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.
Using satellite infrared spectroscopy to provide an almost global perspective on the near-surface distribution of water vapor, a new report in Science has identified more water vapor inaccuracies in current general circulation models (GCM), the computer programs used by climate scientists to predict future climate trends. The researchers uncovered anomalies in the Hadley circulation and its misrepresentation in GCM. Looks like climate theory and the IPCC's error ridden models are in for another round of corrections.
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.
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.
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.
In a stunning paper in Science, researchers claim to have reversed the impact of clouds on global climate. It has long been known that low level cloud cover creates a net cooling effect on climate. This new study, which concentrated on a restricted area of the Pacific Ocean, claims that warming oceans reduce low cloud cover letting in more sunlight that further warm the ocean and hence provide a positive feed back that adds to global warming. Based on a warming episode that started in 1978, the article claims that observational analysis showed that clouds act as a positive feedback in this region on decadal time scales. But a cometary on the article in the same issue of Science says that the analysis suggests—but falls short of proving—that clouds are strongly amplifying the warming. If it's true, then almost all climate models have got it wrong.
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.
A new paper in Science reports that a careful study of satellite data show the assumed cooling effect of aerosols in the atmosphere to be significantly less than previously estimated. Unfortunately, the assumed greater cooling has been used in climate models for years. In such models, the global-mean warming is determined by the balance of the radiative forcings—warming by greenhouse gases balanced against cooling by aerosols. Since a greater cooling effect has been used in climate models, the result has been to credit CO2 with a larger warming effect than it really has.
A new paper by a group of “sustainability scientists” has called for an end to “business as usual” in efforts to curb CO2 emissions. The authors advocate allocating CO2 emissions targets based on the ‘‘common but differentiated responsibilities’’ of individuals, rather than nations. Their proposal moves beyond per capita considerations to identify the world’s high-emitting individuals, regardless of the country they live in. Don't laugh—if you are reading this post on the Internet you are probably one of the targeted billion.
When it comes to climate, the early Paleogene period (~65-34 mya), at the start of the Cenozoic Era, had one of the most Eden like climates of the Phanerozoic Eon. As the Cenozoic progressed a cooling trend set in leading up to the formation of permanent ice caps and the Pleistocene Ice Age we are still experiencing. But before the world started to ice up our planet underwent one of the most dramatic bouts of global warming known to science—the Paleocene Eocene Thermal Maximum or PETM. Recently, global warming activists have tried to liken human CO2 emissions to the cause of the PETM, 55 million years ago. Is it true, that our actions may trigger a sudden sharp rise in global temperature?
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.