Madam, – I feel compelled to respond to David Whitehead (December 7th).
My intent is not to dissuade Mr Whitehead of his own views so much as to set the record straight on the actual science of climate change. Mr Whitehead writes that a large number of scientists disagree with the findings of the UN body on climate science known as the Intergovernmental Panel on Climate Change (IPCC). While some of those who ignore scientific evidence may call themselves scientists, anyone who clearly understands the scientific process can be in no doubt that the weight of evidence overwhelmingly points to the fact that the climate is warming, and that the use of fossil fuels is the primary cause.
That a scientific consensus exists on the cause of global warming is testimony to this fact. Science does not ordinarily work by consensus; rather, it progresses by testing existing hypotheses and challenging convention. Consensus only exists among the international scientific community in cases where the evidence is indisputable. Take as an example the theory of continental drift put forwarded by Alfred Wegener and others to explain the formation of the Earth’s continents. This was rejected by the scientific community for 50 years until plate tectonics were revealed as a plausible mechanism.
On several points, Mr Whitehead fundamentally misreads the science, or overlooks the most recent scientific evidence. He selectively chooses to discuss the warming that would ensue for four of the IPCC’s “what if” scenarios used to project future possible climates. Tellingly, those he dismisses are actually the scenarios based on continued use of fossil fuel energy, which result in a projected warming of as much as 6.4 degrees Celsius by 2100. Currently, anything above 2 degrees Celsius is recognised in EU policy as constituting a dangerous level of interference with the climate. With warming of 2 degrees Celsius above pre-industrial values, we will see a maelstrom of impacts – from rising seas to worsening droughts – some of which society will be unable to adapt to.
Mr Whitehead makes the common mistake of assuming that because there is large regional variation in surface temperature on Earth, then a warming of a few degrees will not matter. But he misses the point that an average increase of 2 degrees Celsius or 3 degrees Celsius would be catastrophic for areas that are already suffering from water shortages. If this happens, summer heatwaves such as that in Europe in 2003, which killed 30,000 people, could become annual events.
On the issue of sea level rise, the IPCC acknowledges in its 2007 report that it does not take into account the effect of glacial dynamics – in other words, the sea level rise that would ensue from the calving of icebergs into the ocean, a phenomenon increasingly observed around the edges of Greenland and Antarctica in recent years. Since the 2007 IPCC report, scientists have re-calculated projected sea level rise. Several independent lines of evidence published this year suggest that sea level is likely to rise 1m by 2100.
Of course, while this might not sound like much in Ireland, it would have devastating impacts for those inhabitants of large deltaic nations such as Bangladesh, small island nations such as the Maldives (which rises only 1.5m above sea level), and for countries with large low-lying areas that are highly developed such as the US. The worst impact of sea-level rise will not be loss of land due to encroachment of the ocean, but increased vulnerability to storm surges and destruction of cropland.
It is true that there are many potential environmental hazards waiting to happen at some time in the future. But this is different: precisely because we are responsible for climate change we have the ability to do something about it. The longer we delay acting on climate change, the more expensive the problem will become, as targets for reducing emissions become harder to achieve and impacts escalate.
Mr Whitehead’s misunderstanding of the science of climate change would be amusing were it not for the fact that preventing an environmental catastrophe, and assuring a decent quality of life of many of the world’s most vulnerable people, rests on public understanding of global warming and on the political willpower to take action. – Yours, etc,