Researchers from the Scripps Oceanographic Institute generated big headlines in recent weeks, claiming they’ve found “the first clear evidence of human-produced warming in the oceans.”
“This is perhaps the most compelling evidence yet that global warming is happening right now and it shows that we can successfully simulate its past and likely future evolution,” said Tim Barnett, a marine physicist at Scripps. He told a panel of the American Association for the Advancement of Science that the Scripps modeling proved recent warming wasn’t caused by the sun or volcanoes.
Actually, what Scripps did was to develop a computer model showing how much the Earth’s surface warming of the last 40 years should have warmed the oceans. Happily for them, that’s about how much warming has been observed in the upper 500-700 feet of the oceans. But how does this explain what caused the warming?
Historically, Scripps has had a gilt-edged reputation.
However, Germany’s Max Planck Institute also has a good science reputation. Ilya Usoskin of the Planck Institute says the sun is now more active than it’s been for 1000 years based on direct measurements of beryllium10 in polar ice cores that go back thousands of years. (Less beryllium 10 in the ice core means a more active sun, and the ice core samples show a lower concentration than in the last millennium.)
Usoskin’s research adds weight to the theory that the Earth’s Modern Warming—since 1850—is produced by the sun’s increased magnetic activity.
History is on the side of the German researcher. History confirms that Earth had a Roman Warming about 2000 years ago, followed by the cold Dark Ages, a Medieval Warming about 1000 years ago, and then a Little Ice Age that ended about 150 years ago.
The physical evidence is also favors the German research. Over the last 20 years, ice cores retrieved from Greenland and the Antarctic, seabed sediments in four oceans, and tree rings and cave stalagmites around the world have shown us a long natural, moderate global warming/cooling cycle. The Earth warms 2 degrees C or so for 500-800 years, and then cools about the same amount for about the same length of time.
We used to think there was a “solar constant,” but recent satellite measurements of the sun show moderate changes in its irradiance.
Scripps has only a computer model and a set of ocean temperatures going back about 60 years. When I interviewed Barnett, I asked him about the long, natural climate cycle. He said he was “no expert on solar irradiance.” If not, how can he be sure that the warming wasn’t caused by the sun?
The Scripps claims are thin, but they’re bidding for a chunk of a big prize: at least $4 billion per year in government climate research funding.
Where did we ever get the idea that our highly variable weather was the product of a stable climate? The Viking colonies on Greenland, settled during the Medieval Warming, were subsequently cut off from Europe by encroaching sea ice during the Little Ice Age—for 300 years! The inhabitants froze or starved. Archeologists say Andean villages have moved up and down the mountainsides through the centuries as the climate warmed and cooled.
Humans lived through the last Ice Age, when temperatures may have been 25 degrees C colder than at any time recently; and prospered when the Earth warmed by a few degrees.
Can today’s computers command the planets to stand still?
If not, we’d better be prepared to adapt to a natural Modern Warming.
