Dean's World

Is this why humans have relatively little genetic variance compared to most species?

Geneticists Lynn Jorde and Henry Harpending of the University of Utah proposed that the variation in human DNA is minute compared to that of other species. They also propose that during the Late Pleistocene, the human population was reduced to a small number of breeding pairs — no more than 10,000 and possibly as few as 1,000 — resulting in a very small residual gene pool. Various reasons for this hypothetical bottleneck have been postulated, one of those is the Toba catastrophe theory.
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According to the Toba catastrophe theory, 70,000 to 75,000 years ago a supervolcanic event at Lake Toba... The theory was proposed in 1998 by Stanley H. Ambrose of the University of Illinois at Urbana-Champaign.
Within the last three to five million years, after human and other ape lineages diverged from the hominid stem-line, the human line produced a variety of species.
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According to the Toba catastrophe theory, a massive volcanic eruption severely reduced the human population. This may have occurred around 70–75,000 years ago when the Toba caldera in Indonesia underwent an eruption of category 8 (or "mega-colossal") on the Volcanic Explosivity Index. This released energy equivalent to about one gigaton of TNT, which is three thousand times greater than the 1980 eruption of Mount St. Helens. According to Ambrose, this reduced the average global temperature by 5 degrees Celsius for several years and may have triggered an ice age.

When I read theories like this, it always brings to mind the Drake equation and the weak anthropic principle, and makes me wonder just how incredibly unlikely a chain of coincidences we rode on the path to intelligence.

Uh oh.

A new study comparing the composite output of 22 leading global climate models with actual climate data finds that the models do an unsatisfactory job of mimicking climate change in key portions of the atmosphere.
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"The usual discussion is whether the climate model forecasts of Earth's climate 100 years or so into the future are realistic," said the lead author, Dr. David H. Douglass from the University of Rochester. "Here we have something more fundamental: Can the models accurately explain the climate from the recent past? "It seems that the answer is no."

Yeah, that’s a problem. When you're proposing massive global energy taxes to address a problem based on computer models, it's a little inconvenient when they turn out not to work.

Interestingly, the CNS version of the story has much more entertaining quotes than the ScienceDaily piece:

"This means that the greenhouse effect - while real - is not very important in producing climate change," he said. "It's a lot smaller than what the models calculate."

Singer said the reason why the models "overestimate the effectiveness of carbon dioxide and other greenhouse gases is that the models ignore what are called negative feedbacks which occur in the atmosphere, such as clouds, which reduce the effect of the greenhouse gases."

But non-skeptics like Bracken Hendricks are skeptical, and they have irrefutable evidence for their position:

"The Intergovernmental Panel on Climate Change (IPCC) is not just a report. It's not just a random gathering of scientists. It's the largest scientific body ever assembled," he said.

Apparently many scientific studies are "just reports" produced by totally random gatherings of scientists. Good that he clarified that the IPCC report manifesto isn't one of those.

"Their most recent assessment determined that there's 90 percent certainty that global climate change is happening and that it is caused by human beings."

Of course, that also means this massive throbbing nonrandom superbrain of scientists admits there’s a 10% chance that they’re completely wrong and all this time and effort we’re putting into global warming is a gigantic waste of resources.

"We don't want to be gambling with the fate of the planet."

...said the man proposing to gamble trillions on reducing CO2 emissions that may or may not have any positive impact on climate change, based on unreliable computer models that don’t even accurately predict the past.

Who’s ultimately going to be right on the climate science? Hard to say for sure. But Hendricks’ grasp of economic principles doesn’t inspire confidence in his camp:

Hendricks countered, saying that alternative energy will be a multi-billion dollar industry and "an opportunity to revitalize our global competitiveness" through innovation and job creation.

Yeah, and if we pay little kids to break windows, then the glassmakers will have more business, and they will order more from their suppliers, and they’ll order more from their suppliers, and it will create this huge ever-expanding bubble of prosperity… what? What do you mean, broken windows fallacy?

Of course, what will actually happen is that China will chortle and build another thousand cheap CO2-spewing coal-fired power plants, and we’ll be stuck paying higher energy prices, thus further reducing our competitive advantage. But not to worry: we'll lead the world in the lucrative market for inaccurate computer models!