Climate change - mankind guilty as charged

1 February 2014 – Is there such a thing as climate change, and are humans the cause? The jury might have been out for quite some time, but according to the latest UN report, human influence has been the dominant cause since the mid-20th century and global warming is unequivocal.

According to the latest United Nations report on climate change, atmospheric concentrations of greenhouse gases, already at levels not seen in at least 800,000 years, will persist for many centuries.

“Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system,” according to the report, which finalizes a summary of findings by the UN-backed Intergovernmental Panel on Climate Change (IPCC) issued in September, outlining a litany of threats from the melting of the Greenland and Antarctic ice sheets to rising oceans to extreme weather events such as cyclones and heat waves.

“Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions,” it stresses, using the term “extremely likely” for human causality since the mid-20th century, meaning there is a 95 to 100 per cent probability that humankind, and not naturally occurring phenomena, are to blame, a 5 percent increase from the 90 to 100 per cent “very likely” probability of if the IPCC’s last report in 2007.

Even if emissions of global warming carbon dioxide (CO2) emissions are stopped, most aspects of climate change will persist for many centuries. “This represents a substantial multi-century climate change commitment created by past, present and future emissions of CO2,” the report warns.

It notes that 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, the frequency of heat waves has likely increased in large parts of Europe, Asia and Australia.

For Pacific islands like Palau, Tuvalu and Kiribati, the implications of climate change are clear - and devastating. Already, these governments have begun to plan for a future in which entire populations have to relocate as their islands vanish under the rising sea.

But climate change also threatens ways of life in subtler ways, leaving families around the world to work out for themselves how to cope.


UNRIC's related links:
Library backgrounder on Climate Change: http://unric.org/html/english/library/backgrounders/climatechange_eng.pdf
Green growth & Gender Equality: http://unric.org/en/latest-un-buzz/28945-no-green-growth-without-gernder-equality