Climate change so far

Global climate indicators

• Global average air temperature has risen by nearly 0.8°C since the late 19th century, rising by about 0.2°C per decade over the past 25 years. It is very likely that human emissions of greenhouse gas emissions caused most of the warming since the mid 20th century.
  
  
• Global sea-level rise has accelerated between mid-19th and mid-20th century, and is now rising at about 3 mm per year. It is likely that emissions of greenhouse gases from human activities have contributed between a quarter and a half of the rise in global sea-level in the last half of the 20th century, the rest being due to natural causes.
  
  
• Arctic sea ice extent has decreased by an average of 2.7 per cent per decade since satellite observations began in 1978.
  
  
• Mountain glaciers and snow cover in both hemispheres show a general decline in extent that is consistent with global warming.
  
  
• IPCC’s Fourth Assessment Synthesis Report

UK climate indicators

Central England Temperature (CET, a data record that extends back to 1659) has risen by about a degree since the 1970s. The rise in CET is considerably faster than that of the global average temperature.

• Annual average precipitation has not changed since records began in the late 18th century. Seasonal precipitation has decreased in summer and increased in winter. Over the last 50 years, winter precipitation appears to have fallen in more intense bursts.
  
  
• Sea level around the UK rose by about 1mm/yr in the 20th century, corrected for land movement. The rate for the 1990s and 2000s has been higher than this, at 3−4 mm per year.
  
  
• Sea surface temperatures around the UK coast have risen over the past three decades by about 0.7°C.
  
  
• 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.
  
  
• For more information see the Climate of the UK and Recent Trends report on the UK Climate Projections website

Next step:

• Find out how the UK climate is likely to change