The increased energy in the climate system due to global warming will increase the frequency and severity of storms, floods and droughts. Geoengineering seeks to undo man made distortions of the natural world.
“We can't ignore it any more and should participate in the science, even if it's to show that it is not going to work. But we should delay actually building these things.”
This sounds like giving us an excuse to continue the status quo, using uncertainty as the reason for no action. I wish we could spend more time researching the effects of geoengineering but the problem will not wait.
Ben's Statements:
“SRM, for example, would only paper over the cracks in terms of solving the problem of global warming.”
No. Geoengineering is being proposed only because emission eduction has failed. SRM is not cosmetic. It will not hide cracks but it will prevent them from growing.
“And what if a radiation management scheme had to be withdrawn rapidly because of unintended or negative consequences?”
Firstly there is no reason to suppose that a properly designed and distributed system would fail. Secondly if the system is sized to be effective for global cooling in the present (this decade if not sooner) it needs to be little more than 10% of the systems reviewed by the Royal Society. If, for example, a sulphur system of this size, despite being geographically, administratively and technically distributed, were to fail the subsequent temperature rise would be small and slow - 0.03ºC after 6 months [3].
“There may be problems with geoengineering schemes that are very difficult to predict.”
Agreed. However, there are at least 11 geoengineering solutions each with different characteristics and effects. If we use 3 or 4 of the best at a very low level we would minimise adverse effects and disruption caused by problems of delivery with any one of them. See also the footnote.
Footnote:
The Royal Society report on geoengineering [4] has, in my view, done a disservice to the battle against global warming. Taking sulphate dosing of the stratosphere as an example, the report sets preconditions which lead to concerns over the consequences of system failure and adverse effects on weather patterns. These preconditions are the injection of an arbitrary and unnecessarily large quantity of sulphur – sufficient to reverse a doubling of the CO2 concentration, and a failure to properly design the system. It has been shown that these same preconditions if applied to the most popular emission reductions scheme (wind power) would show it to be dangerous and probably impossible [5]. Sulphur dosing at 10% of the level used in the report would give a global cooling of 0.37 W/m2 (sufficient to reverse the global warming due to the next 12 years of CO2 emission at the present rate), and therefore sufficient to bridge the gap between the rhetoric of emission reductionist and the achievement. It would at the same time reduce the adverse affects on weather patterns and concerns over system failure.
References:
- Climate Change. Have We Lost the Battle? I.Mech.E. Nov. 2009
- NSIDC analysis 2010
- Draft Design Criteria for a System to Deliver Sulphur to the Lower Stratosphere. Baglin April 2011
- Geoengineering the Climate. The Royal Society. Sept. 2009
- Letter to Chris Huhne. Baglin 24/07/2010
Colin Baglin
Next letter: Erroneous statements