Recent climate trends

Average global temperature and sea level have risen since the late 19th century, and at an increased rate over the past few decades.

  • Warming of the global climate system is unequivocal, with global average temperatures having risen by nearly 0.8 ºC since the late 19th century, and rising at about 0.2 ºC/decade over the past 25 years.
  • It is very likely that man-made greenhouse gas emissions caused most of the observed temperature rise since the mid 20th century (IPCC Fourth Assessment Report, 2007).
  • Global sea-level rise has accelerated between mid-19th century and mid-20th century, and is now about 3 mm per year. Human activities have likely contributed between a quarter and a half of the rise in the last half of the 20th century (IPCC Fourth Assessment Report, 2007).

Observed trends for the UK

Average UK temperature has risen since the mid 20th century, as have average sea level and sea surface temperature around the UK coast. Over the same time period, trends in precipitation are harder to identify.

  • Central England Temperature has risen by about a degree Celsius since the 1970s, with 2006 being the warmest on record. All regions of the UK have experienced an increase in average temperatures between 1961 and 2006 annually, and for all seasons. Increases in annual average temperature are typically between 1.0 and 1.7 °C, tending to be largest in the south and east of England and smallest in Scotland.
  • All regions of the UK have experienced an increase over the past 45 years in the contribution to winter rainfall from heavy precipitation events; in summer all regions except north east England and north Scotland show decreases.
  • Severe windstorms around the UK have become more frequent in the past few decades, though not above that seen in the 1920s.
  • There has been considerable variability in the North Atlantic Oscillation, but with no significant trend over the past few decades.
  • Sea-surface temperatures around the UK coast have risen over the past three decades by about 0.7 ºC.
  • Sea level around the UK rose by about 1 mm/yr in the 20th century, corrected for land movement. The rate for the 1990s and 2000s has been higher than this.
  • The annual number of days with air frost has reduced in all regions of the UK between 1961 and 2006. There are now typically between 20 and 30 fewer days of air frost per year, compared to the 1960s, with the largest reductions in northern England and Scotland.
  • There has been a decrease in the average number of Heating Degree Days (HDD), and an increase in the average number of Cooling Degree Days (CDD) in all administrative regions of the UK as a whole, between 1961 and 2006.
  • There has been a slight increase in average annual precipitation in all regions of the UK between 1961 and 2006, however this trend is only statistically significant above background natural variation in Scotland where an increase of around 20% has been observed. Likewise for an increase in average winter is only statistically significant in northern England and Scotland where increases of 30– 65% have been experienced.
  • Average annual and seasonal relative humidity has decreased in all regions of the UK, except Northern Ireland, between 1961 and 2006, by up to 5%.