What is the current climate situation?

The International Panel for Climate Change (IPCC) released the first of their summary reports on 27 September 2013. A summary of findings and impacts on the global environment include:

  • Temperature The global average air temperature has risen by around 0.85°C since the beginning of the 20th century, and continues to rise
  • Decadal Average Temperature The period 2001–2010 was the hottest decade on record
  • Ocean Heat Content The ocean absorbs over 90% of the extra heat and has warmed since the 1970s with much of the heat stored in the upper 700 metres. Recent observations show warming in the deeper areas of the ocean below 3000 metres in the North Atlantic and Southern Ocean
  • Arctic Sea Ice The annual average sea ice extent over the Arctic Ocean has decreased at a rate of 3.5 to 4.1% per decade over the period 1979– 2012. Overall since 1950 the sea ice extent has dropped to nearly half.
  • Ocean Acidity the pH of seawater has decreased by 0.1 since the beginning of the industrial era, corresponding to an increase in acidity of 26%
  • Sea level has risen by 19 cm over the 1900– 2010 period and at an increased rate over the period since 1993, with a sea level rise trend about 3.1 mm/year in last decade
  • Atmospheric CO2 (carbon dioxide) trend has been increasing at about 2.1 ppm/year in the last decade (up from 1.7 ppm in the previous decade).

Source: http://www.ipcc.ch/news_and_events/docs/ar5/ar5_wg1_headlines.pdf