The Appalachian mountains are seldom mentioned among the world's great mountain ranges. Consisting mostly of low gentle ridges, when compared with the snow-capped peaks of the Himalaya, Andes, or Alps many would hesitate to call them mountains at all. But they are a large and ancient range, stretching over 1500 miles along the eastern portion of North America. The time of their formation has been dated back to the Paleozoic, with major uprisings occurring 650 million years ago. Then, about 460 million years ago, during the Ordovician period, they were the site of one of the most violent volcanic outbursts in Earth's history. New research reveals that, following that bout of vulcanism, weathering of Appalachian rock may have triggered one of Earth's major ice ages—a relatively brief frigid period that ultimately killed two-thirds of all species on the planet.
A new study has confirmed the astronomical theory of the ice ages, but with a new twist: The shutoff of the meridional ocean circulation, or MOC, and an associated southward shift of tropical monsoon rain belts seems to play an integral role in the melting of glacial period ice sheets. These changes cause warming of the Southern Hemisphere and a rise in atmospheric CO2 levels, which in turn provides a positive feedback loop that helps drive glacial termination. This is why, every 100,000 years or so, the great Northern Hemisphere ice sheets collapse and glacial conditions give way to a warm interglacial period, such as the Holocene warming humanity is currently enjoying. This, however, does not support recent claims that global warming is causing the Southeast Asian monsoon to fail.
Despite recent attempts to revive the discredited “hockey stick” temperature graph, invented by Michael Mann and promulgated by the IPCC, new research on tropical glaciers has once again shown that supposed temperature history to be bogus. While the role of the tropics in climate change remains an open debate in climatology circles, new data suggests linkages between the tropics and the North Atlantic region. In particular, prominent glacial events and associated climatic shifts in the outer tropics during the early Holocene and late in the “Little Ice Age” period indicate that the LIA was indeed a global event.
The search for ways to reduce carbon emissions has led to government grant money for schemes ranging from promising to wacky. Recognizing that there is no currently viable replacement for fossil fuels, with the possible exception of nuclear power, the US and other countries with large coal deposits are desperately looking for ways to continue burning coal without incurring the wrath of nature or the IPCC. Clear evidence of the seriousness of this effort is evident in this week's special edition of Science, dedicated to carbon capture and sequestration (CCS) technology.
Contrary to what is said in the popular media, water (H2O) is the most important greenhouse gas in Earth's atmosphere, not the small amount of demonized CO2. But aside from acting as a greenhouse gas, water vapor plays an active role in shaping global atmospheric circulation and thus Earth's climate. Water does this by undergoing state changes—from liquid to vapor and back again—allowing water vapor to carry significant amounts of latent heat from the warm equatorial regions toward the poles. The importance of this heat transfer mechanism in climate regulation is poorly understood but new data have begun to show the impact is major. One thing is certain, most widely used climate models do not correctly account for the complex dynamics of water vapor.
The supporters of anthropogenic global warming (AGW) claim that they have science on their side. Time and again we are told that the debate is over, the science is settled and consensus among the world's scientists reached. If that is true, why are so many scientists coming forward to oppose and denounce the climate alarmist's theory? To understand the true nature of the climate change debate it is necessary to understand what a scientific theory is and how to judge a theory's validity.
Two of the terms bandied about by global warming alarmists are “unprecedented” and “irreversible.” It is troubling that scientists, who should know better, persist in using these terms even though the history of our planet clearly shows that neither term is accurate. Proof of this inaccuracy is obvious if we look back over the history of Earth—the Phanerozoic Eon in particular—taking the “Grand View” of historical climate change.
Not satisfied with blaming modern civilization for causing rampant climate change, now a small group of scientists are saying that everything went wrong once humans stopped being hunter-gatherers 9,000 years ago. The hypothesis, first advanced in 2003 by University of Virginia palaeoclimatologist William F. Ruddiman, remains controversial even among global warming true believers. Ruddiman now claims to have proven his critics wrong, much to the glee of the blame-humanity-first wing of the eco-activist community.
While the IPCC and global warming alarmists continue to claim climate change is controlled by atmospheric CO2 levels, most knowledgeable scientists will tell you that climate change is caused by variation in Earth's orbit and orientation. These periodic changes in movement and attitude are called the Milankovitch Cycles. A new paper, to be published in Science, confirms that glacial terminations are caused by Earth's orbital cycles, not carbon dioxide.
Chad, located along the southern edge of the Sahara Desert, is the dustiest place on Earth. Recognizing that aerosols plays a vital role in climate and biophysical feedback in Earth's environmental system, climate researchers are turning to dust as a major driver of climate change. A new article, to be published in PNAS, identifies the Bodélé Depression in Chad as the producer of about half the mineral aerosols emitted from the Sahara. According to Richard Washington et al. dust could be a “tipping element” where “small features of the atmospheric circulation, such as the Bodélé Low-Level Jet, could profoundly alter the behavior of this feature.” With the impact of CO2 diminished due to a cooling climate climate, researchers are searching for new hazards: Is African dust the new carbon dioxide?
Increased insolation 20,000 years ago caused deglaciation in the Northern Hemisphere, according to a new report in the August 7, 2009, edition of Science. Further more, it was the onset of deglaciation of the West Antarctic Ice Sheet, which occurred between 14 - 15 thousand years ago, that was the source of sea-level rise at the beginning of the Holocene warming. Such events are often associated with rising CO2 levels by climate catastrophists but the evidence says otherwise.
Bleached and dying coral reefs are often held up as proof that global warming is laying waste to Earth's ecosystems. Now come reports that a number of reefs around the world are being brought back from the dead by dedicated oceanographers and conservationists. “The results are more than just promising; they are beautiful,” says Baruch Rinkevich, a marine biologist at the National Institute of Oceanography in Haifa, Israel. But how can these reefs recover in the face on ongoing global warming? Either global warming has reversed course or the bleaching of reefs wasn't due to global warming in the first place.
We have all heard the litany of woes about to befall mankind due to global warming: failing crops, spreading deserts, increased storm activity, rampant disease, and so forth. But these are not the most frightening side effects of global warming. Indeed, the IPCC's list only scratches the surface of the prophecies of doom and despair. Among the predicted results of a warming climate are smaller livestock, an increase in kidney stones, more frequent bear attacks and a host of other maladies and misfortunes.
Two articles in the July 17 edition of Science describe efforts to model Earth's rapidly changing climate at the end of the last glacial period, between 21 and 11 thousand years years ago (ka). After a year and a half of number crunching on Oak Ridge National Laboratory's Jaguar supercomputer, the first results indicate that climate experienced cooling 17 ka, during the Heinrich Event 1 (H1), followed by an abrupt warming at the onset of the Bølling-Allerød Warming 14.5 ka. These abrupt climate changes were accompanied by large changes in the “ocean conveyor belt”: the Atlantic meridional overturning circulation (AMOC). The results suggest that this transition can be viewed simply as the North Atlantic climate response to rapidly changing glacial meltwater flow. The findings call for a paradigm shift in our understanding of abrupt climate change and weakens the threat of “irreversible tipping points” so popular with climate change extremists.
Having reported that scientists did not find CO2 responsible for a change in the duration of ice age glacial periods 700,00 years ago, another new report takes a look at the conditions around the last interglacial warm period and our own Holocene warming. Using corals from the south seas paradise of Tahiti to track sea-level changes, researchers probed the mechanisms driving Earth's climate between glacial and interglacial states. Almost as an after thought they added that there is no longer any doubt: changes in sea-level drive changes in CO2, not the other way around.