Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists outline strategy to limit global warming

05.05.2010
Efforts range from 'Herculean' to achievable

Major greenhouse gas-emitting countries agreed in the December, 2009, climate talks in Copenhagen that substantial action is required to limit the increase of the global average temperature to less than 2 degrees Celsius (3.6 degrees Fahrenheit).

In a paper appearing May 3 in the journal Proceedings of the National Academy of Sciences (PNAS), Veerabhadran Ramanathan and Yangyang Xu, climate researchers at Scripps Institution of Oceanography, University of California, San Diego, have identified three avenues by which the major greenhouse gas-emitting countries countries can avoid reaching the warming threshold. This threshold is a point beyond which many scientists believe climate change will present unmanageable negative consequences for society.

Researchers suggest that exceeding this threshold would trigger irreversible phenomena such as widespread release of methane from melting permafrost and large-scale glacial melt. In turn, these would exacerbate climate change-related problems such as sea-level rise and acceleration of global warming.

"Without an integrated approach that combines carbon dioxide emission reductions with reductions in other climate warmers, and without climate-neutral air pollution laws, we are certain to pass the 2 C threshold during this century," said Ramanathan. However, he added, "I am delighted by the availability of several 'low-hanging fruits' that can help us avert unmanageable climate changes."

Using a synthesis of National Science Foundation (NSF)-funded research performed over the last 20 years, Ramanathan and Xu describe three steps that must be taken to avoid the threshold. They stress that carbon dioxide control alone is not enough.

"The low-hanging fruits approach to one of mankind's great challenges is very appealing because it's win-win," said Jay Fein, program director in NSF's Division of Atmospheric and Geospace Sciences. "It cleans up the environment, protects human health and helps to sustain the 2 C threshold."

The first and second recommended steps in the PNAS paper include stabilizing carbon dioxide concentrations in the atmosphere; and fashioning warming-neutral pollution laws. These laws would balance the removal of aerosols that have an atmospheric cooling effect with the removal of warming agents such as soot and ozone.

Thirdly, the authors advocate achieving immediate cooling through reductions in methane, hydrofluorocarbons and other greenhouse gases that last in the atmosphere for short periods of time.

They believe that simultaneous pursuit of these strategies could reduce the probability of reaching the temperature threshold to less than 10 percent before the year 2050.

The 2 degrees Celsius global temperature increase limit translates to a radiant energy increase of 2.5 watts per square meter. Ramanathan and Xu note that even if greenhouse gas emissions stop increasing in the next five years, human activities will probably create almost double that much radiant energy.

That excess radiant energy, however, is partially compensated for by the masking effect of certain kinds of aerosols that are produced in large part by pollution.

Tiny particles of sulfates and other pollutants serve to cool the atmosphere by reflecting sunlight rather than absorbing it, directing heat away from the Earth's surface.

Therefore, the authors state, pollution control measures must take into account and counterbalance the warming that will happen when these pollutants are removed from the skies.

Ramanathan and Xu acknowledge that there are uncertainties about the nature of aerosols, and the sensitivity of climate to mitigation actions, that make the effects of their suggested course of action hard to determine with precision.

They propose demonstration projects to clarify and reduce the uncertainties, and verify the effectiveness of the various mitigation avenues proposed.

Avoiding the warming threshold requires holding carbon dioxide levels to less than 441 parts per million (ppm), according to the authors, only slightly higher than today's 389 ppm.

This equates to a 50-percent reduction in greenhouse gas emissions by 2050 and an 80 percent reduction by 2100. Ramanathan and Xu acknowledge that such drastic reduction will require a "portfolio of actions in the energy, industrial, agricultural, and forestry sections."

Some of these actions will require development of new technologies.

"A massive decarbonization of the energy sector is necessary to accomplish this Herculean task," the authors write.

But strategies not focused on carbon dioxide reduction can largely take advantage of existing technologies and enforcement of existing regulations, say the authors.

Actions that can be taken immediately include replacement of biomass-fueled stoves with cleaner alternatives in developing countries, and retrofitting of diesel filters on vehicles throughout the world.

The authors also point out that the world has succeeded before in removing dangerous warming agents.

The 1987 Montreal Protocol regulated the use of chlorofluorocarbons; the damaging effect of the chemicals on the planet's ozone layer was diminished.

Ramanathan and Xu note that were it not for the Montreal Protocol, the warming effect of chlorofluorocarbons would have added between 0.6 and 1.6 watts per square meter of extra heat energy by now.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Ecology, The Environment and Conservation:

nachricht Species may appear deceptively resilient to climate change
24.11.2017 | University of California - Davis

nachricht Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>