Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Ozone-destroying gas in atmosphere increased significantly during Industrial Age, study shows


By examining trapped air bubbles in an ice core, researchers extend atmospheric record of methyl bromide over 300 years

Photograph by: Melanie Conner, National Science Foundation

Human activity in the Industrial Age – approximately the last 150 years – has significantly increased atmospheric levels of methyl bromide, a gas known for harming the ozone layer in the Earth’s stratosphere.

A research team led by UC Irvine scientist Eric Saltzman reached this conclusion after examining an ice core recovered from Antarctica. By studying air bubbles trapped in the core, Saltzman’s team was able to compare levels of methyl bromide in the atmosphere over the last three centuries. The team concluded that during the industrial era, the amount of global atmospheric methyl bromide in Southern Hemisphere air appears to have increased by 3.5 parts per trillion, or approximately 50 percent of the preindustrial level of the gas.

The researchers report their findings in the March 2, 2004, issue of the Journal of Geophysical Research – Atmospheres.

In the study, the researchers utilized 23 samples of shallow ice core drilled in 1995 in Siple Dome, West Antarctica, as part of a National Science Foundation-sponsored ice coring project in the West Antarctic ice sheet. Air was extracted from the samples in Saltzman’s laboratory at UCI and analyzed using gas chromatography/mass spectrometry, a powerful analytical technique.

“We found trace levels of methyl bromide dating back to the late 1600s in the core’s air bubbles,” said Saltzman, professor of Earth system science. “This longer-term record of methyl bromide shows convincingly that the amount of methyl bromide in the atmosphere increased during the industrial era. The reconstruction of ancient atmospheric levels of methyl bromide is an exciting development. Ice core records can provide insights into the natural variability of methyl bromide and shed light on how sensitive its atmospheric cycle is to climate change.”

Previous records of methyl bromide in the atmosphere – a compilation of instrumental records and firn air measurements – had only extended back to about the year 1900. (Firn is rounded, well-bonded snow that is older than one year.)

The researchers also developed a numerical model to simulate major processes involved in the global biogeochemical cycle of methyl bromide. Both the ice core measurements and modeling results show that human activities such as fumigation, combustion and biomass burning in industrial times have significantly increased atmospheric levels of this gas. “They also highlight the large uncertainty still remaining in our understanding of the modern atmospheric methyl bromide budget,” Saltzman said.

Methyl bromide is a fumigant used to control insects, nematodes, weeds and pathogens in crops, forests and wood products. Its primary uses are for soil fumigation, postharvest protection and quarantine treatments. The gas also has natural sources in both terrestrial and oceanic environments, as well as natural “sinks” that can remove methyl bromide from the atmosphere. It is the only chemical included in the Montreal Protocol – the international agreement designed to protect the Earth’s stratospheric ozone layer – that has major natural sources. Understanding the natural sources and sinks of methyl bromide is a focus of current research, as is gaining a greater understanding of other gases harming the ozone layer, which protects the Earth from ultraviolet radiation.

Researchers Murat Aydin of UCI; Warren J. De Bruyn of Chapman University, Orange, Calif.; Daniel B. King of Drexel University, Philadelphia, Pa.; and Shari A. Yvon-Lewis of the National Oceanic and Atmospheric Administration, Miami, Fla., also contributed to the study. The research was supported by the National Science Foundation and the National Oceanic and Atmospheric Administration.

Iqbal Pittalwala | UCI
Further information:

More articles from Earth Sciences:

nachricht UCI and NASA document accelerated glacier melting in West Antarctica
26.10.2016 | University of California - Irvine

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

Advanced analysis of brain structure shape may track progression to Alzheimer's disease

26.10.2016 | Health and Medicine

3-D-printed structures shrink when heated

26.10.2016 | Materials Sciences

More VideoLinks >>>