There’s been a lot of talk about average global temperatures for 2010 – the Met Office and the University of East Anglia show it to be the ‘second warmest on record, with a mean of 14.5C – 0.5 degrees warmer than the average from 1961-1990.
The NOAA and NASA ‘s Goddard Institute agree. With the increasing occurrence of long, harsh winters in the UK, many may be putting the idea of ‘global warming’ far from their minds. However it is exactly this – extreme localised weather – that is a clear indicator of ‘global warming’.
It is crucial to differentiate between ‘weather’ and ‘climate’. These words are often bandied about with little thought for their actual meaning – however if one is used in place of the other, the meaning is greatly changed. Weather relates to the atmospheric conditions at any one time in any one location – e.g. rain across London, or snow across the North East of England. Climate is the average weather over a long period of time – e.g. the UK climate is generally warm, dry summers and cold, wet winters. Therefore, extreme localised weather events, such as the dramatic snowfall across the UK at the end of last year, whilst contributing to the climate average, will not affect or represent the overall warming trend.
Climate scientists believe that the increasing global temperature will result in extreme local weather events of all kinds, both hot and cold. Examples of this were splashed across the news in 2010 with increasing frequency, showing that the UK was far from the only country to experience extreme weather last year – a heat wave in Russia, flooding in Sri Lanka and China, to name but a few. Each of these events in isolation would not be indicative of ‘global warming’, however the fact that they all occured in the same year, at a much higher frequency than has been previously recorded would suggest that it is related to the rise in global temperatures.
For humans, it is hard to think on the large time-scales required of climate science, but if our children, or more likely are children’s children are going to have any semblance of the lives we currently lead, we’re going to have to try a lot harder.
However, it is also important to point out that global climate and weather are complex systems, with numerous drivers. Although there can be little doubt that the planet is warming, many factors affect local and regional weather, including the El Nino/La Nina phenomena (2010 was a La Nina year) among others.
Whilst all this talk of increasingly variable/extreme weather may be rather daunting, the accuracy of weather and climate predictions is being improved upon all the time (according to the Met Office), meaning predictions can be made further into the future, allowing for governments to plan ahead to reduce loss of life – as demonstrated so well by the small (but not insignificant – any loss of life is regrettable) number of deaths caused by the vast flooding in Brisbane just a few weeks ago.
To be able to deal with the possibility of an increasing incidence of such events, a wider understanding of this admittedly complex area is needed. It is my hope that this would also prevent the type of misguided statements such as those still being bandied about by the UK tabloids, which harks back to my earlier point about weather and climate, and the fundamental need to understand the difference between the two.
No doubt the same journalists will have done a u-turn when summer comes again and we are experiencing extremes of heat, water shortages etc – again showing their lack of understand of localised weather, or even the changing of the seasons.
It is only through clearer communication that misconceptions and wilful misunderstandings like these will be overcome.