http://www.independent.co.uk/environment/climate-change/life-on-earth-under-threat-from-co2-levels-say-scientists-8612900.html

Life on Earth under threat from CO2 levels, say scientists 


Steve Connor  
Sunday 12 May 2013 

Email 

Related articles
  a.. 'Recklessly slow' climate talks as greenhouse gases hit new high 

  b.. Michael McCarthy: These leaks do nothing to undermine the case for 
man-made global warming 

  c.. Record rise in greenhouse gases 

  d.. 2012 was ninth warmest year on record with temperatures significantly 
above long-term average 

  e.. Soot causes twice as much global warming as previously thought 


There will be a dramatic global decline in the number of animal and plant 
species this century if the world continues to procrastinate over measures to 
cut carbon dioxide emissions to limit climate change, a study has found.

Current CO2 emissions are currently tracking on the highest trajectory 
envisaged by climate scientists. That means if nothing is done to reduce 
emissions significantly over the coming decades, over half of common plants and 
one-third of the animals could see a serious decline, the study concluded.

Scientists came to the assessment by estimating the current and future 
geographical ranges of nearly 50,000 widespread and common species to see how 
rising temperatures are likely to affect their territorial limits as defined by 
the sort of climate they are adapted to live in.

Plants, amphibians such as frogs and toads, and reptiles such as lizards are 
the groups that are likely to suffer the most from a changing climate because 
of their relative vulnerability to rising temperatures and inability to move 
rapidly from one territory to another, the study found.

It is one of the first detailed assessments of how common species found over 
wide regions of the world will be able to cope with climate change. Many of 
these animals and plants are important because they perform fundamental 
“ecosystem services” such as cleaning up water supplies and decomposing waste 
produce. “This research predicts that climate change will greatly reduce the 
diversity of even very common species found in most parts of the world. This 
loss of global-scale biodiversity would significantly impoverish the biosphere 
and the ecosystem services it provides,” said Rachel Warren, of the University 
of East Anglia, who led the research.

“We looked at the effect of rising global temperatures, but other symptoms of 
climate change such as extreme weather events, pests and diseases mean that our 
estimates are probably conservative. Animals in particular may decline more as 
our predictions will be compounded by a loss of food from plants. There will 
also be a knock-on effect for humans because these species are important for 
things like water and air purification, flood control, nutrient cycling and 
eco-tourism.”

The study found that prompt and stringent mitigation – measures to reduce CO2 
emissions – could substantially avert the biodiversity disaster facing the 
planet. The quicker these measures are enacted, the more time that plants and 
animals will have to adapt to any unavoidable rise in temperatures, says the 
study published in the journal Nature Climate Change. “Our research provides 
crucial new evidence of how swift action to reduce CO2 and other greenhouse 
gases can prevent the biodiversity loss by reducing the amount of global 
warming to 2C rather than 4C,” Dr Warren said.


[Non-text portions of this message have been removed]

Kirim email ke