In a speech on May 19th, Tim Flannery reportedly proposed, as a last-ditch solution, the mass depositing of sulphur into our atmosphere to reduce the amount of sunlight hitting the earth, thus counter-acting the greenhouse effect of increased amounts of CO2 in the air.
The speech so far seems to have mainly attracted short and negative responses from Australia’s blogosphere (see Andrew Landeryou or Graham Young) though Robert Merkel gives him some credit for at least running the ‘our doom is approaching’ message here.
Two issues in that speech merit careful consideration. One is the set of reasons that climate scientists like Flannery now have to be more alarmist than they were 5 years ago, and the second, more important issue, is that we are finally getting some eminent non-economists who are starting to become aware of the political and economic realities of this world and are starting to take this on board in their public pronouncements regarding climate change management. Below both issues are explored in detail.
The reasons for greater hyperbole amongst climate scientists are interesting and I agree in principle with Don Aitken that concerned citizens should try as best they can themselves to try and get on top of these issues rather than just take them on faith, so below is my attempt at getting on top of the ‘new worries’ (a nice interview on the options, again by Flannery, is here).
One source of increased anxiety is the fast melting of the North Pole. Whilst this wouldn’t increase sea levels, it is the case that water reflects less sunlight than snow and hence having sea at the North Pole rather than snow and ice would further accelerate global warming. What is convincing about this argument is that it appears that a melting of the North Pole hasn’t happened in the last million years, which means it apparently isn’t the case that this is something we have already experienced on a regular basis in human history. What bothers me a little about this argument is that this development is often mentioned in the same breath as the possibility that the Northern Gulf Stream would come to a halt, making Northern Europe much colder. Would that mean a re-freezing of the North Pole and less Global Warming I then wonder? Anyway, I suppose it on balance seems a strongly plausible possibility that makes me interested in the next reports on the North Pole. If this year, which is apparently quite a cold year, sees a record freezing of the North Pole we can sleep easier on this one.
The second source of greater worry amongst these climate scientists is the whole business of masses of methane locked at the bottom of the ocean in the forms of clathrates that would release itself if the oceans would hot up enough, leading to a dramatic increase in the amount of greenhouse gases into the atmosphere. This historically appears to have been associated with temperature jumps of up to 10 degrees! My understanding of this possibility was that it would take a couple of degrees increase in the temperature of the ocean floor to kick-start this cascade, which can’t happen in a hurry because it takes a long time for the ocean floors to heat up, but once it is in motion is almost impossible to stop because of the strong effect on global temperatures of the sudden release of methane. This has happened in the past and the earth apparently does recover from it, but there’s no doubt that a sudden increase in the temperature by 10 degrees would be hard for agriculturale to adjust to overnight. This appears to be the main mechanism climate scientists worry about when they worry about a ‘trigger’ temperature beyond which the worlds’ climate changes much more rapidly than hitherto. I guess on this one the main question outstanding is how much warmer the ocean floor has to get for the cascade to take place and how long it would take to reach that trigger at current trends. I haven’t seen an authoritative answer on that one, but there might be one.
The final reason for increased anxiety appears to be a negative feedback effect of increased CO2 in the atmosphere itself on the aridity of key regions, mainly the Amazon. The usual scenario is that the world will wittness more rain in total because with higher temperatures comes higher amounts of ocean evaporating into clouds. Also, the usual argument on more CO2 in the atmosphere is that this is effectively a fertiliser that makes plants grow faster with less rain needed. Both effects combined would normally be thought of as increasing agricultural production and, on balance, welcome developments. But now there is this negative scenario that has to do with precisely this fertilisation effect: if plants can get the CO2 more easily out of the air, they breath out less moisture (the way they ‘get’ CO2 is by ‘giving’ water). For the Amazon this means that less water is soaked up by the trees and then released again into the air. The water just runs away into the rivers without being re-absorbed into the atmosphere and falling down somewhere else again as rain. In this way, even though there would be more rain near the coast and trees would need less water, it is possible that far upstream there is much less rain such that trees there start dying off, leading to less rain downstream too such that we’d end up having rainforests only near the ocean but not far into the South American interior like we see at present. This rain feedback effect appears to be very important for the Amazon system, to the extent that it is even thought possible that the Amazon might turn into a semi-desert. In itself, the collapse of the Amazon is not an immediate threat to human civilisation even though it’s an obvious disaster for biodiversity. But it would mean a massive amount of additional CO2 being released and not re-absorbed, hence again leading to a feedback loop towards greater warming.
All three of these seem eminently reasonable arguments with logical chains of thought. The last one is a little bit of a ‘theoretical’ possibility in the sense that the strength of the feedback loops in the Amazon are very hard to empirically establish, let alone model the impact of changes on it. Yet I see no inherent reason to distrust the science on this and hence if Flannery and co tell me these things are about to happen then I give it a reasonable chance they indeed will happen.
Then onto the issue of solutions.
The most positive thing about Flannery’s speech is that he is starting to explicitly think of climate engineering as the way forward. This is a very helpful and welcome development, even though he still qualifies it in terms of ‘last-ditch solutions’ and ‘unknown risks’. As I have argued for a long time here and elsewhere (here and here for instance), the only politically feasible solution to climate change is the type of climate engineering that can be unilaterally implemented. World-consensus type arrangements that require serious sacrifices by many of the world’s poorest countries are pipe-dreams that are so politically unrealistic that it’s amazing they ever made it onto the agenda in the first place. The free rider problem in consensus solutions is so obvious that any child can see it won’t happen without some kind of world police which in turn is not free of its own worries (see here).
I sincerely hope that Flannery’s new-found realism will generate a serious debate amongst engineers as to the cheapest and least risky possibilities for reducing the world’s temperatures. It would be great to see them presenting their various plans to us. Perhaps someone will propose a fleet of reflective balloons? Others might venture we should make coal-powered stations dirtier rather than cleaner to get at additional dimming? Perhaps another can think up a space reflector?
I am quite ready to believe most of the existing plans (and none of the ones I mention above are new) will be shown to be infeasible, silly, extremely costly, and even more dangerous than global warming. But having them in the open allows a proper debate about what we can actually do and hence gives an avenue for real hope. That is far preferable to the rain-dance we currently seem to be doing around emission trading schemes.
Just to drive home once more how utterly politically unrealistic it is to expect us to seriously reduce greenhouse emissions in short time-intervals: whilst the federal budget promised paltry expenditures into fossil-fuel reduction schemes of the order of a couple of hundred million, the Queensland government in the same month unveiled a plan for 5 billion dollars to build great tunnels in order to accommodate MORE fossil fuels to be burnt by cars. That plan, by the way, is bad economics for other reasons (i.e. the public-private partnership scheme which basically means over-pricing in the future). But the point here is that this plan is just one of many infrastructure plans that are predicated on the expectation of more carbon transport needs in the future. Also, the pre-election plan to spend 100 million in Brisbane on new bike lanes seems to have quietly left the table after the election.
Hence anyone who watches the hand of government rather than its mouth can’t fail to notice that we are getting ready for more carbon consumption, not less. Indeed, the federal opposition’s post-budget plan to reduce excise on fuel should be read for what it is: a political judgment that the majority of Australian voters care much less about global warming than the amount they have to pay at the pump. Call me a market-economist, but I tend to take such policy-market signals seriously as indications of the true preferences of the population. It is really refreshing to see a climate scientist who starts to openly think about actual solutions, however uncertain and risky they are, rather than just kicking the dead horse that was and is Kyoto and its stable-mates.