Once again the fear-mongering hoards of lay-climatologists are denouncing the importance of the Medieval Warm Period (MWP), or Medieval Climate Optimum as some refer to it. On the strength of a single new study, involving algal lipids from a lake in Svalbard, Norway, one pundit referred to the “so-called” Medieval Warm Period and impugned the significance of the Little Ice Age for good measure. Of course the writer, an “ecological journalist,” saw nothing wrong with using such a dismissive and pejorative term since it is IPCC promoted doctrine that today things are warmer than they have ever been since the onset of the Holocene. Yet literally hundreds of other studies have shown that the MWP was as warm or warmer than today and that is the real consensus among paleoclimatologists.
Over the past 50 years or so, the Antarctic Peninsula, the northernmost part of the mainland of Antarctica, has experienced rapid warming and the collapse of a number of ice shelves. A new temperature record derived from an ice core drilled on James Ross Island, has triggered a reassessment of what triggered the recent warming trends. This new core provides the best record of climate events on the peninsula going back at least 20,000 years, and may extend back as far as 50,000 years. From this new data a team of researchers has constructed the most detailed history of climate on the Antarctic Peninsula known to science and it has revealed a number of interesting things. Most important of these is the fact that this area undergoes bouts of rapid warming periodically and that things were at least as warm on the peninsula 2,000 years ago. So much for “unprecedented” warming on the Antarctic Peninsula.
That large changes in solar radiation can affect Earth's climate is widely accepted. However, the hypothesis of solar-induced centennial to decadal climate changes, which suggests feedback mechanisms in the climate system amplifying even small solar variations, has not found acceptance among orthodox climate scientists. The climate change clique would rather place their money on greenhouse gasses—human generated CO2 in particular. It is true that satellite-based measurements of total solar irradiance show that mean variations during solar cycles do not exceed 0.2 W m−2 (~ 0.1% of the Sun's energy output). It has also been noted that relatively large variations of 5–8% in the ultraviolet (UV) frequencies can occur, though how this could change global climate remained a puzzlement—but perhaps no longer. From studying a significant climate shift 2,800 years ago, a group of scientists have concluded that large changes in solar UV radiation can, indeed, affect climate by inducing atmospheric changes.
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?
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.
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.
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.
Many of the more strident reports regarding runaway global warming center on rapid ice loss from the glaciers of Greenland. During the early 2000s the Greenland Ice Sheet experienced the largest ice-mass loss since accurate instrument readings have been kept. This was largely caused by the acceleration, thinning and retreat of large outlet glaciers in West and southeast Greenland. Now a new study in Nature Geoscience confirms that ice loss from the Helheim Glacier between 2003 and 2005 was the worst recorded—at least since the last period of rapid ice loss during the late 1930s.
In 2009, the International Commission on Stratigraphy, the body charged with formally designating geological time periods, decided the Anthropocene concept “has some merit.” To investigate further they formed the Anthropocene Working Group, which published their initial findings this past February in a special issue of the Philosophical Transactions of the Royal Society A. The group reported a wide range of human impacts that could leave a stratigraphically significant mark on the planet's geological record. There is no doubt that humans have changed the world we live in, but has the change been significant enough to declare a whole new epoch? The Anthropocene debate is continuing this week at the 2011 Geological Society of America conference.
No phenomenon in astronomy has been studied more closely than solar flares, gigantic eruptions on the Sun that can affect Earth's climate and even disrupt power grids. Scientists have been watching the Sun with ground based instruments and orbiting satellites for years, so it might be thought that we know a lot about such eruptions. Well think again. A new report from NASA has revealed that, like earthquakes, solar flares often have aftershocks. Moreover, the aftershocks can emit bursts of ultraviolet (UV) radiation more powerful than the original eruption. Combine this new finding with the recently uncovered linkage between fluctuating UV levels and El Niño, and the Sun-Climate connection looks stronger than ever.
Tracking the flow of ice in the Arctic is difficult. Reconstructing the extent and flow in times past is even more difficult. An interesting new report has turned to driftwood, embedded in the Arctic pack ice, as a way of deciphering Arctic climate conditions over the last 10,000 years. The researchers found a climate record that is in good agreement with previous histories, including such events as the Medieval Warm Period, the Little Ice Age and the Holocene Thermal Maximum. In fact, they found temperatures during the HTM to be 2° to 4°C higher than today. They also found a complementarity oscillation in sea-ice abundance between East and West that is not correctly simulated by current ice models.
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.
Much fanfare was associated with the reappearance of sunspots earlier this year, marking the beginning of a new period of high solar activity. Now come a number of reports saying the Sun is most likely headed for a prolonged period of low activity, possibly rivaling the Maunder minimum. Three independent studies of the Sun's dynamics all predict that the next solar cycle will be significantly delayed and might even be skipped. The Maunder minimum is associated with a prolonged period of climate cooling known as the Little Ice Age. Whether Earth's climate is headed for a significant cooling trend has become a matter of heated debate, while at the same time NASA is warning that a quite Sun can also be a deadly Sun. In the 1850s, following a period of low sunspot activity, the largest coronal ejection event ever witnessed caused havoc with telegraphs and ship's compasses around the world. Such an ejection today could cause widespread power outages and failure of electronic equipment. Will our star turn both quiet and deadly?
It is well known that water, H2O, is the single most important greenhouse gas. But water also plays a central role in determining the delicate balance of energy and mass that regulates the temperature of Earth. A wide range of predictions have been made regarding water in a warming climate, ranging from catastrophic droughts to increased monsoon rains and tropical storms. Conventional wisdom states that a warmer world is a wetter world. In a newly published paper in the journal Science, two researchers examine the Eocene (∼56 to 34 million years ago), looking for clues to the tropical climate–water relationship. Annual global temperatures during the Early Eocene Climatic Optimum (EECO) around 50 million years ago were as much as 12°C higher than modern values. The new results provide compelling evidence that the tropical engine of the water cycle was more active than predicted by current climate models.
Beginning in 2008, sunspots almost completely disappeared for two years. Solar activity dropped to hundred-year lows and the Sun’s magnetic field weakened, allowing cosmic rays to penetrate the Solar System in record numbers. More troubling, Earth's upper atmosphere cooled and collapsed by an unprecedented amount. Solar physicists openly wondered what was happening to our neighborhood star. Now, an international team of scientists funded by NASA claims to have figured out what was going on. Their explanation was just published in the March 3, 2011, edition of Nature.