Both David Cameron and Ed Miliband agree that extreme weather provides evidence of climate change. But there is a difference in tone.
Last month the Prime Minister said:
We are seeing more abnormal weather events. Colleagues across the House can argue about whether that is linked to climate change or not; I very much suspect that it is. The point is that, whatever one’s view, it makes sense to invest in flood defences and mitigation and to get information out better, and we should do all of those things.
This morning, interviewed for The Observer, Mr Miliband said:
“In 2012 we had the second wettest winter on record and this winter is a one in 250-year event. If you keep throwing the dice and you keep getting sixes then the dice are loaded. Something is going on.”
Mr Miliband feels Mr Cameron’s inclusive tone is “pretty extraordinary.”
In order to flag up a difference Mr Miliband stresses his own sense of absolute certainty.
But do we keep getting sixes? 2010 was unusually dry. 2003 was even more dry. 2004 was unusually wet. 2005 and 2001 were exceptionally average. As Paul Simon and Art Garfunkel would put it, Mr Miliband seems to be a man who “hears what he wants to hear and disregards the rest.”
In one respect it is the climate change zealots who load the dice. A mild winter? Evidence of global warming. A cold winter? Extreme weather giving further proof of climate change. What would it take to disprove the theory?
Surely any scientist would wince at Mr Miliband’s lack of sophistication in offering a couple of examples from one country to establish certainty? Even Sir Brian Hoskins, among the most convinced of the evidence of climate change, said that there is “no quick or simple answer” as to whether or not there was a link to extreme weather.
An analysis by Dr Madhav L. Khandekar and Professor Brian R. Pratt for the Global Warming Policy Foundation said:
During the period 1945-1977 when the mean temperature of the Earth declined by about 0.25°C, there were a number of notable (and tragic) extreme weather events. Most climate scientists attributed these extreme weather events to natural climate variability.
It adds “that hurricanes and tropical storms do not show increasing trends in frequency or in intensity” and:
When closely examined there appears to be no increase in extreme weather events in recent years compared to the period 1945-77, when the Earth’s mean temperature was declining. The global warming/extreme weather link is more a perception than reality.
The purported warming/extreme weather link has been fostered by increased and uncritical media attention to recent extreme weather events. The latest IPCC documents appear to de-emphasize the warming/extreme weather link by suggesting ‘low confidence’ in linking some of the events to recent warming of the climate.
Cold weather extremes have definitely increased in recent years; for example, the severe winters in Europe (2012/13, 2011/12, 2009/10) and North America (2012/13, 2007/08). There have also been colder winters in parts of Asia (2012/13, 2002/03) and South America (2007, 2010 and 2013).
The Earth’s climate may witness cold as well as warm weather extremes in future (between now and 2025). The best way to cope with present and future extreme weather events is to develop improved seasonal (long-range) climate forecasting capability, so as to minimize any adverse impacts of such events. A recent report (Goklany 2011) documents how human fatalities from extreme weather have declined significantly during the global warming era of the twentieth century.
The report points out that improved food productivity and increased wealth in developing nations has enabled these countries to cope with such extreme weather events and to reduce damage to property and the loss of human life.
Regarding flooding it says:
“A recent (February 2011) issue of the journal Nature Climate Change had an editorial on the topic ‘Human influence on rainfall’, citing several papers that suggested a strong human influence (via increased concentrations of atmospheric carbon dioxide) on recent rainfall extremes in the UK.
“A careful analysis of these papers, however, reveals that there is no consistent trend in extreme precipitation in any region of the UK. Two recent papers on extreme precipitation - one for the UK (Rodda et al. 2010) and the other for the Zhujiang river basin in South
China (Gemmer et al. 2011) – use daily precipitation data for over 100 rain-gauge stations in the UK and China over the period 1960-2006. Both papers conclude that extreme precipitation trends are not consistent everywhere and that natural variability can explain most of the observed trends. The study by Rodda et al. concludes that ‘Ascribing changes in extreme rainfall in the UK to human-induced climate change remains problematical’.
The tornado death toll each year in the United States does not suggest a clear pattern.
In 2006 the environmentalist George Monbiot wrote a book called “Heat: How to stop the planet burning”. This stated that “our rivers are starting to run dry.” He forecast global warming, which in turn would lead to more “drought events.” It will be silly to take so short term and parochial a view as to suggest that Mr Monbiot’s prediction is disproved by the high rain fall in the UK over the past two months. It is just as silly for Mr Miliband to suggest the recent incidents of flooding prove the existence of global warming.
But also trying to look for divisions isn’t always productive. For instance, whether or not pollution from machines is causing global warming, obviously cleaner engines would be welcome to reduce air pollution – which is a major cause of death.
Similarly the message that we should try to improve flood defences, whether or not we believe that floods are likely to become more frequent, seems reasonable. The focus should be on the most practical, cost effective, ways of doing so.