Irrationalism on climate change action

Time series of maximum summer melt extent over Greenland from 1979 to 2002 (left) and the melt extent in 1992 and 2002 (right)

Time series of maximum summer melt extent over Greenland from 1979 to 2002 (left) and the melt extent in 1992 and 2002 (right)

Originally published in the Independent Weekly newspaper (Adelaide), March 2008

Last year, the socio-political terrain surrounding climate change shifted dramatically. The clarion call for urgent action to slow global warming was sounded loud and clear by the scientific community. The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report stated bluntly that without a rapid global response, we are headed, within decades, for an environmentally hostile future. In 2007, the extent of Arctic sea ice plummeted 22% below the previous minimum. After a change of federal government, Australia finally ratified the Kyoto protocol, and at the Bali conference, the European Union proposed emission cuts of 25 to 40% by 2020.

Yet, most of those who are deeply concerned about climate change and other forms of environmental degradation, be they scientists, business people, representatives of climate action groups, or engaged members of the general public, continue to feel that very little meaningful action is actually being undertaken. Why is that?

No lack of evidence

There are numerous persuasive reasons – detailed in the IPCC report and more recent literature – to consider the climate crisis to be the defining issue of our time, one that demands urgent action.

For instance, the science tells us that if deep and ongoing cuts in greenhouse gas emissions cannot be achieved globally within the next 20 years, then we, and our descendents for generations to come, will inhabit a radically transformed planet.

This includes a globally averaged temperature rise of 3 to 6°C and an eventual – and perhaps rapid – collapse of the Greenland and West Antarctic ice sheets with an attendant 14 metres of sea level rise. There also looms the risk of more frequent and severe droughts and spreading deserts, more intense flooding, a huge loss of biodiversity, and the possibility of a permanent El Niño.

Frequent failures of the tropical monsoons and complete loss of most mountain glaciers will deplete supplies of water required to feed the billions of people in Asia, Africa and South America. Sea level rise will result in many millions of climate refugees being displaced from coastal and low-lying regions and port cities, and a major disruption to harbours and sea trade.

Indeed, it is no exaggeration to state that the current and projected future impacts of climate change threaten dire consequences for the functioning of our modern civilization and most of the natural systems we depend upon.

Our actions are also rapidly degrading the Earth’s natural capital. Beyond climate change, there is ongoing deforestation, over-exploitation of fisheries, massive diversion of freshwater surface flows and draw-down of groundwater aquifers, and contamination and exhaustion of soils through unsustainable agricultural practices.

Many of these issues will be all too familiar to South Australians: extinction of more than 20 unique species of arid-zone mammals, the spectre of rising dry land salinity, and severe water shortages leading to urban water restrictions, vastly reduced irrigation quotas, and the collapse of the Coorong wetlands.

These critical drivers of global change were reviewed in detail in the little-cited, yet extremely comprehensive, 2005 Millennium Ecosystem Assessment – the ecological equivalent of the IPCC report. It showed that, without its biological life support system intact, humankind’s well being – be it the health of individuals, societies, or global economies – will be severely and perhaps irreparably compromised during the 21st century.

It is abundantly clear that the threats of climate change and other forms of environmental degradation represent a clear and present danger to our way of life. So I return to my earlier question – why is so little being done to prevent this damage?

In truth this is a devilishly complex issue. Nevertheless, I think the answer comes back to a few key points about human behaviour.

Barriers to decisive action

First, people are notoriously bad at judging risk. For instance, we consider potential hazards much more seriously if we have personally experienced them, or seen them occur in the media, or even if we know them to have happened historically. None of these apply to the present global crisis of climate change.

At best, for a precedent, we must look back to natural catastrophes that occurred thousands or millions of years ago, or to the collapse of ancient civilizations due to regional climate shifts. So the climate forecasts for this century and beyond must appear, to many, to be a distant and intangible problem. Similarly, the associated risks and impacts of global warming, falling far outside of the realm of our everyday experience, might seem to be only a vague and uncertain prediction.

Second, our default method of dealing with seemingly intractable problems has been to compromise, to take the middle ground, or to soft-pedal on what is required for a full solution. This works, albeit imperfectly, for small scale problems – no one gets quite what they wanted, but no one loses out entirely either.

However, given the wholesale planetary transformation that is threatened by climate change, ‘concession goals’– such as a long-term target of a 60% reduction in emissions by 2050, or voluntary commitments to improve energy efficiency – just won’t cut it. These compromise decisions risk allowing the climate system to pass irreversible tipping points, whereby a 2°C target becomes 5°C of warming due to cascading effects that are out of our control, such as rapid ice sheet loss and carbon dioxide release from the oceans.

Third, the value of implementing a policy option is traditionally assessed using a marginal cost-benefit analysis. Using this method, incremental adjustments in policy are assumed to cause progressive shifts in the intended outcome. As a hypothetical example, for every one dollar increase in a carbon tax, domestic emissions might be expected to decrease by 1%, and economic growth to decline by 0.01%. Given sufficient adjustment to the carbon price, this approach could lead to a significant, albeit gradual, decrease in emissions. It would also impose accumulated costs to the economy, and benefits to the environment. The magnitude of those costs and benefits would be dependent on the rate and extent of greenhouse gas reductions.

It is often claimed, under these marginal value models, that it makes more economic sense to continue to emit substantial greenhouse gases now, and only mitigate our emissions more stringently when new technologies make it less expensive to do so, or once the impacts of climate change become more widespread and damaging.

Facing our responsibility

I argue that this ‘economically rationalist’ approach to dealing with climate change is unacceptably irresponsible, because it ignores a substantial danger – that ongoing global warming will cause the physical and biological systems of Earth to cross thresholds which occur suddenly and are irreversible. We cannot be certain about the precise global temperature change needed to trigger these climate-driven flips, but the study of past climate change tells us, very clearly, that such state transitions are inevitable. Once they occur, there will be no winding back the clock.

In sum, if rational environmental concerns continue to be neglected in the near-term, in favour of the myopic and unsustainable pursuit of ‘growth at all costs’ based on a Victorian-era model of fossil-fuel industrialisation, then our future world will be far more hostile to civilization and biologically poorer. We, as global citizens, simply cannot afford to wait, or allow the delay to continue.



  1. Our actions are also rapidly degrading the Earth’s natural capital. Beyond climate change, there is ongoing deforestation, over-exploitation of fisheries, massive diversion of freshwater surface flows and draw-down of groundwater aquifers, and contamination and exhaustion of soils through unsustainable agricultural practices.

    To which we might have to add another, and potentially very serious, problem to the list:


  2. That’s certainly an interesting proposition; however, I believe the catastrophic loss of habitat (i.e., generally forests) will engender a whole series of cascading effects that will reduce the quality of human life well before oxygen depletion becomes an issue. Essential ecosystem services such as pollination (for crops, among other plant life), water purification, water availability, flood prevention, waste processing, carbon sequestration, resilience against invasive species (e.g., pine beetles), etc. are being severely degraded (see relevant posts in here and here). Let’s hope that oxygen doesn’t become limiting in addition to water and food. There’s not much good news, is there?

    CJA Bradshaw


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