Man as God: Returning the atmosphere to the way it was nearly 5 million years ago
Earth's greenhouse gas levels approach 400-ppm milestone
By Geoffrey Mohan, Los Angeles Times
5:25 AM PDT, May 1, 2013
The ratio of carbon dioxide in Earth’s atmosphere is flirting with 400 parts per million, a level last seen about 2.5 million to 5 million years ago, according to the Scripps Institution of Oceanography at UC San Diego.
The Institution this week launched a daily Keeling curve update, showing the saw-toothed upward diagonal of rising carbon dioxide levels since the late 1950s.
Isolated measurements have peaked at above 400 parts per million in the Arctic, but scientists are more alarmed at steady readings from Mauna Loa, Hawaii, far from major pollution sources. Those measurements, considered to be the most reliable indicators of Earth's atmospheric content, could breach the 400 level this month, according to Scripps.
The speed at which Earth’s atmosphere has reached that density of carbon dioxide, a known greenhouse gas, has scientists alarmed.
Scientists estimate that average temperatures during the Pliocene rose as much as 18 degrees Fahrenheit. Sea levels during that 2.8-million-year epoch ranged between 16-131 feet higher than current levels, according to Richard Norris, a Scripps geologist.
“I think it is likely that all these ecosystem changes could recur, even though the time scales for the Pliocene warmth are different than the present,” Norris said. Heating the ocean probably will cause sea level rises and change the Ph balance of the ocean, affecting a wide array of marine life, he said. “Our dumping of heat and CO2 into the ocean is like making investments in a pollution bank,” he said.
(Continued here. See also "Global carbon dioxide levels near worrisome milestone" in Nature and "As CO2 Approaches Symbolic Milestone, Scripps Launches Daily Keeling Curve Update" from Scripps Institution of Oceanography.)
By Geoffrey Mohan, Los Angeles Times
5:25 AM PDT, May 1, 2013
The ratio of carbon dioxide in Earth’s atmosphere is flirting with 400 parts per million, a level last seen about 2.5 million to 5 million years ago, according to the Scripps Institution of Oceanography at UC San Diego.
The Institution this week launched a daily Keeling curve update, showing the saw-toothed upward diagonal of rising carbon dioxide levels since the late 1950s.
Isolated measurements have peaked at above 400 parts per million in the Arctic, but scientists are more alarmed at steady readings from Mauna Loa, Hawaii, far from major pollution sources. Those measurements, considered to be the most reliable indicators of Earth's atmospheric content, could breach the 400 level this month, according to Scripps.
The speed at which Earth’s atmosphere has reached that density of carbon dioxide, a known greenhouse gas, has scientists alarmed.
Scientists estimate that average temperatures during the Pliocene rose as much as 18 degrees Fahrenheit. Sea levels during that 2.8-million-year epoch ranged between 16-131 feet higher than current levels, according to Richard Norris, a Scripps geologist.
“I think it is likely that all these ecosystem changes could recur, even though the time scales for the Pliocene warmth are different than the present,” Norris said. Heating the ocean probably will cause sea level rises and change the Ph balance of the ocean, affecting a wide array of marine life, he said. “Our dumping of heat and CO2 into the ocean is like making investments in a pollution bank,” he said.
(Continued here. See also "Global carbon dioxide levels near worrisome milestone" in Nature and "As CO2 Approaches Symbolic Milestone, Scripps Launches Daily Keeling Curve Update" from Scripps Institution of Oceanography.)
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