This graph shows estimates of the influences of various factors (greenhouse gases, ozone, aerosols, and other) on climate change over the industrial period, and their combined total influence. Red brackets indicate the range of uncertainty for each factor and the total. The uncertainty for the "total" estimate is so large because of the large uncertainty in the estimated influence of aerosols. Shrinking the uncertainty associated with the total to a value that is useful for interpreting Earths climate sensitivity requires a major reduction in the uncertainty associated with the influence of aerosols.
Climate scientists agree that atmospheric carbon dioxide (CO2) has increased about 35 percent over the industrial period and that it will continue to rise so that CO2 will reach double its pre-industrial value well before the end of this century. How much this doubled CO2 concentration will raise Earth’s global mean temperature, however, remains quite uncertain and is the subject of intense research — and heated debate.
In a paper to be published in the November issue of the Journal of the Air and Waste Management Association, Stephen Schwartz, an atmospheric scientist at the U.S. Department of Energy’s Brookhaven National Laboratory, argues that much of the reason for the present uncertainty in the climatic effect of increased CO2 arises from uncertainty about the influence of atmospheric aerosols, tiny particles in the air. Schwartz, who is also chief scientist of the Department of Energy’s Atmospheric Science Program, points out that aerosols scatter and absorb light and modify the properties of clouds, making them brighter and thus able to reflect more incoming solar radiation before it reaches Earth’s surface.
“Because these aerosol particles, like CO2, are introduced into the atmosphere as a consequence of industrial processes such as fossil fuel combustion,” says Schwartz, “they have been exerting an influence on climate over the same period of time as the increase in CO2, and could thus very well be masking much of the influence of that greenhouse gas.” However, he emphasizes, the influence of aerosols is not nearly so well understood as the influence of greenhouse gases.
Karen McNulty Walsh | EurekAlert!
Despite government claims, orangutan populations have not increased. Call for better monitoring
06.11.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Increasing frequency of ocean storms could alter kelp forest ecosystems
30.10.2018 | University of Virginia
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences