glacial

Sense and Sensitivity

One of the main problems with the “theory” of anthropogenic global warming is its reliance on rising atmospheric CO2 levels to force a global rise in temperature. This is predicted by climate change proponents by running large, complex computer models that imperfectly simulate the physics of Earths biosphere: ocean, land and atmosphere. Central to tuning these general circulation models (GCM) is a parameter called climate sensitivity, a value that purports to capture in a single number the response of global climate to a doubling of atmospheric carbon dioxide. But it has long been known that the Earth system is constantly changing—interactions shifting and factors waxing and waning—so how can a simple linear approximation capture the response of nature? The answer is, it can not, as a new perspective article in the journal Science reports.

Karakoram Rising

Another group of researchers has weighed in on the continuing scientific scuffle over whether the Himalayan glaciers are melting. A letter to Nature Geoscience reports that the Karakoram glaciers, a part of the greater Himalaya north of the actual Himalaya Range, are actually gaining mass. Outside the ice sheets in Greenland and Antarctica, the Karakoram is the most heavily glaciated part of the world, containing nearly 3% of the planet's total ice area. But because they are so large, difficult to get to and dangerous to travel on, they have not been measured by conventional survey methods. Scientists have instead, been relying on satellite measurements, whose accuracy is now called into question. This impressive new study says that the Karakoram glaciers are not only not shrinking, they are accumulating enough ice each year to cause a slight decrease in ocean sea-level.

Rethinking Polar Bear Evolution

A new study in the Proceedings of the National Academy of Sciences (Early Edition on-line), is shaking up science's view of polar bear evolution. Previously, it had been suggested that the white bear of the north was a relatively young species that diverged from brown bears during the last glacial period. That glaciation started after the Eemian epoch (~125,000 years ago), peaking around 25,000 years ago. New genetic analysis pushes that estimated divergence back to 4-5 million years ago, though there seems to have been a significant level of interbreeding between the two species over time. Another important finding is that the polar bear population underwent a significant contraction around 500,000 years ago. According to this new information the polar bear has been around for much longer than previously thought, implying that it has survived many interglacial warm periods. In other words, those who think the polar bear cannot survive the shrinking of Arctic ice packs are dead wrong.

Greenland's Oscillating Glaciers

Melting glaciers are once again in the news, along with the associated threat of rising sea levels. NASA satellites have reported wide spread melting across Greenland which has the climate change alarmists all atwitter. But the NASA satellites are providing data never before available, so it is hard to say if the summer melting pattern is unusual. Meanwhile, some 80 year old scientific data has revealed that this is not the first time that there has been a period of glacial retreat in Greenland. This formerly lost data shows that many land-terminating glaciers underwent a more rapid retreat in the 1930s than in the 2000s. Even more interesting is that the two periods of retreat were interrupted by a period of widespread advance from 1943 to 1972. Greenland's glaciers seem to be oscillating with a period of around a century.

Why Are Sea Levels So Low?

The last interglacial period (LIG)—the Eemian—is commonly believed by scientists to have been warmer than the current Holocene interglacial. Along with that balmier climate there is evidence that sea levels were significantly higher than today. Previous studies have pegged Eemian sea levels at 4 to 6m higher than today. Recently, a new investigation raises that estimate, reporting that ancient sea levels peaked between 6.6 and 9.4 m (~20 to 30 feet). Modern day accounts of flooding in low lying coastal areas and tropical islands abound, with ominous suggestions of links to global warming. How high the oceans will rise is a topic of debate for IPCC members, the news media and assorted climate alarmists, but they are asking the wrong question. Instead, they should ask why are sea levels so low?

The Once & Future Climate?

Between 15 and 20 million years (Myr) ago, Earth's climate took a pause during its long slide into the Pleistocene Ice Age for a period of real global warming. During this relatively brief time glaciers around the world retreated and there are indications that, at least around the edges of the continent, there was significant vegetation on Antarctica. Temperatures may have been as high as 11°C higher than today. Scientists say this global warm spell took place under under CO2 levels in the range of 190–850 ppmv, both significantly higher and lower than today's 390 ppmv. It is hoped that studying conditions during the Miocene warming can provide constraints on the fundamental laws governing the climate system. Why? If the Pleistocene Ice Age is truly coming to an end, as some have said, this may be the climate of the future.

New Climate Models Fall Short

The IPCC is working up to releasing pieces of its next climate report, starting in 2013. This has the world's climate scientists scrambling to get their latest work included in that dubious document. Foremost among those struggling for primacy of place are the computer modelers, those who study their own created worlds instead of the natural one around them. This report promises to be more contentious than the last one (AR4) in that the modelers have been racing to incorporate the effects of aerosols, soot and other airborne particulates that had previously been give scant attention. Early results suggest that aerosols have a much greater impact on regional climate than scientists had realized and that aerosols and clouds are providing some big surprises.

So Insensitive

The dire results of anthropogenic global warming have become passé. Treated by the news media and climate alarmists as established scientific fact, the IPCC's vision of a dystopian future, a world ravaged by global warming, is feed to our children in school, TV shows and Hollywood movies. What is never mentioned is that even the IPCC's predictions encompass several ranges of possible outcome, all predicated on a seemingly simple but mysterious factor called climate system sensitivity. A recent study, published in the journal Science, used spatially more complete paleoclimate data for the Last Glacial Maximum (LGM) in an effort to improve previous estimates of climate sensitivity. The new results have not been widely reported in the news media because, according to the researchers, “these results imply a lower probability of imminent extreme climatic change than previously thought.”

NASA Satellite Debunks Melting Glacier Myth

One of the claims put forth by climate change alarmists is that Earth's glaciers are rapidly melting. This supposedly causes all sorts of problems, from rising sea levels to failing water supplies. A recent report in the journal Nature uses NASA's Gravity Recovery and Climate Experiment (GRACE) satellite to measure the loss of glacial ice around the globe. Analysis of the satellite data on Earth's changing gravity field delivers some unexpected results and the results have surprising implications for both the global contribution of glaciers to sea level and the changes occurring in the mountain regions of Asia.

Arctic Ocean To Close, Polar Bears Doomed

A new theory of supercontinent formation, published in the journal Nature, predicts that the Arctic ocean will be squeezed out of existence in the future as most of Earth's landmass gathers in a new supercontinent—Amasia. The new orthoversion helps to resolve the problems of the older introversion and extroversion models, which have led to a “fundamental disconnection … between the geologic evidence for supercontinent formation, and the models purported to explain their assembly.” If the Arctic Ocean disappears so will the Polar Bear, an iconic species that has been held up as a poster child for global warming. The climate catastrophists are correct in predicting the demise of the white bear of the Arctic, but they have both the reason and time frame terribly wrong.

Ice-shelf Collapse Not Caused By Global Warming

An iceberg the size of Berlin is forming in Antarctica and is expected to break off from the Pine Island Glacier soon. As sure as night follows day, climate change alarmists will pronounce this a result of anthropogenic global warming—and they will be dead wrong. NASA scientists have already predicted the event and proclaimed it a part of a natural, ten year cycle that they have been studying for decades. The sad state of climate science is underlined by the fact that the researchers felt compelled to state that global warming is not the cause of the ice-shelf collapse.

Climate Science's Tangled Web

Recent days have seen a number of announcements about our changing climate. As it turns out Arctic ice is rebounding, sea levels are dropping and things just are not going according to the IPCC's plan for catastrophic global warming. Faced with reversal after reversal, it might seem logical for mainstream climate scientists to admit that they are wrong, that global warming is not taking place at a breakneck pace, but this has not happened. Instead, climate change apologists are weaving a tangled web of excuses—hot is cold, wet is dry, up is down. No matter what happens to the world we live in, the root cause according to the doomsayers is always the same: it's always global warming's fault.

Himalayan Glacier Disappearance Overstated

A pair of researchers has published a new report in the Proceedings of the National Academy of Sciences (PNAS) in which two out of three glaciers studied were disappearing. In a report that was edited by James Hansen, of the Goddard Institute for Space Studies, it would appear that the glaciers of the Himalaya are melting rapidly, but that is not how the report ends. The authors state that poor selection of study sites have led to the widespread use of non-representative data. Moreover, the IPCC report and others overstate the disappearance of Himalayan glaciers.

Climate Models Fail To Predict Past Catastrophes

Most people fall into one of two categories when it comes to predictions of future climate calamities: they either do not realize that the predictions are predicated on computer models or they unquestionably trust the models to reveal the future. A clear and lucid online article in Nature Geoscience addresses the current state and limitations of climate modeling. The article points out that State-of-the-art climate models are largely untested against actual occurrences of abrupt change. “It is a huge leap of faith to assume that simulations of the coming century with these models will provide reliable warning of sudden, catastrophic events,” the author states. To counter claims of predicted “tipping points,” incidents of abrupt climate change from the past are examined—incidents that current models get wrong.

Alaskan Ice

The glaciers of Alaska and northwestern Canada are a major contributor of fresh water to the world's oceans. They have long been considered important contributors to global sea level, but their remoteness has complicated efforts to measure changes in ice mass. As described in a new perspective article, published in the May 27 issue of Science, satellite measurements of Earth's gravitational field and improved on-site measurements have been used to generate global maps of water-mass variation, confirming the large role Alaska glaciers play in global sea-level regulation. Climate change advocates would claim that global warming will melt Alaska's glaciers, flooding low lying countries, but determining the rate at which the glaciers are melting is not a simple thing. Far from solving the puzzle, the new observations are revealing unexpected complexities in the magnitude and rate at which Alaska glaciers respond to climate.

Syndicate content