The UK Met Office has just released its latest 30-year climate average. Readings show the UK’s annual mean temperature calculated over a thirty year time period has risen 0.52 degrees Celsius over the past two decades. The data handily illustrates scientists’ explanation that long-term warming is continuing despite temperature fluctuations over shorter timescales.
The Met Office says the biggest departure from previous years is in the mean UK annual temperature. At 8.84 degrees Celsius, the annual mean temperature between 1981-2010 is 0.25 degrees Celsius higher than during the 1971-2000 period, and 0.52 degrees Celsius warmer than it was between 1961 and 1990.
Mike Kendon of the Met Office National Climate Information Centre says in a statement:
“At a regional level and for individual seasons we expect variability on decadal timescales, from natural cycles, to play a role. Nevertheless, the increases in UK annual mean temperature are consistent with the trend in warming observed globally over land.”
You can see the new statistics in maps of the UK and tables for weather stations, regions and countries on the Met Office website’s climate pages. The maps give an idea of how the warming is distributed over the UK. We have even made an animated GIF to illustrate the warming better, (click the image) but you can find non-moving maps and other interesting things like rainfall patterns on the climate pages.
Click to animate:
The maps (especially when skilfully animated) illustrate scientists’ argument in the the face of the popular skeptic claim that global warming has stopped over the past 10-15 years. As we explain in a previous blog, over 10-to-15 year timescales, natural variation can mask longer-term rising temperature trends.
While the Met Office’s year-to-year temperature maps show all sorts of variations in the UK’s temperature, its 30-year mean annual temperature data shows a clear warming trend in line with global surface temperature rise.
The Met Office isn’t the only scientific body that provides climate ‘normals’. The US National Oceanic and Atmospheric Administration’s National Climatic Data Center released its 1981-2010 average climate statistics last year. It says the US is now around 0.28 degrees Celsius (0.5 degrees Fahrenheit) warmer than it was in 1971-2000, so not far off the UK equivalent rise in temperature.
The Met Office says that the UK now gets 1.154 metres of rain on average per year. The past 30 years have been wetter – with two per cent more rainfall than in 1971-2000 and five per cent wetter than 1961-1990. The Met Office stresses that these figures mask regional and seasonal variations, but says the increase in rainfall is still consistent with the year-on-year warming trend.
Peter Stott, Head of Climate Monitoring and Attribution at the Met Office says more rainfall may be partly due to a warmer atmosphere able to hold more moisture, possibly leading to heavier rainfall. So, some uncertainty there. In the Met Office’s press release, he says:
“Globally we have seen an increase in heavy rainfall, but more research needs to be done to be clear on how a warming atmosphere and variations in weather patterns may be affecting averages in the UK’s regional climate.”
The new UK 30-year average will provide the benchmark for the Met Office’s monthly, seasonal and annual climate summaries, which provide shorter-term reports on the UK’s climate. The Met Office’s summary for July, for example, shows the UK mean temperature was one degree below the 1981-2010 average. It was the coolest July since 2000 – so yes, it was an unusually rubbish summer, even if on average we’re getting more sunny days.
Yes, surprisingly, the UK is a sunnier place than it was – not that it will make anyone feel any better about having to wade through prodigious amounts of mud all summer. With an average of nearly 58 days of sunshine a year in the 1981-2010 period, the nation got 18 hours of sunshine more than in 1971-2000, and an extra 35 hours if you look back to 1961-1990. Which just goes to show how counterintuitive long-term climate shifts can seem when the weather looks so very different.
Update 4pm: We had mixed up the amount of temperature rise in the first paragraph, and not made it clear that we were talking about thirty year time periods. This should now be accurate and clearer. Thanks to Paul Matthews for the spot.