Where's the Ice?
April 7, 2006
by Dennis T. Avery
The climate modelers and their embedded journalists have run riot in recent weeks claiming that the world will be flooded with meltwater from the Antarctic ice cap. They blame warming from unrepentant humans loading the atmosphere with auto exhaust.
The University of Arizona’s Jonathon Overpeck says extreme warming may melt enough Antarctic ice to raise sea levels by 20 feet. That would permanently flood cities like New Orleans and low-lying countries like Bangladesh, he says.
Mr. Overpeck points to a sudden sea level rise of 20 feet during a global warming 130,000 years ago—which he speculates melted part of the Antarctic ice cap. He says the Antarctic may now again melt quickly.
Mr. Overpeck could have made his claim much more dramatic. Twenty feet is puny. In reality, global sea levels actually rose a whopping 400 feet 130,000 years ago—in a few centuries—because the Earth was making one of its major, sudden shifts from a full-blown Ice Age into the Eemian warm period!
The Ice Age had locked huge amounts of the Earth’s water into ice sheets, up to a mile thick, covering some 10 million square miles of North America and the former Soviet Union. The sudden temperature shift quickly melted those ice sheets, but there is no evidence it melted the Antarctic.
Actually, Mr. Overpeck’s supposedly scary Eemian sea levels were roughly the same level as we have now. After the quick melting, there wasn’t much other ice left on Earth then, and there isn’t today. Our ice melt has become so scanty that it’s currently raising sea levels only 4 inches per century—with no increase in the last 100 years despite the Modern Warming. That’s not very alarming.
It would take another 7000 years at current rates to melt the Antarctic ice cap, says the University of Washington’s Dr. John Stone. That’s because the Antarctic ice is so thick, the polar temperatures never get very high, and the ice resists melting by reflecting sunlight away. Such a melting is unlikely, since our next global cooling is due in about 500–700 years.
Another problem for Mr. Overpeck: Except for the tiny Antarctic Peninsula, satellites and surface thermometers both show Antarctica has cooled slightly for the past 40 years.
The edges of the Greenland ice sheet are melting near the water—but that’s exactly what happened 1000 years ago when the Vikings established colonies there. Greenland and the world were entering the moderate Medieval Warming, which raised temperatures in Europe about 1 degree C. The Vikings saw enough pasture for their dairy cattle, and thrived for 300 years. They didn’t drown in rising seas.
Then, however, the Medieval Warming cycled into the Little Ice Age. Temperatures fell 2 degrees C or so, and the sea ice imprisoned the Vikings. They couldn’t grow enough hay in shorter summers to feed their cattle through longer winters. They froze or they starved, victims of the Earth’s natural, moderate climate cycle.
Long ice cores from both Greenland and the Antarctic tell us that Earth has had 600 warming cycles in the last million years. None were driven by human-emitted CO2. The carbon and beryllium isotopes in the ice show, instead, that the climate cycles have been linked to changes in the sun’s irradiance.
The U.N. Intergovernmental Panel on Climate Change claims they found a “human fingerprint” on our warming. But they’ve offered no evidence. Just a brief period of correlation between observed data and the models between 1943 and 1970—out of a century-long data set.
Dennis T. Avery is based in Churchville, VA, and is director of the Hudson Institute's Center for Global Food Issues.