Orbital Ice Age Theory Melts
Orbital cycles do not cause ice ages, a new study suggests. Instead, the whole world experienced an ice age at the same time.
The leading secular theory for past ice ages has taken heat from a new study. According to the theory, orbital cycles called Milankovitch cycles take the earth on excursions nearer and farther from the sun, or on wobbles of tilt, forcing climatic swings. But a study published in Geology calls that theory into question. NASA’s Astrobiology Magazine explains:
The researchers found that glacier movement in the Southern Hemisphere is influenced primarily by sea surface temperature and atmospheric carbon dioxide rather than changes in the Earth’s orbit, which are thought to drive the advance and retreat of ice sheets in the Northern Hemisphere….
The study raises questions about the Milankovitch theory of climate, which says the expansion and contraction of Northern Hemisphere continental ice sheets are influenced by cyclic fluctuations in solar radiation intensity due to wobbles in the Earth’s orbit; those orbital fluctuations should have an opposite effect on Southern Hemisphere glaciers.
Geologists from Dartmouth looked at Beryllium-10 data in New Zealand glaciers and found that past glaciers were as large as those in the northern hemisphere. This contradicts the Milankovitch theory:
This makes sense in that the whole world was cold at the same time, but the Milankovitch theory should have opposite effects for the Northern and Southern Hemispheres, and thus cannot explain the synchronous advance of glaciers around the globe. Previous studies have shown that Chilean glaciers in the southern Andes also have been large at the same time as Northern Hemisphere ice sheets.
This loss of confidence in the Milankovitch theory has implications for current debates about climate change:
“Records of past climatic changes are the only reason scientists are able to predict how the world will change in the future due to warming. The more we understand about the cause of large climatic changes and how the cooling or warming signals travel around the world, the better we can predict and adapt to future changes,” says lead author Alice Doughty, a glacial geologist at Dartmouth College who studies New Zealand mountain glaciers to understand what causes large-scale global climatic change such as ice ages.
Conversely, by implication, the less they understand about the causes of large climate changes, the less they can predict future warming.
Biblical geologists point to the aftermath of the Genesis flood as the explanation for a single Ice Age, not many. They point to rise in sea level temperatures causing massive snowfalls – in fact, the only mechanism able to increase precipitation adequately (counter-intuitively, it requires warm seas to increase snowfall). Milankovitch cycles are too weak, they say, to account for climate change; instead, the release of internal heat from the “fountains of the great deep” (Genesis 7:11) brought about warmer seas that caused rapid, massive dumps of ice and snow for years afterward. Flood models also allows for advance and retreat of glaciers for centuries after the flood, as the earth re-adjusted to the rapid crustal changes that occurred during the breakup of the continents.
See also “Breaking up an ice age is hard to do” (7/01/10) and “Milankovitch cycles indistinguishable from randomness” (6/02/09).
This is important, because the Milankovitch theory has taken on the air of “accepted truth” by uniformitarian geologists. Creation geologists should take a close look at this new study and advertise the demise of “orbital forcing” ideas in favor of the only theory that has a documented historical foundation: the Genesis flood. The story also serves as a warning to those Christians too eager to harness their theories to the consensus views of secular scientists.
The language of the article is a bit confusing: do they mean ‘cyclic’ rather than ‘opposite’ effects? And even given the naturalistic nature of the ice ages, do they actually believe they can detect SEASONAL changes in a (supposed) mega-year record? Now, THAT’s ego for you!