The radical view – the threat of runaway climate change
Some believe we are now threatened with “runaway climate change” because global warming is not simply a linear process in which a given level of emissions leads to a given concentration of GHGs and temperature rise. The climate is a complex system that has many feedback processes whereby one impact leads to another. For example,
one major feedback factor is that as ice melts, it loses its reflective quality, or ‘albedo’, and instead absorbs incoming heat – a process called the ‘albedo-flip’. So the action of heat on ice is not a linear process in which a given rise in temperature melts a given volume of ice.
In fact, as the warming continues, the ice melts faster and the rise in sea levels accelerates. While acknowledging the risk of feedbacks, the IPCC projects a modest range of sea level rises during the 21st century – most under half a metre. But James Hansen, Director of NASA’s Goddard Space Science Laboratories, and a seasoned climate expert, says this sends the wrong signals to policy-makers, He warns that ‘business-as-usual’ emissions would trigger the albedo-flip effect during this century and says the Earth faces “imminent peril”. Hansen believes it is necessary to take carbon out of the atmosphere and reduce the concentration of CO2 to 350ppm in order to preserve the Arctic’s sea ice and prevent catastrophic flooding.[1] He has also asserted that that the dangerous level of global warming is closer to 1°C than 2°C , largely of evidence from the Earth’s history that a greater level of warming is likely to cause large sea level change over centuries.
Peter Wadhams, Professor of Ocean Physics at Cambridge University, has shown how Arctic sea-ice as measured each September – from over 8 million sq km in 1950 to close to 4 million now - is not only shrinking faster that the mean projection of earlier models, but faster than the lower limit of the standard deviation of the models – the ‘plus or minus’ that indicates the range of expected outcomes. This presents a major challenge to the consensus view.
Many who study feedbacks believe that the focus on CO2 levels and temperature rises is too narrow and that climate change demands a more holistic ‘systems dynamics’ approach which embraces all elements of the world’s ecology.
David Wasdell, International Co-ordinator of the UK-based Meridian programme, has warned of a series of feedback effects, ranging from the albedo-flip and increasing methane emissions to increased volumes of water vapour due to increasing evaporation. He and others believe that the critical factor is the level of ‘radiative forcing’ – or heat – in the climate system – heat being to global warming what a gas burner is to a saucepan. Wasdell says that the key target is to push radiative forcing from its current level of around two watts per square metre down to zero. In his analysis, allowing the global temperature to rise by 2°C would be disastrous because it would entail approximately doubling the power of the heat engine and pushing the climate across a range of dangerous ‘tipping points’ including a major sea level rise. Wasdell therefore advocates moving immediately to a low-carbon, and then a no-carbon economy and then into a phase of carbon removal, using such measures as production of biochar, a form of charcoal that absorbs carbon as well as providing energy.
The godfather of this radical school of thought is James Lovelock, originator of the Gaia hypothesis, who has likened his task as a scientist to that of young police officer breaking news of a murder to the victim’s family. He predicts that the temperature will rise by 8 degrees this century, that billions will die and the few remaining ‘breeding pairs’ of humans will migrate to the Arctic.
Some have even contemplated the extinction of the human species, after what would have been a much shorter stay on Earth than the dinosaurs. They foresee our brief period on the planet being studied by some future life forms as the ‘Anthropocene Era’.
The message is that if we proceed on the basis of only what we can prove, rather than the graver unproven but genuine risks, we will fail to act strongly or swiftly enough. Scientific certainties simply tell us we face a crisis, but the uncertainties pose the risk of complete catastrophe.
Wasdell says: “It feels like we still have a comfort zone in which we can fine-tune our response, get everybody on board, check that our body-politic is ship-shape and to coin a phrase is ‘fit for purpose’. Sadly a mounting body of evidence suggests otherwise. We are now in the early stages of runaway climate change.”