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!
WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf
First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences