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MU Scientist Finds Late Cretaceous Period Was Likely Ice-free

Study results could foreshadow earth’s future climate, MU researcher says

COLUMBIA, Mo. – For years, scientists have thought that a continental ice sheet formed during the Late Cretaceous Period more than 90 million years ago when the climate was much warmer than it is today. Now, a University of Missouri researcher has found evidence suggesting that no ice sheet formed at this time. This finding could help environmentalists and scientists predict what the earth’s climate will be as carbon dioxide levels continue to rise.

“Currently, carbon dioxide levels are just above 400 parts per million (ppm), up approximately 120 ppm in the last 150 years and rising about 2 ppm each year,” said Ken MacLeod, a professor of geological sciences at MU. “In our study, we found that during the Late Cretaceous Period, when carbon dioxide levels were around 1,000 ppm, there were no continental ice sheets on earth. So, if carbon dioxide levels continue to rise, the earth will be ice-free once the climate comes into balance with the higher levels.” (more…)

Researchers Find Unprecedented, Man-Made Trends in Oceans Acidity

By Guest PostJanuary 26, 2012Environment21st century, acidity, anthropogenic co2 emission, aragonite, aragonite saturation, axel timmermann, bishop museum, calcification rate, calcium carbonate, caribbean, climate, climate modeler, co2 emission, computer modeling, coral, coral reef, earth system model, ecosystem, fossil fuel, global scale, hawaiian islands, honolulu, jamstec, jhamandas watumull planetarium, last glacial maximum, level of acidity, marine ecosystem, marine organism, mollusk, observation, ocean, ocean acidification, ocean chemist, ocean condition, parts per million, ppm, saturation level, tobias friedrich, western equatorial pacific, yellow tangs

Nearly one-third of CO2 emissions due to human activities enters the world’s oceans. By reacting with seawater, CO2 increases the water’s acidity, which may significantly reduce the calcification rate of such marine organisms as corals and mollusks, resulting in the potential loss of ecosystems. The extent to which human activities have raised the surface level of acidity, however, has been difficult to detect on regional scales because it varies naturally from one season and one year to the next, and between regions, and direct observations go back only 30 years.

By combining computer modeling with observations, an international team of scientists concluded that anthropogenic CO2 emissions, resulting from the influence of human beings, over the last 100 to 200 years have already raised ocean acidity far beyond the range of natural variations. The study is published in the January 22, 2012 online issue of Nature Climate Change. (more…)

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MU Scientist Finds Late Cretaceous Period Was Likely Ice-free

Researchers Find Unprecedented, Man-Made Trends in Oceans Acidity