The Best Australian Science Writing 2013 (9 page)

No two researchers are more prone to the special kind of scientific excitement that can possess geoengineers than Stanford climate scientist Ken Caldeira and Pentagon ‘weaponeer' Lowell Wood. Damage to the ozone layer is likely to be one of the side effects of sulphate aerosol spraying, which involves coating the earth with a layer of tiny sulphate particles to block some incoming radiation. This would allow more ultraviolet light to reach the surface, so risking more skin cancer. Caldeira and Wood have an answer. They argue that some kinds of ultraviolet light that cannot be seen ‘may be largely superfluous … for biospheric purposes, and thus portions of these spectra may be attractive candidates for being scattered back into space by an engineered scattering system'. This light is invisible to us, so why do we need it? Particles could be specially engineered to allow through more of some kinds of light than others. They argue that such a scheme could save us US $10 billion a year from avoided skin cancers. An additional benefit of scattering redundant bands of the light spectrum is that the sky could be rendered discernibly bluer.

It is a strange kind of thinking that believes it can identify basic properties of the solar system that are surplus to requirements and may be dispensed with. A different kind of thinking assumes that things are there for a purpose and that the structure of life on Earth as a whole has evolved to fit the environment in which it finds itself. So on closer inspection ‘junk DNA' turns out to be genetic material whose functions we had not yet worked
out. Many insects rely on ultraviolet light for their vision, reptiles need it to bask in and it is essential to production of vitamin D. The multitudes of species on Earth have evolved to manage the potential damage from ultraviolet light. Yet Caldeira and Wood suggest that we can filter out this superfluous form of light, so that we regulate not only the quantity of light reaching the planet but its quality. There is no bridge to cross to engage with this type of thinking. There is only an abyss of incomprehension.

The Promethean plan for ultimate control has been set out explicitly by Brad Allenby, now an engineering professor at Arizona State University, in a strategy he calls earth system engineering and management. He begins with the observation that humans have not merely transformed the landscape but have imprinted themselves on every cubic metre of air and water, to the point where the Earth has become a human artefact. There is no more ‘natural' so we must cast off all romantic notions and take responsibility for conscious planetary management. In a definition whose training manual phraseology says as much about its meaning as the words themselves, Allenby writes:

Earth systems engineering and management may be defined as the capability to rationally engineer and manage human technology systems and related elements of natural systems in such a way as to provide the requisite functionality while facilitating the active management of strongly coupled natural systems.

In case it might be thought that such a vision excludes all that is essentially human, Dr Allenby (who for some years in the 1990s was director for Energy and Environmental Systems at Lawrence Livermore National Laboratory, of which more later) assures us that ethics can be incorporated into his system. It can even encompass ‘religion', while still maintaining the requisite
functionality, thereby granting space for a system-compatible God. To reassure those who fear that managing the Earth system must entail ‘centralized control' or ‘universal mandates', Allenby is certain that engineering an artificial world can be carried out by the free market. Moreover, he writes, Earth system engineering will embody ‘inclusive dialog among all stakeholders' and ‘democratic governance', while at the same time being modelled on ‘highly reliable organizations' such as a well-run nuclear power plant or an aircraft carrier.

It's hard to know what to make of this kind of utopian techno-enthusiasm, except to note that it is very prevalent in the geoengineering community, especially in the USA. It drives Bill Gates, Richard Branson and Nathan Myhrvold and a hundred other techno-entrepreneurs whose understanding of the world has been shaped by the peculiar culture of Silicon Valley. Brad Allenby has more recently shifted his position, tempering his dream of Promethean mastery with a strong dose of political conservatism. Now he argues that climate science is disputable (there is a ‘real controversy' over whether warming is caused by human-induced emissions or changes in solar energy) and that climate scientists do not have the same authority as other scientists. He believes, following standard denialist tropes, that contrarians have been unfairly ‘demonized' and political polarisation is due, not to the efforts of the merchants of doubt such as ExxonMobil and the Tea Party, but to the ‘strident tone' of environmentalists. International collaboration won't work, he believes, but there is little need for it because the prevailing social and economic systems are adapting to climate change (such as it is) ‘remarkably quickly'. No major policy interventions are needed, and that goes for geoengineering too. In short, the system is flexible and its components can adapt to whatever the climate throws at us; the real danger lies in overreacting to the apparent threat. Allenby has joined the small but influential
group of ‘luke-warmists', those who cannot be accused of denying climate science but consistently emphasise the uncertainties, downplay the risks and defend the prevailing order against policies that seem to threaten it.

Other experts with a more clear-eyed view of climate science and its implications are turning their attention to the kind of engineering system that would be needed for managing the solar filter. The Novim Group, a non-profit scientific corporation, identifies five core control variables available for the solar filter or ‘short-wave climate engineering' (SWCE): the material composition of the aerosol particles, their size and shape, the amount dispersed, the location of dispersal into the stratosphere and the sequencing over time of the injections.

The development of a dynamic multivariate control system – incorporating robust monitoring of climate parameters, maximum intervention flexibility and intervention stability – is therefore an important component of SWCE research. Control-system design should pay particular attention to the likelihood of various climate parameter responses including delays, feedbacks, nonlinearities and instabilities across widely ranging temporal and spatial scales.

Temporarily forgetting just why they are detailing Plan B, the authors add that ‘strategic management' of greenhouse gas emissions ‘must be considered a central component' in managing the solar shield. Good luck with that.

The engineers are alert to the fact that installing a planetary thermal control system is not merely a technical problem. They are concerned that unspecified ‘socio-political system failures' – perhaps climate wars, terrorist attacks, changes of government in the USA and social unrest in China – may lead to ‘unintentional disengagement' giving rise to ‘transient oscillations in the
climate system'. Transient oscillations in the climate system may refer to monsoon failure, but the climate engineers are not too worried because ‘disruptions of varying character and scale are common in comparably large and complex technical and socio-political systems'. What were they thinking of when referring to disruptions to comparably large and complex socio-political systems – the Russian Revolution, the Great Depression, the Black Death? Who knows? Even so, any control-system blueprint, they advise, should keep these possibilities firmly in mind.

The Novim experts then canvass the dystopian prospect of ‘counter-climate engineering' – geoengineering deployed by one nation to undo the effects of geoengineering by another. ‘For example, the deliberate injection of short-lived fluorocarbon greenhouse gases might rapidly offset the regional or global cooling effects of a SWCE intervention.' (In the case of marine cloud brightening, the fleet of unmanned ships roaming the oceans would be sitting ducks for a disgruntled state.) Any such contest over global weather could be ‘disastrous', so international governance arrangements should be carefully considered. They finish on an optimistic note, suggesting that ‘once engaged, the maintenance of a SWCE system becomes a permanent bequest to future generations'. A bequest to future generations. Words sometimes fail.

Some of those environmentalists and scientists most acutely aware of the dangers of global warming support geoengineering. Humans have caused such a build-up of greenhouse gases in the atmosphere, they argue, that even radical cuts in global greenhouse gas emissions will not be enough. To render the climate tolerably safe we will need to reduce atmospheric concentrations of carbon dioxide to 350 parts per million or below from their expected peak at 450 ppm (an extremely optimistic target), 550 ppm (optimistic) or 650 ppm (likely on current trends), remembering that the long-term pre-industrial level was 280 ppm. It's
a powerful argument with the best motives. By endorsing geoengineering their objective is not to find a way of defending the political and economic systems from the threat of climate change, but simply to protect us from calamity.

With their high level of understanding of the complexities of the climate system and the risks of global warming, those who take this position tend to favour early deployment of geoengineering because, even with radical abatement measures, carbon dioxide ‘drawdown' will be necessary. So the sooner we start deployment of carbon dioxide removal methods the better. They tend to prefer more natural and local kinds of climate engineering such as reforestation and biochar rather than system-altering approaches such as ocean fertilisation (adding nutrients to the oceans to stimulate algal blooms that can suck up carbon dioxide) or a solar filter. The former are slow-acting methods that would require decades to take full effect and would therefore be of no use as a response to a climate emergency.

The grander climate engineering proposals operate on a scale far larger than previous interventions by humans in environmental systems. Nevertheless, some lessons can be learned from prior attempts to manipulate environmental systems. The history of human interventions in complex ecosystems shows that they frequently trigger a burst of unintended effects. In one case, a freshwater shrimp was introduced into a Montana lake in order to augment the food supply of salmon. However, it was not understood that shrimp feed at night, while salmon feed during the day, so instead of the salmon eating the shrimp, the two species competed for the same zooplankton food source. Instead of salmon numbers multiplying they fell, and so did those of the local eagle population that depended on them for food, undoubtedly with flow-on effects elsewhere. The intervention was a kind of ‘ecological roulette' – spin the wheel and see what happens.

Human interventions have had many successes, but it's
the disasters that we should heed when considering schemes as audacious as some of those proposed by geoengineers. Success depends above all on minimising the chances of unintended consequences, which in turn depends in large measure on limiting the effects to a bounded geographical area. A disaster following an attempt to manipulate the Earth as a whole would render trivial those resulting from the introduction of the beetle-eating cane toad in Queensland and the rat-eating mongoose in Hawaii. In their review of the lessons of biological control, Damon Matthews and Sarah Turner write that this kind of miscalculation would be unlikely today because of our greater understanding of ecological processes, although they recognise that humans are entirely capable of repeating errors even when knowledge of the consequences is readily available. The assumption that humans learn from their blunders is rarely a safe one.

In trying to get a sense of the likelihood of unintended consequences from system-altering geoengineering schemes, the primary lesson from the study of biological interventions is that the risks increase with both the degree of system complexity and the limits to our understanding of those systems. To date, biological interventions have been confined to ecosystems that are bounded in various ways, so the damage is limited. In the case of system-altering climate engineering schemes the local is the global: every major and minor ecosystem process would be changed by sulphate aerosol injection, marine cloud brightening or ocean fertilisation (just as it is by global warming). The complexity of the Earth system is almost inconceivably deep. Even with leaps in understanding over the next decades, a cascade of unanticipated consequences from intervention seems inevitable. And we return to the disconcerting fact that, despite the enormous advances in climate science over the last two to three decades, each advance opens up new areas of uncertainty. While advances in climate science ought to be teaching us to be more humble, advocates
of schemes aimed at regulating sunlight or interfering in Earthsystem processes seem to draw the opposite conclusion.

We know that ecosystems behave eccentrically, even ones artificially created for their simplicity. They change rapidly over short time-frames, and often develop over long time-frames in ways we barely understand. While Lowell Wood bullishly proclaims: ‘We've engineered every other environment we live in – why not the planet?', a more humble scientist, Ron Prinn, has asked: ‘How can you engineer a system you don't understand?'

The Livermore taint

It is striking to realise how many scientists working on geoengineering have either worked at or collaborated with the Lawrence Livermore National Laboratory, the Cold War nuclear weapons facility outside San Franscisco. The Laboratory was at the centre of the US program to design a range of nuclear warheads and earned a ‘near-mythological status as the dark heart of weapons research'. It was co-founded by Ernest Lawrence, who had received the Nobel Prize for physics, and Edward Teller, soon to become known as a major architect of the Cold War and the most vigorous advocate of the hydrogen bomb.