Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Worldwide fires during the 1997-98 El Niño resulted in high emissions of greenhouse gases

06.01.2004


New study suggests El Niño-related fires may be significant source of greenhouse gases



In 1997-98, while California was ravaged by rainfall in one of the strongest El Niños of the last century, several other regions of the Earth suffered severe droughts, which led to large-scale fires.

James Randerson, assistant professor of Earth system science at UC Irvine, and colleagues report that by combining satellite data and measurements of atmospheric gases, they have quantified for the first time the amount of greenhouse gases, like carbon dioxide and methane, emitted by these fires.


The researchers found that fire emissions of greenhouse gases increased across multiple continents in 1997-98, including an increase of 60 percent in Southeast Asia, 30 percent in Central and South America, and 10 percent in the boreal forests of North America and Eurasia. Study results appear in the Jan. 2, 2004, issue of Science.

“Vast areas of the tropics dry out and become vulnerable to fire during El Niño events,” Randerson said. “It appears that El Niño events accelerate carbon loss from terrestrial ecosystems because they enable humans to use fire more effectively as a tool for clearing land in the tropics.”

The study is another step toward more fully understanding the carbon cycle – the movement of carbon in its many forms in the biosphere – and its effect on climate.

Previous studies have suggested that global warming increases the microbial activity that decomposes plants, releasing more carbon dioxide from soils. Carbon dioxide, one of the forms of carbon, is a greenhouse gas which, when released into the atmosphere, helps raise the Earth’s temperature. The new study suggests that future carbon dioxide levels in the atmosphere may actually be more sensitive to the intensity and variability of El Niños than to increased microbial activity caused by warming.

The researchers also found that large-scale fires contributed to most of the year-to-year changes in atmospheric carbon dioxide totals during the period from 1997 to 2001. “Many scientists have attributed this variability to changes in the balance between plant growth and microbial activity,” Randerson said. “Our work indicates, however, this has a smaller impact on atmospheric carbon dioxide levels than previously believed.”

In addition, the scientists determined that almost all of the increased levels of methane measured during 1997 and 1998 can be attributed to the worldwide fires at the time, underscoring the impact El Niño has on methane emissions.

The study, funded by the NASA’s Office of Earth Science, also provides evidence that areas in southern Mexico and Guatemala experienced large scale increases in fire emissions during the 1997-98 El Niño.

“An important next step is to identify the processes that contributed to the high fire emissions, including deforestation, pasture maintenance, agricultural waste burning and savanna fires,” Randerson said. “This will help us understand how quickly greenhouse gases like carbon dioxide and methane will accumulate in the atmosphere.”

With other researchers in the UCI Department of Earth System Science, Randerson has embarked on a project to study the recent fires in California. Currently, he is conducting field work to study the impact of fires on forests in Alaska and Siberia.

Randerson’s colleagues in the El Niño study include Guido R. van der Werf, G. James Collatz and Louis Giglio of the NASA-Goddard Space Flight Center; Prasad S. Kasibhatla and Avelino F. Arellano Jr. of Duke University; Seth Olsen of California Institute of Technology; and Eric S. Kasischke of the University of Maryland.

About the University of California, Irvine: The University of California, Irvine is a top-ranked public university dedicated to research, scholarship and community. Founded in 1965, UCI is among the fastest-growing University of California campuses, with more than 23,000 undergraduate and graduate students and about 1,300 faculty members. The third-largest employer in dynamic Orange County, UCI contributes an annual economic impact of $3 billion.

Iqbal Pittalwala | UCI
Further information:
http://today.uci.edu/news/release_detail.asp?key=1077

More articles from Earth Sciences:

nachricht Atmospheric scientists reveal the effect of sea-ice loss on Arctic warming
11.03.2019 | Institute of Atmospheric Physics, Chinese Academy of Sciences

nachricht Sensing shakes
11.03.2019 | University of Tokyo

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

Im Focus: Sensing shakes

A new way to sense earthquakes could help improve early warning systems

Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...

Im Focus: A thermo-sensor for magnetic bits

New concept for energy-efficient data processing technology

Scientists of the Department of Physics at the University of Hamburg, Germany, detected the magnetic states of atoms on a surface using only heat. The...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Heading towards a tsunami of light

19.03.2019 | Physics and Astronomy

Dalian Coherent Light Source reveals hydroxyl super rotors from water photochemistry

19.03.2019 | Life Sciences

From foam to bone: Plant cellulose can pave the way for healthy bone implants

19.03.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>