UN climate conference warned that 2 degrees global warming is not 'safe'
1.5 degrees may be a better upper limit for climate change than 2. Credit: david_addimage (iStockphoto)
A report presented to a UN climate conference in Germany warns that global warming limit of 2 degrees Celsius is not 'safe' and proposes a new target of 1.5 degrees.
HAMFUL IMPACTS OF global warming such as heat waves and sea level rise are mounting and show a need for a "radical transition" to a greener economy, said a study presented at United Nations climate talks on Tuesday.
Damage is growing even though average temperatures have risen only 0.85 degrees Celsius above pre-industrial times, less than half the 2°C set as a maximum acceptable rise by almost 200 nations, it said."Negative impacts are not only something in the future — they are something now," said Zou Ji, a co-leader of the UN review of consultations about science policy for governments working on a UN climate deal in Paris in December.
The report, based on talks between experts and governments, was presented the sidelines of June 1 to 11 talks on the Paris accord, taking place in Bonn, Germany. All present at the unveiling of the report said government promises so far for curbs on greenhouse gas emissions were too weak to stay below the 2°C goal.
"Limiting global warming to below 2°C necessitates a radical transition ... not merely a fine tuning of current trends," according to the report.
Such a transition would mean deep cuts in greenhouse gases, shifting from fossil fuels such as coal and oil to renewable energies such as wind, hydro and solar power, it said.
The report also concluded that the 2°C goal was too often wrongly viewed as an acceptable maximum, a 'guardrail' up to which climate change would be manageable.
But impacts of climate change, such as damage to coral reefs or the melting of Greenland's ice that is raising sea levels, showed risks were already increasing.
"The guardrail concept in which up to 2°C would be considered safe would be better seen as an upper limit, a defence line," said Andreas Fischlin, a co-leader of the report.
Thomas Stocker, a senior Swiss scientist from the Intergovernmental Panel on Climate Change, the climate science advisory body to the UN, said governments faced tough choices in managing the risks of warming.
"The elephant in the room is what we can do to change the trend in emissions," he told delegates.
Many developing nations favour setting a ceiling of 1.5°C above pre-industrial times, arguing that their economies are vulnerable to impacts such as storms, floods, droughts and sea level rise.
Collin Beck, representing the Solomon Islands, said scientists should do more to examine ways to set up a defence line against 1.5°C.