Scientists from the Desert Research Institute (DRI) and their collaborators have determined that Northern Hemisphere industrial pollution resulted in a seven-fold increase in black carbon (soot) in Arctic snow during the late 19th and early 20th centuries, according to new research into the impact of black carbon on Arctic climate forcing.
The study in the August 9th online edition of Science magazine was led by Drs. Joe McConnell and Ross Edwards—two ice core scientists from DRI—who used a new method for measuring soot in snow and ice to evaluate historical changes in soot concentrations using an ice core from the Greenland Ice Sheet. At its maximum from 1906 to 1910, estimated early summer surface climate forcing from black carbon in Arctic snow was eight times that of the pre-industrial era.
Soot reduces reflectivity of snow and ice—decreasing its albedo in scientific terms—allowing the surface to absorb more energy from the sun. Changes in highly reflective seasonal snow covers may have resulted in earlier snow melt and exposure of much darker underlying soil, rock, and sea ice throughout the Arctic—leading to warming across much of this region in the late 19th and early 20th centuries. For the Greenland ice sheet, these findings are significant because it is the largest ice mass in the northern hemisphere and darkening of the surface by soot from combustion of biomass and fossil fuels accelerates melting and increases sensitivity to warming.
In an article published in the August 9th online edition of Science magazine, a team of National Science Foundation- and NASA-funded researchers from DRI, the University of California, the University of Wisconsin, and Droplet Measurement Technologies report results of this novel ice-core analysis and modeling effort. Their measurements of deposition during the past two centuries, combined with modeling, reveal that the source of most of the black carbon landing on the ice changed from natural causes such as forest fires to industrial sources. The amount of black carbon deposited during this period increased precipitously, reaching a peak around 1910.
“Concentrations of black carbon varied significantly from 1788 to 2002 and were highly seasonal, particularly during the period before the Industrial Revolution in North America in the mid-1800s,” said lead author Joe McConnell. “Starting in about 1850, soot concentrations began to rise, particularly in winter when forest fire emissions are at a minimum,” McConnell added.
“In addition to black carbon, we measured a broad range of other chemicals at very high depth resolution in this same ice core,” said Joe McConnell. “Two of these ancillary measurements, vanillic acid and sulfur, are indicators of forest fire and industrial emissions, respectively. When we compare changes in the black carbon to changes in these other indicators, it is clear that most of the increases in black carbon in the late 19th and early 20th centuries, particularly in winter and spring, resulted from industrial emissions - probably from coal burning.”
Co-author Ross Edwards added, “In order to understand why Arctic climate is changing so rapidly at present, we need to understand how and why it has changed both before and after human activities had an influence on climate. To do this properly, we need to know the seasonal history of soot deposition and its impact on Arctic snow albedo during the past few centuries. Our results allow this component of climate change to be incorporated into predictive climate models in a more realistic way.”
By tracking the possible trajectories of major snowfall events that would have transported and deposited the black carbon to largely undeveloped Greenland, the researchers conclude that industrial areas of the United States and Canada were the most likely sources of the increased deposition during the past century. Boreal forest fires in northern and eastern Canada and the United States were the likely sources of natural black carbon found in the ice core.
“We used computer models to simulate the climate forcing impact of the observed changes in soot concentrations in Greenland snow during the past 215 years,” said co-author Mark Flanner from the University of California and now at the National Center for Atmospheric Research. Simulations also were used to extend the climate forcing results from central Greenland to the entire Arctic based on regional-scale models. From these simulations, the average impact from soot pollution over the Arctic was about double that found for central Greenland. Early summer climate forcing throughout the Arctic during and after industrialization was substantial, with changes largely attributed to winter-time pollution.Â In the peak period from 1906 to 1910, the warming effect of the industrial soot throughout the Arctic was estimated at eight times that during the pre-industrial period.
Greg Bortolin | EurekAlert!
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
Urbanization to convert 300,000 km2 of prime croplands
27.12.2016 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering