Environmental Sciences Commons^™

Maine's Climate Future: An Initial Assessment, George L. Jacobson, Ivan J. Fernandez, Paul Andrew Mayewski, Catherine V. Schmitt

Earth Science Faculty Scholarship

Earth’s atmosphere is experiencing unprecedented changes that are modifying global climate. Discussions continue around the world, the nation, and in Maine on how to reduce and eventually eliminate emissions of carbon dioxide (CO2), other greenhouse gases, and other pollutants to the atmosphere, land, and oceans. These efforts are vitally important and urgent. However, even if a coordinated response succeeds in eliminating excess greenhouse gas emissions by the end of the century, something that appears highly unlikely today, climate change will continue, because the elevated levels of CO2 can persist in the atmosphere for thousands of years to come.

In late …

Ice Core Record Of Rising Lead Pollution In The North Pacific Atmosphere, E. Osterberg, Paul Andrew Mayewski, Karl J. Kreutz, D. Fisher, Michael Handley, Sharon Sneed, C. Zdanowicz, J. Zheng, M. Demuth, M. Waskiewicz, J. Bourgeois

Earth Science Faculty Scholarship

A high-resolution, 8000 year-long ice core record from the Mt. Logan summit plateau (5300 m asl) reveals the initiation of trans-Pacific lead (Pb) pollution by ca. 1730, and a >10-fold increase in Pb concentration (1981–1998 mean = 68.9 ng/l) above natural background (5.6 ng/l) attributed to rising anthropogenic Pb emissions from Asia. The largest rise in North Pacific Pb pollution from 1970–1998 (end of record) is contemporaneous with a decrease in Eurasian and North American Pb pollution as documented in ice core records from Greenland, Devon Island, and the European Alps. The distinct Pb pollution history in the North Pacific …

Glaciochemical Investigations As A Tool In The Historical Delineation Of The Acid Precipitation Problem, William B. Lyons, Paul Andrew Mayewski

Earth Science Faculty Scholarship

Precipitation in the Northern Hemisphere has been recently recognized to have hydrogen ion concentrations 10 to 100 times higher than expected for natural precipitation (Likens and Bormann 1974, Cogbill and Likens 1974, Lewis and Grant 1980). However, controversy has arisen regarding the nature of the acidity of the precipitation sampled and whether, indeed, the pH of North American precipitation has increased over time (Miller and Everett 1979, Lerman 1979, Stensland 1980, Sequeria 1981, Carlson and Rodhe 1982). In most locations pH records have been constructed rather imperfectly due to differences in sampling, handling, and analytical procedures used (Galloway and Likens …

Nitrate Plus Nitrite Concentrations In A Himalayan Ice Core, William Berry Lyons, Paul Andrew Mayewski

Earth Science Faculty Scholarship

The measurement of chemical constituents in glacial ice has been useful in discerning historic trends in chemical deposition and hence paleo-atmospheric records in remote areas (Thompson and Mosley - Thompson, 1981; Johnson and Chamberlain, 1981; Ng and Patterson, 1981; Neftel et al., 1982). However, delineating the sources of the deposited chemical species in question is not always straightforward. This has been especially true for nitrate. Although it is now believed that man-made emissions are responsible for a high percentage of nitrate being deposited in remote areas of the Northern Hemisphere, numerous natural sources, named and unnamed, have also contributed to …