Warming Up – But Can we Stand the Heat?

The Met Office prediction of a hot summer ahead has been one of the few rays of sunshine in a gloomy news period, dominated by depressing financial news and politicians and their grubby attempts to claim ‘expenses’.

In a surprisingly forthright forecast, the Chief Meteorologist Ewen McCullum of the Met Office proclaimed that 30 degree temperatures were on their way. The forecast was for a drier and warmer than average summer across the country.

                   Looking forward to those 30 degree temperatures

The summers of 2007 and 2008 were disappointingly wet and cloudy, exceptional even be the dismal standards of the typical British summer. So Mr McCallum probably though he was on safe ground, promising an improvement on the previous two summers.

Unfortunately long-range forecasting is still very much in its infancy and results from previous summer and winter predictions do not stand up to detailed scrutiny. Neither the wet summer of 2008 nor the rather cold winter just past were forecast by these techniques. Whether the techniques used have really improved to such an extent, and in such a short space of time, that the results can be announced with such a fanfare remains to be seen.

To be fair, even the Met Office is keen to point out that that these predictions “…are not forecasts which can be used to plan a summer holiday or inform an outdoor event”. Yet that is exactly what people will want to use them for. Whether it is the Ashes test series or the Glastonbury music festival, there will be a tendency to presume that the weather will be fine.

Unfortunately that is not the case. A closer look at the predicted ‘barbecue summer’ reveals a surprising lack of detail, merely a promise of ‘warmer than average’ temperatures and ‘near or below’ rainfall. It is still perfectly possible to get some really wet and dull weather through the summer without breaking the above parameters.

            One way of keeping cool in a warmer world

Perhaps in the future the city dwellers amongst us will be less excited about ‘sizzling summer’ predictions. Research by the Met Office has shown huge spatial differences in likely temperature rises as the world continues to warm over the coming century.

The ‘heat island’ effect has been well documented. Urban areas tend to be much warmer than the surrounding rural areas as heat sources – shops, factories, vehicles etc – keep urban temperatures considerably higher than rural ones.

On a summer’s day, city centre temperatures may be 3 or 4 degrees higher than surrounding areas. At night, as heat stored in the fabric of roads and buildings is released, urban temperatures can be 5 or 6 degrees higher.

These differences are expected to increase even further as urban populations struggle to combat rising temperatures. By the end of the century it is predicted that this difference could be as much as 10 degrees making city dwelling – which continues to grow around the globe – increasingly difficult.

Perhaps in 100 years time forecasts such as the one recently issued by the Met office will not be greeted with such enthusiasm.