The word “climate” was conspicuously absent from Joe Hockey’s first budget speech as treasurer. It’s not hard to guess why – the full budget sets out major cuts to climate research, and strong moves against renewable energy programs, such as scrapping the Australian Renewable Energy Authority.
Together, these moves send the strong signal that we are weakening our capacities for both climate knowledge and responses to climate change. As a result, we are increasingly flying blind.
Does this reflect a change in the way in which we, as a society, perceive the risks of climate change? It’s an important question, because although political appetites for action may wax and wane, the laws of nature cannot be repealed.
What the science says
Let’s start with the evidence. The scientific community has just released the landmark Fifth Assessment of the Intergovernmental Panel on Climate Change (IPCC), confirming and extending previous IPCC reports in 2007, 2001, 1996 and 1990.
In snapshot, the findings are that warming and other climate changes have occurred through the 20th century, mainly because of emissions of carbon dioxide and other greenhouse gases by human activities; these changes will continue and accelerate with increasing emissions; and major reductions in emissions are needed over coming decades if we are to significantly reduce dangers from global warming and other impacts.
The observational evidence and models are clear and in agreement on these broad conclusions. This is a scientific consensus in the true sense; not the outcome of a vote, but the outcome of an effort to discern how nature works.
This consensus does not mean that “the science is settled” – far from it. There are still many uncertainties and gaps in our knowledge. They can be summarised like this: if the world succeeds in reducing greenhouse gas emissions strongly, then global warming might range from mild to significant, with the best estimate being warming of about 2C. Conversely, if emissions continue to increase with little or no limitation, warming could range from very bad to catastrophic, with the best estimate being more than 4C by 2100, and even more after that.
We all know that in the face of significant risk, fretting about uncertainty is no substitute for action. Indeed, in making difficult decisions about our future as individuals or as a society, uncertainty about the future is our constant companion. In dealing with climate change, the uncertainty band offered by climate science is nowhere near so cripplingly large as to prevent rational choices.
The choices on offer
Broadly speaking, our options for responding to climate change can be drawn from two boxes: one marked “do something about it”, the other marked “live with whatever happens”. At this highest level, that’s it: no other boxes are available.
In the “do something” box there are three folders of strategies. The first is “mitigation”: reducing emissions of greenhouse gases, primarily carbon dioxide emissions from fossil fuels.
This is the surest way to reduce climate risks. It is technically possible and economically affordable, but politically very difficult, as shown by Australia’s destructive political battles over carbon pricing and direct action.
The second folder is “sequestration”: storing carbon in biological reservoirs such as forests or soils, or capturing it from the exhaust gases of fossil-fuelled power stations and then burying it in geological storage. Both of these options have problems: biologically sequestered carbon is not stored permanently and can return to the atmosphere in droughts, fires or through land clearing, while geological storage faces major technical and economic hurdles.
The third folder is “geoengineering by solar radiation management”. This would involve attempting to reduce greenhouse warming by dimming the sunlight reaching the surface of the earth, perhaps by injecting clouds of tiny particles into the upper atmosphere. Options like this would have massive and still unknown collateral effects that would probably vary hugely around the world – there would be losers as well as winners among people living on different parts of the planet. These options are like the equivalent of highly toxic chemotherapy for a critically ill planet.
Living with it
What of the other box, “live with whatever happens”? This involves adapting to climate change as it occurs, either purposefully or haphazardly. How hard it is to do this will depend on which measures we choose from the “do something” box. If measures to tackle climate change are largely successful and warming is limited to 2C, adaptation will be much easier than it would be in future that is heading to 4C of warming by 2100. In the latter case, “adaptation” might mean massive human misery, and the failure of societies and economies to support their people.
Our climate future will necessarily be a mix of options from these two boxes; nothing else is on the table. Fundamentally, the choice is an ethical one: what risks do we see as the most important, and what are we prepared to pay to manage them?
My own judgement, as a human being rather than a climate scientist, is that the risks of unchecked climate change are very great and that avoiding them should be a very high priority. Moreover, the necessary transformations in energy systems and consumption patterns are both achievable and in many ways desirable. They can be part of a transition to a more sustainable world in ways that include climate stabilisation and also extend beyond it. Cities can be less polluted and better functioning, ecosystems can be less stressed, and the natural life support systems of our finite planet can be better respected.
Knowledge is critical
Whatever value judgements people and their politicians make about climate change, we urgently need knowledge. Gathering knowledge is not easy: it demands diversity, experimentation, and a willingness to fail many times before success is achieved. We need to continue monitoring our changing Earth, including both its natural functioning and the profound ways that we are influencing it.
We need to design strategies for responding to change: doing the painstaking engineering and development of renewable energy systems, working out how to adapt our farms and landscapes, and increasing the energy efficiency and robustness of our towns and cities.
Knowledge is essential because the pace of change is so great that we are creating a world that we do not know, and we need to understand and learn how to live with it even as we shape it. And that, in the larger picture, is why it is not sensible to fly blind.