January 10th, 2012 by Joshua S Hill
The massive levels of greenhouse gasses left in the atmosphere as a result of human burning of fossil fuels is liable to disrupt normal patterns of glaciation say scientists in a new study.
If humans had not arrived and interrupted things, science tells us that the Earth’s current warm phase would have given way to another ice age in approximately 1,500 years, 12,500 after it had started.
However, and there is always a however, the current levels of carbon dioxide are trapping heat into the atmosphere, prevent the Earth from cooling on schedule.
Good news? Better living conditions for the height of intelligent species to continue on living unhindered by a chill snap? Not so, says Jim Channel, distinguished professor of geology at University of Florida and co-author of the paper published in online January 8 in the journal Nature Geoscience.
“Ice sheets like those in western Antarctica are already destabilized by global warming,” said Channell. “When they eventually slough off and become a part of the ocean’s volume, it will have a dramatic effect on sea level.”
“We know from past records that Earth’s orbital characteristics during our present interglacial period are a dead ringer for orbital characteristics in an interglacial period 780,000 years ago,” said Channell.
But this time around there is more greenhouse gas in the atmosphere than there has been previously, trapping the sun’s heat in and warming the planet. As a result, the normal orbital characteristics which would normally initiate a cooling phase are unable to do so. The carbon levels over the past million years as has been recorded in ice samples has never reached more than 280 parts per million.
“We are now at 390 parts per million,” Channell said, a spike which has only taken place in the last 150 years.
“The problem is that now we have added to the total amount of CO2 cycling through the system by burning fossil fuels,” said Channell. “The cooling forces can’t keep up.”
Channell said that the study brings to the forefront the importance of atmospheric carbon dioxide because it shows the dramatic effect that it is having on a natural cycle that has controlled our Earth’s climate for millions of years.
“We haven’t seen this high concentration of greenhouse gases in the atmosphere for several million years,” Channell said. “All bets are off.”
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