The Science is Unequivocal on Climate Change

The Intergovernmental Panel on Climate Change’s Climate Change 2013, also known as the IPCC’s Fifth Assessment Report (AR5) was released September 27th at their meeting in Stockholm, Sweden.  The report consists of thousands of pages of detail that draws on the work of more than 800 scientists and hundreds of scientific papers.  The findings are that there’s been a 40% rise in carbon dioxide and other greenhouse gases since pre-industrial times, primarily due to burning fossil fuels.  It states:

Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia…each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850…Changes in many extreme weather and climate events have been observed since about 1950…It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.

Scientists are 95% certain that burning fossil fuels and deforestation are responsible for the warming of the planet and its oceans, leading to the melting of glaciers, the retreat of artic sea ice, the rise in sea levels, and the increased occurrence of extreme weather events including heat waves, storm surges and changes to rainfall.

The panel warns that continued emissions of greenhouse gases will cause further warming and changes in all aspects of the climate system.  The message is that a reduction in emissions is still possible with sustained and substantial actions now.  That includes not burning all the remaining fossil fuels, and a serious commitment to energy efficiency and renewable energy, to forests and agricultural lands, and to advanced information technology.