One of the scary scenarios frequently trotted out by climate change alarmists is the possible shutdown of the ocean currents in the Atlantic Ocean. This would disrupt northern hemisphere climate, particularly in Europe. Indeed, one Hollywood disaster movie had frozen military helicopters falling from the skies in the UK and Manhattan buried under a tsunami of ice. We are told this could happen at any time, if the world gets too hot from all that CO2 our species is churning out. Now a shocking new paper in the journal Science implies that the standard view of a relatively stable interglacial circulation may not hold for conditions warmer/fresher than at present. Why? Because it happened before, over 100,000 years ago, without the help of man made global warming. Another catastrophic climate threat is shown to be totally natural and to have happened before our species began burning coal and driving SUVs.
Climate change alarmists point to the past several decades of European weather to reinforce their claim that global warming has the continent in its grip. A new report shows that this recent warm spell is nothing abnormal or unprecedented—during the 1990s there was simply a return to conditions present during 1931-1960. The reason for the shift is warm ocean temperatures that are, in turn driven by variation in warm ocean currents from the tropics. The instrumental record shows that, relative to the average temperature of the rest of the world’s oceans, the temperature of the North Atlantic Ocean has fluctuated between anomalously warm and anomalously cool phases, each lasting several decades at a time. Palaeoclimate records suggest that similar variations extend much farther back in time. The observed pattern of multidecadal variation in North Atlantic sea surface temperatures (SSTs) has become known as the Atlantic Multidecadal Oscillation (AMO).
The climate associated with global oceans undergoes natural variability with many time scales. A recent report in the Journal Science identifies atmospheric blocking over the North Atlantic as a major factor in such variability on time scales as short as a week. The correspondence between blocked westerly winds and warm ocean can be seen in recent decadal episodes, particularly from 1996 to 2010. It also describes much longer time scale Atlantic multidecadal ocean variability (AMV), including the extreme northern warming of the 1930s to 1960s, which predates the rise of human CO2 emissions that alarmists are convinced is causing all recent global warming.
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.
Around 19,000 years ago, oceanic conditions underwent dramatic changes that coincided with a shift in global climate, marking the onset of the Holocene warming. In the North Atlantic, major changes in the Meridional Overturning Circulation (MOC), which carries warm and highly saline surface water north to cooler regions, played a substantial role in regulating climate and levels of atmospheric carbon dioxide. Scientists are now convinced that the ocean absorbed, stored, and released vast quantities of carbon in the past, playing a major role in the end of the last Pleistocene Ice Age glacial period. Understanding the ocean's role in the past is important to understanding how it may influence climate in the future. A new report in Science shows that the MOC experienced a series of abrupt changes that lasted from decades to centuries, and may have stored and released more CO2 than previously thought.
Time after time, the public has been harangued by climate change “experts” predicting all form of devastation due to anthropogenic global warming. The Greenland and Antarctic glaciers will melt, as will the sea ice covering the Arctic Ocean. Temperatures will rise by 2-6°C, perhaps more in higher latitudes. Weather patterns will shift, there will be droughts and torrential monsoon rains, cyclones will increase in intensity—where will it all end? Here's a thought, we might find the world a nicer place after a bit of global warming. In fact, given the general cooling trend seen over the Holocene (the period since the last glacial period ended around 14,000 years ago) and the Cenozoic (the time since the dinosaurs died, around 65 million years ago) human CO2 may be, in some small way, the only thing delaying another devastating ice age.
After nearly 50 years of acceptance, the theory that a great ocean “conveyor belt” continuously circulates water around the globe in an orderly fashion has been dismissed by a leading oceanographer. According to a review article in the journal Science, a number of studies conducted over the past few years have challenged this paradigm. Oceanographers have discovered the vital role of ocean eddy currents and the wind in establishing the structure and variability of the ocean’s overturning. In light of these new discoveries, the demise of the conveyor belt model has been become the new majority opinion among the world's oceanographers. According to M. Susan Lozier, of Duke University, “the conveyor-belt model no longer serves the community well.”
Climate scientists have decided that as much as half of the heat energy, believed to have built up on Earth in recent years, is hiding somewhere it can not be found. By measuring the radiative energy input at the top of Earth's atmosphere, scientists have a pretty good idea of how much energy is entering the planetary environment—the problem is figuring out where it goes. The most likely place is in the deep ocean, whose waters form a huge potential storage place for heat. Because energy is exchanged between the atmosphere and the ocean, this heat can resurface at a later time to affect weather and climate on a global scale. It has been suggest that last year’s rapidly occurring El Niño may be one way the “missing” solar energy has reappeared—the implication being more sudden El Niño events may be on the way.
The Atlantic Meridional Overturning Circulation (AMOC), also known as the “Ocean Conveyor Belt,” has been the subject of much study since its discovery. The AMOC is primarily responsible for Europe's temperate climate and some scientists have warned that global warming could cause the ocean's flow to slow down or even stop. This rather counter intuitive result of a warming climate would result in a much colder Europe—perhaps even a new mini-ice age. A new analysis of data from satellites and drifting sensors finds no evidence that the conveyor belt is slowing. In fact, a NASA backed study indicates that the conveyor is far less susceptible to throttling by climate change than some climate change alarmists feared.
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.
According to State of the Climate in 2008, a special supplement to the August, 2009, issue of the Bulletin of the American Meteorological Society, greenhouse warming has been stopped in its tracks for the past 10 years. The HadCRUT3 temperature record shows the world warmed by only 0.07°C (±0.07°C) from 1999-2008. The UN's Intergovernmental Panel on Climate Change, who have led the global warming disaster circus for the past two decades, had predicted 0.20°C. Just a temporary setback claim the true believers, global warming will be back with a vengeance. Add a mad scientist's cackling laugh and you have a story fit for a comic book villain.
News has come that the famed ocean conveyor belt, subject of countless TV documentaries and science lessons, is not as simple as scientists believed. The 50 year old model of global ocean circulation that predicts a deep Atlantic counter current below the Gulf Stream has been called into question by an armada of drifting subsurface sensors. As shocking as this news is to oceanographers it is even worse for climate modelers—it means that all the current climate prediction models are significantly wrong.
The current hot phrase bandied about by talking heads and parotted by news pundits is “tipping point.” We are told that the climate may be near a tipping point, if it has not crossed one already, and that can't be good. But what is a tipping point, where do they come from and how can we identify one when we see it?
Eclipsed by the pageantry of the 2008 Beijing Olympics and Russian attempts to start WWIII by invading their former client states, is a noticeable downward trend in global temperatures. Data from the UK Meteorology Office shows that temperatures in the first half of the year have been cooler than any year since 2000. The reason given for the cooler temperatures is the natural cycle of La Nina and El Nino periods, which affect climate world wide.