Earth's climate has shifted drastically many times in its history, but barring massive asteroid impacts, climate change tends to play out over thousands or tens of thousands of years. Plenty of time to pack away the summer clothes and buy a nice warm coat when you spot an ice age coming. But researchers at the University of Saskatchewan recently discovered that some ice ages come on quite rapidly.

By taking some very thin slices of a mud core sampled from a really old lake (Ireland's Lough Monreach), the Saskatchewan team got a high-resolution look at varying oxygen and carbon isotope levels in the lake's history. The analysis revealed events happening month by month in the lake's ancient past. They found that things got very cold very quickly during the "Big Freeze" (more scientifically referred to as the Younger Dryas), a small ice age that occurred about 13,000 years ago. How quickly? The lake basically froze solid within a few years, and it might even have happened within a few months.

The Younger Dryas is thought to have been caused by the sudden emptying of Lake Aggasiz, a massive freshwater sea that covered a much of what is now mid-Canada and the northern U.S. At some point, the contents of the lake poured down through the Great Lakes and down the St. Lawrence River, flooding the Arctic Ocean and the North Atlantic with a deluge of fresh water. Not only did this raise global sea levels, it severely disrupted ocean currents in the area, scrambling the climate and causing an instant ice age. It took about 200 years for things to get back to normal.

Since there's no Lake Aggasiz around to empty itself and cause an ice age, we're off the hook, right? Wrong. The Greenland Ice Sheet (which is an enormous slab of ice that covers most of Greenland) has been melting at a rate of about 50 cubic miles of ice per year. Because the ice sheet basically keeps itself cold, scientists worry that the growing melt zones each summer will lead to a runaway meltdown. If the sheet were to melt away suddenly, it could very well lead to a disruption of ocean currents similar to the one preceeding the Younger Dryas.

Of course, that would probably be the least of our problems, since sea level would rise more than 20 feet. And you still can't outrun cold.

Big Freeze Plunged Europe Into Ice Age in Months. [Science Daily]

Climate researchers at the University of Edinburgh have been creating models to predict the path of future climate events. In studying past ice ages, they have found that the ice ages have been lasting longer, and that the temperature extremes between the ice ages have become more pronounced. They predict that, without human intervention, the next ice age could have been the most profound in recent geological history, lasting more than a hundred thousand years. Global warming, however, may have postponed that super ice age indefinitely:

"Climate skeptics could look at this and say, CO2 is good for us," said study leader Thomas Crowley of the University of Edinburgh in Scotland.

But the idea that global warming may be staving off an ice age is "not cause for relaxing, because we're actually moving into a highly unusual climate state," Crowley added.

The challenge for climate scientists now is that the future climate will be extraordinarily difficult to predict, as the unnatural increase in carbon dioxide has left researchers with no model on which to base their predictions.

[National Geographic]

The main character, Alexander, has been traveling forward in time from the 19th. century, assuming that humanity will keep becoming more scientifically advanced. He needs to find someone who can unravel the temporal paradox he's caught himself in, so he can save his girlfriend from being crushed back in 1899. But after the moon-blasting incident, he slowly realizes that humanity never gets any more tech-savvy. He's actually the most advanced scientific mind in human history, because we destroyed ourselves before we got any further. Okay, he does finally meet a Morlock in 802,371 who explains the movie's plot to him. But he's the greatest technological mind in history. Sucks to be him.

The other great thing about the otherwise awful Time Machine remake is the sassy holographic library computer Alexander meets in 2030, who keeps popping up throughout the movie. At one point, the movie gets all metatextual and the library hologram tells Alexander about the book The Time Machine, which was made into two movies and a Broadway musical. And then the hologram splits into four holograms and sings a selection from the musical's score.

And then, sadly, the movie dives into a vortex of suck, from which it never emerges. Weirdly, the worst parts of the movie are the only parts where it tries to be faithful to the original book, including the Morlocks/Eloi segments. It makes you wish Wells had just made an original movie, instead of trying to base on great-granddad's book.