2C warming goal now 'optimistic' - French scientists

Feb 09, 2012
Snow falls on flowers in New York City, in 2011. French scientists unveiling new estimates for global warming said on Thursday the 2 C (3.6 F) goal enshrined by the United Nations was "the most optimistic" scenario left for greenhouse-gas emissions.

French scientists unveiling new estimates for global warming said on Thursday the 2 C (3.6 F) goal enshrined by the United Nations was "the most optimistic" scenario left for greenhouse-gas emissions.

The estimates, compiled by five scientific institutes, will be handed to the UN's (IPCC) for consideration in its next big overview on global warming and its impacts.

The report -- the fifth in the series -- will be published in three volumes, in September 2013, March 2014 and April 2014.

The French team said that by 2100, warming over pre-industrial times would range from two degrees Celsius (3.6 degrees Fahrenheit) to 5.0 C (9.0 F).

The most pessimistic scenarios foresee warming of 3.5-5.0 C (6.3-9.0 F), the scientists said in a press release.

Achieving 2C, "the most optimistic scenario," is possible but "only by applying climate policies to reduce ," they said.

In its Fourth Assessment Report published 2007, the IPCC said Earth had already warmed in the 20th century by 0.74 C (1.33 F).

It predicted additional warming in the 21st century of 1.1-6.4 C (1.98-11.52 F), of which the likeliest range was 1.8-4.0 C (3.24-7.2 F).

The French estimates are derived from two different computer models that crunch data for four scenarios based on atmospheric levels of carbon dioxide (CO2), the main greenhouse gas.

The work differs from previous calculations as it takes into account the of clouds and uptake of CO2 by the oceans and other factors that can skew the equation, the authors said.

Meeting in Cancun, Mexico in December 2010, countries under the (UNFCCC) set 2 C (3.6 F) above pre-industrial times as the maximum limit for warming.

They vowed to consider lowering it to 1.5 C (2.7 F) if scientific evidence warranted this.

Small island states and other poor nations badly exposed to are lobbying for the 1.5 C (2.7 F) limit.

Explore further: EPA staff says agency needs to be tough on smog

add to favorites email to friend print save as pdf

Related Stories

Scientists warn of climate catastrophe

Jun 18, 2009

The world faces a growing risk of "abrupt and irreversible climatic shifts" as fallout from global warming hits faster than expected, according to research by international scientists released Thursday.

New carbon dioxide emissions model

Aug 02, 2010

Meteorologists have determined exactly how much carbon dioxide humans can emit into the atmosphere while ensuring that the Earth does not heat up by more than two degrees.

Recommended for you

Shell files new plan to drill in Arctic

Aug 29, 2014

Royal Dutch Shell has submitted a new plan for drilling in the Arctic offshore Alaska, more than one year after halting its program following several embarrassing mishaps.

Reducing water scarcity possible by 2050

Aug 29, 2014

Water scarcity is not a problem just for the developing world. In California, legislators are currently proposing a $7.5 billion emergency water plan to their voters; and U.S. federal officials last year ...

User comments : 0