Action by 2020 key to keep global warming below 2 degrees
Washington ,
Mon, 17 Dec 2012
ANI
Washington, December 17 (ANI): Limiting climate change to target
levels will become much more difficult to achieve, and more expensive,
if action is not taken soon, a new analysis has revealed.
The
study from IIASA, ETH Zurich, and NCAR explores technological, policy,
and social changes that would need to take place in the near term in
order to keep global average temperature from rising above 2 degree C, a
target supported by more than 190 countries as a global limit to avoid
dangerous climate change.
This study for the first time
comprehensively quantifies the costs and risks of greenhouse gas
emissions surpassing critical thresholds by 2020. The findings of the
study are particularly important given the failure of the recent climate
negotiations in Doha to decide to increase mitigation action before
2020.
The researchers revealed that the 2 degree C target could
still be reached even if greenhouse gas emissions are not reduced before
2020, but only at very high cost, with higher climate risks, and under
exceedingly optimistic assumptions about future technologies.
The
more emissions are reduced in the near term, the more options will be
available in the long run and, by extension, the cheaper it will be to
reach international climate targets.
"We wanted to know what
needs to be done by 2020 in order to be able to keep global warming
below two degrees Celsius for the entire twenty-first century," said
Joeri Rogelj, lead author of the paper and researcher at ETH Zurich.
The
team of researchers analyzed a large array of potential scenarios for
limiting global temperature rise to 2 degree C above preindustrial
levels, a target set by international climate agreements.
Projections
based on current national emissions pledges suggest that global carbon
dioxide equivalent (CO2e) emissions will reach 55 gigatons (billion
metric tons, Gt) or more per year in 2020, up from approximately 50 Gt
today. At such levels, it would still be possible to reach the 2 degree C
target in the long term, though it would be more difficult and
expensive than if near-term emissions were lower.
For instance,
nuclear power would need to remain on the table as a mitigation option,
or people would need to quickly adopt advanced technology strategies,
including electric vehicles and highly efficient energy end-use
technologies such as appliances, buildings, and transportation.
Meanwhile,
coal-fired power plants would need to be rapidly shut down and replaced
with other energy sources. IIASA Energy Program Leader Keywan Riahi,
who also worked on the study, said, "You would need to shut down a coal
power plant each week for ten years if you still wanted to reach the
two-degree Celsius target."
According to the study, the only way
to meet the long-term temperature target without carbon capture and
storage is to ensure that emissions fall within this near-term range.
"Our
analysis shows that we are very dependent on key technologies like
carbon capture and storage and on land-consuming measures like
afforestation and the cultivation of crops for biofuel production," said
Rogelj.
"If we want to become less dependent on massive
implementation of these technologies to make it below two degrees
Celsius, we need to reduce emissions by 2020 and use energy more
efficiently," he noted.
The new paper has been published in Nature Climate Change. (ANI)
