Forum for Science, Industry and Business

First direct observations of methane's increasing greenhouse effect at the Earth's surface

These findings were published online April 2 in the journal Nature Geoscience in an article entitled "Observationally derived rise in methane surface forcing mediated by water vapour trends." The paper indicates that the greenhouse effect from methane tracked the global pause in methane concentrations in the early 2000s and began to rise at the same time that the concentrations began to rise in 2007.

The scientists used radiometers, shown here, to isolate the signal of methane's greenhouse effect. Radiometers are among the many instruments at ARM's Southern Great Plains observatory that the team utilized as part of this study.

Credit: ARM Climate Research Facility

This graph shows a time series of the greenhouse effect of methane in Watts per square meter, measured at the Earth's surface over a ten-year period at a research site in northern Oklahoma. The red line is the trend in the time series, and the grey shading represents uncertainty.

Credit: Berkeley Lab

"We have long suspected from laboratory measurements, theory, and models that methane is an important greenhouse gas," said Berkeley Lab Research Scientist Dan Feldman, the study's lead author. "Our work directly measures how increasing concentrations of methane are leading to an increasing greenhouse effect in the Earth's atmosphere."

Gases that trap heat in the atmosphere are called greenhouse gases, in large part because they absorb certain wavelengths of energy emitted by the Earth. As their atmospheric concentrations change, the scientific community expects the amount of energy absorbed by these gases to change accordingly, but prior to this study, that expectation for methane had not been confirmed outside of the laboratory.  

The scientists analyzed highly calibrated long-term measurements to isolate the changing greenhouse effect of methane. They did this by looking at measurements over the wavelengths at which methane is known to exert its greenhouse effect and coupled those with a suite of other atmospheric measurements to control for other confounding factors, including water vapor.

This study was enabled by the comprehensive measurements of the Earth's atmosphere that the DOE has routinely collected for decades at its Atmospheric Radiation Measurement (ARM) facilities, and conversely, would not be possible without such detailed observations.

The DOE ARM program manages and supports three long-term atmospheric observatories - the Southern Great Plains observatory in Oklahoma, the North Slope of Alaska observatory in far-northern Alaska, and the Eastern North Atlantic observatory on the Azores Islands. The program also deploys three ARM mobile facilities and several ARM aerial facilities. Together, these assets enable scientists to perform highly-detailed, targeted investigations to advance the fundamental scientific understanding of the Earth system.

The researchers believe this type of direct field observation can provide a more accurate and complete picture of the relationship between atmospheric greenhouse gas concentrations and their warming effect on Earth's surface.

###

The research was funded by the Department of Energy's Office of Science.

Lawrence Berkeley National Laboratory addresses the world's most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab's scientific expertise has been recognized with 13 Nobel Prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy's Office of Science. For more, visit http://www.lbl.gov.

DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

Dan Krotz | EurekAlert!
Further information:
https://www.eurekalert.org/pub_releases/2018-04/dbnl-fdo033018.php

Im Focus: Why we need erasable MRI scans

New technology could allow an MRI contrast agent to 'blink off,' helping doctors diagnose disease

Magnetic resonance imaging, or MRI, is a widely used medical tool for taking pictures of the insides of our body. One way to make MRI scans easier to read is...

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...