A False Consensus On Global Warming?
Do all of the world’s climate scientists agree that humanity is causing dangerous global warming?
A California history professor, Naomi Oreskes, says she recently looked at 928 peer-reviewed research studies in a data base on “climate change” and found “none of the papers disagreed with the consensus position” on the Greenhouse Theory.
Normally, getting consensus among scientists is like herding cats. Dr. Oreskes’ finding of complete accord on global warming was so remarkable it was published in Science (Dec. 3) and the Washington Post (Dec. 26).
To cross-check her consensus, I dialed up Google Scholar and plugged in her “climate change” keywords.
I got 213,000 papers on climate change, and flipped through the first 300. Many endorsed the Greenhouse Theory. Especially those from the UN’s Intergovernmental Panel on Climate Change and from climate modelers who get billions of dollars to scare us about CO2.
But not all.
The University of Arizona’s Tom Swetnam had studied fire scars in giant sequoia trees to reconstruct past climate periods. He found a warmer climate in the American Southwest from 1000 to 1300 AD that corresponded with the Medieval Warming in Europe. He also found cool climate periods during the Dark Ages (500 to 1000 AD) and the Little Ice Age (1300-1850). That’s important evidence of climate variability—on America’s Pacific Coast. The North Atlantic is the only region where the UN has admitted these prior climate changes have occurred.
The “climate change” keywords also yielded one of the most famous studies in modern climate science: Gerard Bond’s 2001 Science paper, “Persistent Solar Influence on North Atlantic Climate During the Holocene.” Being a historian, Ms. Oreskes may not have recognized that Bond’s physical evidence of past climate cycles trumps the unproven Greenhouse Theory. In a seabed sediment core, Bond found a series of moderate, natural climate cycles—roughly 1500 years long, plus or minus 500 years. They stretch back hundreds of thousands of years. His 2001 paper confirmed the cycle’s link to variations in the sun’s irradiance, through carbon 14 and beryllium 10 isotopes in the sediments.
Ms. Oreskes should have looked under “climate variability.” Bond and his colleagues don’t think our climate is changing so much as varying naturally, but in roughly predictable ways. There’s been a whole series of Chapman conferences on climate variability, with another proposed this year at the Woods Hole Oceanographic Institute.
Three other papers found under “climate variability”: Switzerland’s Jan Esper and Fritz Schweingruber studied tree line changes in the mountains of Siberia, where the boles of one tree variety are preserved—living and dead— for hundreds of years. They found the treelines around 1000 AD were 30 meters higher than today, indicating the Medieval Warming had higher temperatures than we do. They also found the treelines had receded around the year 1350, at the start of the Little Ice Age, and advanced again with the Modern Warming.
Berger and Von Rad retrieved a 5000-year sediment core from the Arabian Sea—and found the same 1500-year cycle already found by Bond in the North Atlantic. It revealed the unnamed cold period before the Roman Empire, the 1150-year Roman cycle, the 900-year Medieval cycle, and the beginning of the Modern Cycle. Each cycle moves Earth’s temperatures 2 degrees C above and then 2 degrees C below the long-term mean.
J.P. Kennett and a scientific working group on “Climate Variability and Mechanisms” concluded that Earth’s climate in the past 10,000 years “is now known to have been highly unstable and prone to major, rapid changes, especially warmings, that occurred briefly within a few decades or less. . .The scientific community has made major strides in documenting the history of millennial-decadal scale climate change. . .”
There’s no need for scientists to vote on whether the Earth has warmed in the past 150 years. Ms. Oreskes and the UN bureaucrats just need some way to distinguish their Greenhouse Effect from the natural cycle.
Let me suggest one: the Greenhouse Theory says CO2 will first warm the atmosphere above the Earth. The atmosphere will then overheat the planet by radiating heat from above.
So far, the Earth’s surface is warming two or three times faster than the atmosphere. That’s a big Mother Nature vote against the Greenhouse Theory.
