ENVIRONMENT

IPCC report affirms reality of 2⁰Celsius rise over industrial-age levels

Ø  The UN Intergovernmental Panel on Climate Change concluded on Friday(27-09-2013)that it is now more certain than ever before that human-caused climate change is real, and greenhouse gas emissions are causing changes to the planet that could possibly trigger dangerous consequences by the turn of the century.

Ø These conclusions came as part of the Summary for Policymakers (SPM) on the physical science of climate change.

Ø  The report was formally adopted in Stockholm on Friday27-09-2013). The last such report was brought out in 2007.

Ø The panel concluded that the “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. 

Ø The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.”

Ø  “Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850.”

Ø Greatest alteration to climate is caused by the cumulative carbon dioxide emissions, as compared to other short-lived, climate-forcing gases.

Ø In the relative short-run, global mean surface temperatures are likely to increase in the range of 0.3-0.7 degree Celsius over the 1986-2005 average. Over the long run, between 2081 and 2100, the temperatures are likely to rise anywhere between 0.3-4.8 degree Celsius depending upon how much more emissions are released.

Ø  Unless strong emission reduction measures are taken in coming years the likelihood of temperature increase as compared to industrial-age levels remaining below 2 degree Celsius are less than likely. The 2 degree Celsius increase is taken as a tipping point beyond which scientists believe dangerous levels of climate change would be unleashed.

Ø  Limiting the warming to less than 2 degree Celsius with a 66% confidence level requires that cumulative carbon dioxide emissions are restricted to 840 giga tonnes of carbon (GtC). The cumulative carbon dioxide emissions had touched 545 GtC by 2011.

Ø  Indicators of climate change, such as seal level rise, arctic ice cover are showing a monotonous trend of things getting worse with rise in emissions.