Human influence on climate clear, IPCC report says

27 Sep 2013

Human influence on the climate system is clear. This is evident in most regions of the globe, a new assessment by the Intergovernmental Panel on Climate Change (IPCC) concludes.

Photo: UNDP in Sudan

Ankara - It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.

The evidence for this has grown, thanks to more and better observations, an improved understanding of the climate system response and improved climate models.

Warming in the climate system is unequivocal and since 1950 many changes have been observed throughout the climate system that 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, reports the Summary for Policymakers of the IPCC Working Group I assessment report, Climate Change 2013: the Physical Science Basis, approved on Friday by member governments of the IPCC in Stockholm, Sweden.

Projections of climate change are based on a new set of four scenarios of future greenhouse gas concentrations and aerosols, spanning a wide range of possible futures.

The Working Group I report assessed global and regional-scale climate change for the early, mid-, and later 21st century.

“As the ocean warms, and glaciers and ice sheets reduce, global mean sea level will continue to rise, but at a faster rate than we have experienced over the past 40 years,” said Co-Chair Qin Dahe.

The Summary for Policymakers of the Working Group I contribution to the IPCC Fifth Assessment Report is available at www.climatechange2013.org or www.ipcc.ch .