Newtz Climate Change Blog

The plus 2 degree reality

NASA global temperature data 1880-2009 (Photo credit: Wikipedia)

A 2 Deg C rise in average global temperature (based on pre industrial levels) does’nt sound a lot, but it’s impact on us will be life changing, and for many millions around the globe including many species – a near mass extiinction event !.

2 Deg is the scientific, politcal and internationall accepted temperature rise that will nose dive the globe into irreversible and catastrophic climate change.

The IPCC (the United Nation‘s’ Intergovernmental Panel on Climate Change‘) assess that up to two billion people worldwide will face water shortages and up to 30 per cent of plant and animal species would be put at risk of extinction with violent weather patterns becoming prevailant.

Plus two degrees: the consequences (source IPCC)

Arica: Between 350 and 600 million people will suffer water shortages or increased competition for water. Yields from agriculture could fall by half by 2020 while arid areas will rise by up to 8 per cent. The number of sub-Saharan species at risk of extinction will rise by at least 10 per cent.

Asia: Up to a billion people will suffer water shortages as supplies dwindle with the melting of Himalayan glaciers. Maize and wheat yields will fall by up to 5 per cent in India; rice crops in China will drop by up to 12 per cent. Increased risk of coastal flooding.

Australia/New Zealand: Between 3,000 and 5,000 more heat-related deaths a year. Water supplies will no longer be guaranteed in parts of southern and eastern Australia by 2030. Annual bleaching of the Great Barrier Reef.

Europe: Warmer temperatures will increase wheat yields by up to 25 per cent in the north but water availability will drop in the south by up to a quarter. Heatwaves, forest fires and extreme weather events such as flash floods will be more frequent. New diseases will appear.

Latin America: Up to 77 million people will face water shortages and tropical glaciers will disappear. Tropical forests will become savanna and there will be increased risk of coastal flooding in low-lying areas such as El Salvador and Guyana.

North America: Crop yields will increase by up to 20 per cent due to warmer temperatures but economic damage from extreme weather events such as Hurricane Katrina will continue increasing.

Polar regions: The seasonal thaw of permafrost will increase by 15 per cent and the overall extent of the permafrost will shrink by about 20 per cent. Indigenous communities such as the Inuit face loss of traditional lifestyle.

Small islands: Low-lying islands are particularly vulnerable to rising sea levels with the Maldives already suffering land loss.

So, is the generally accepted reasoning of a 2 Deg rise in global surface temperature the appropriate level at which dangerous climate change occurs consistant with the current scientific data …..

To date, we have already locked in a 0.8 Deg temerature rise !! with only between 1 to 10% chance of limiting the global temperature rise to two degrees centigrade or less.

Climate scientist’s remain silemt on the reality of these facts. The adopted  consensus is that averting a 2 Deg global surface temperature rise is possibly achievable based on climate models using optimistic trends exprapolated form the 1990 baseline. The real situation is very different !.

Recall that Stern reported 0.95% emissions increase per annum, yet the scientific data available at the time showed it was actually 2.4% rise per annum. Climate scientists adopted the optimistic end of the data spectrum Based again on the optimistic end of the data, the accepted current rise is 1 – 2% per annum before we reach a emissions peak. The actual rise based on current ‘actual’ data is between 3 and 6%. This is actually in line with a global temperature rise of between 4 to 6 Deg C by 2050 !.

It is the accumulated emissions that really matter; the day to day build up of carbon. The scientific data is clear that we are on track for a 3.5 to 4 Deg C rise by 2020, and upto 6 Deg by 2050 based on locked-in accumilated emissions.

We need to relook at the consequences outlined by the IPCC above. The actual reality is much more severe and meaning dramatic human  adaptation.

Even if we manage to act decisively now and limit global mean temperature rise to 4 Deg C this will result in 5 to 6 Deg C global mean land temperature. Think of it …..

On the hotest day 8 to 10 Deg C hotter in Central Europe …… 10 to 12 Deg C hotter in New York …… !

Most scientst remain silent on these facts when reporting to their paymasters – those that set policy.

However, Kevin Anderson, one of the lead climate scientists was moved to comment:

“a 4 degrees C future is incompatible with an organized global community, is likely to be beyond ‘adaptation’, is devastating to the majority of ecosystems, and has a high probability of not being stable.”

The following video may be the most important 58 minutes of your life !

Related articles

• Six degrees of devastation (smh.com.au)
• Study: Sea Levels Rising 60% Faster Than Projected, Planet Keeps Warming As Expected (thinkprogress.org)
• Sea level rising faster than IPCC projected (environmentalresearchweb.org)
• Five degrees hotter (theage.com.au)