Earth's climate history includes numerous incidents of rapid warming and cooling. While Pleistocene ice-age glacial terminations are arguably the most dramatic recent examples of sudden climate change, during the last glacial period the climate of the Northern Hemisphere experienced several other significant episodes when the climate rapidly warmed. Scientists call these episodes Dansgaard-Oeschger (DO) events after the Danish and Swiss researchers who documented them using ice-core studies. These rapid oscillations are marked by rapid warming, followed by slower cooling. The most prominent coolings are associated with massive iceberg discharge into the North Atlantic Ocean known as Heinrich events (HE). The melting icebergs add large volumes of cold fresh water to the ocean, disrupting circulation patterns and causing further climate changes. Scientists look to past events like these to help us understand how Earth's climate system functions—what causes our planet to cool or suddenly warm. Recently, new data on past climate changes have led one commentator to predict the end of winter skiing in the American Southwest.
The golden toad of Costa Rica was declared extinct in 1994, five years after it was last sighted in the wild. The unfortunate toad's was the first extinction to be blamed on anthropogenic global warming and it has often been cited as an example of things to come if mankind doesn't change its CO2 spewing ways. But humanity's conviction of toadacide was premature and based on circumstantial evidence. After years of study scientists have a new finding: humans were not at fault after all.
Around 1.2 million years ago, only 18,500 early humans were breeding on the planet. According to researchers, this is evidence that there was a real risk of extinction for our early ancestors. What's more, according to a new study it took at least a million years for humans to come back from the brink. It was not until the emergence of modern humans, Homo sapiens, around 160,000 years ago and their migration out of Africa that humanity's place on Earth was secured. Two factors helped humans to survive: an increasingly carnivorous diet and mastery of fire.
The debate over anthropogenic global warming—a theory propounded by the UN IPCC—is often portrayed as an argument between deniers and true believers. The deniers supposedly claim that there is no global warming, man made or otherwise, and that the whole theory is a plot by left-wing agitators and closet socialists bent on world domination. The true believers, conversely, accept every claim of pending future disaster uttered by scientists and activists alike. As with most controversies both extreme positions are wrong and the truth lies somewhere in-between. As a scientist, I have studied the evidence and find the case for imminent, dangerous, human caused global warming unconvincing—here is why I am an AGW skeptic.
With all the predictions of short term climate catastrophes proffered by global warming alarmists it is hard to look forward to a future time on Earth. What does the future hold a thousand, ten thousand, a million years from now? Science has some predictions about that as well, though the news media have not picked up on them. What environmental changes await us on the long road ahead?
One well accepted definition of the “Three Pillars of Science” lists the three as theory, experimentation and computation. For climate science this translates into climate theory, gathering climate data, and climate modeling. The three pillars are due an update in this post Copenhagen, post Climategate world. After reviewing the past year's crop of discoveries and disclosures, it seems that all three pillars are still wobbly at best—even without questionable conduct on the part of warm-mongering researchers.
There have been a number of strange theories regarding the conditions deep within Earth's interior circulating around the internet. Claims that solar flares will cause nuclear reactions deep below our feet are perhaps the most ludicrous, but fairly easy to dismiss. More timely, perhaps, is the sudden conversion of global warming guru Al Gore into a geothermal energy booster. Evidently Gore thinks it's bad to drill for oil, but good to drill for heat. TV documentaries threaten mega-volcano eruptions and talk about mantle plumes underneath Hawaii, but just what does science tell us about our planet's interior?
A number of recent papers analyzing the nature of climate models have yielded a stunning result little known outside of mathematical circles—climate models like the ones relied on by the IPCC contain “irreducible imprecision.” According to one researcher, all interesting solutions for atmospheric and oceanic simulation (AOS) models are chaotic, hence almost certainly structurally unstable. Further more, this instability is an intrinsic mathematical property of the models which can not be eliminated. Analysis suggests that models should only be used to study processes and phenomena, not for precise comparisons with nature.
In an essay adapted from his 2009 AAAS Annual Meeting keynote address, James J. McCarthy has produced a fairly concise statement of the anthropogenic global warming believer's world view. After a self-serving review of climate science history, McCarthy trots out the usual litany of climate change troubles: increased cyclones, rain and floods, rising sea levels and, of course, those pesky tipping points. The tone of the article is set early on, when research is cited stating that mankind's impact on Earth is “sufficiently profound to declare that we have transitioned from the Holocene era of Earth history to the Anthropocene.”
While climate skeptics have gleefully pointed to the past decade's lack of temperature rise as proof that global warming is not happening as predicted, climate change activists have claimed that this is just “cherry picking” the data. They point to their complex and error prone general circulation models that, after significant re-factoring, are now predicting a stretch of stable temperatures followed by a resurgent global warming onslaught. In a recent paper, a new type of model, based on a test for structural breaks in surface temperature time series, is used to investigate two common claims about global warming. This statistical model predicts no temperature rise until 2050 but the more interesting prediction is what happens between 2050 and 2100.
Twenty thousand years ago, North America had a more impressive array of big animals than Africa does today. The continent was populated by mastodon, several species of mammoth, giant ground sloths, saber-toothed cats and bison twice the size of their modern counterparts. By 10,000 years ago most of these animals were gone, including the 10 species that weighed more than a ton. Many drastic changes occurred during this interval, including the arrival of Homo sapiens to the new world. Many have cited humans as the cause of this great megafaunal die-off: were H. sapiens causing mass extinctions even during the stone age?
Climate and environmental scientists have become dependent on computer models in recent decades. The scientific literature and the popular press are filled with strident warnings of impending natural disasters, all predicated on the output of computer programs. The IPCC has solemnly predicted that climate change will drive thousands of species to extinction if anthropogenic global warming is not reined in. The coprophagous press has uncritically swallowed these computer generated droppings, reporting conjecture as fact and possibilities as certainties. Even though the climate change faithful continue to blindly believe the IPCC predictions, at least some researchers are aware of the glaring flaws in their computer models.
There are a number of scientists who disbelive the theory that an asteroid impact killed the dinosaurs. They point to evidence that some species of sauropod may have survived the Chicxulub impact—widely hailed as the smoking gun in the dinosaur extinction—as proof that the event was simply not big enough to be a knockout blow. Now, according to Sankar Chatterjee of Texas Tech University, new information reinforces his claim that a much larger impact that he has named Shiva, actually did the dinosaurs in.
Tropical America is one of many regions that have seen significant losses of amphibian species over the past few decades. In 2004, the first global assessment of amphibians revealed that almost a third of the world's known species are threatened with extinction. Early on, experts linked the mysterious disappearance of frog species throughout Central and South America to a fungal disease that was supposedly exacerbated by global warming. Now, according to new discoveries, it looks like climate change isn't to blame after all.
A report out from the United Nations Framework Convention on Climate Change meeting, which was held in Barcelona, identifies peaty wetlands as a major source of CO2. Marshes, swamps and bogs emit about 1.3 billion tonnes of CO2 a year as a result of human activity that drains them. If those dried out former swamps catch fire that amount can double and large amounts of aerosols can be emitted as well. With governments offering subsidies for growing biofuel crops the question is, how do we stop people from draining the world's remaining wetlands?