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.
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.
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.
In the debate over climate change one of the most misunderstood and misused terms is sensitivity. Climate sensitivity is usually defined as the change in global mean surface temperature following a doubling of atmospheric CO2 once equilibrium is reached. The concept seems simple but there is a catch: the definition of 'equilibrium', which depends on the timescale employed. As it turns out, the timescales that nature uses—which can encompass thousands and even millions of years—cannot be compared with the century long timescale used in climate models. A recent online article, published by Nature Geoscience, states that accurate prediction of Earth's future warming hinges on our understanding of climate sensitivity. Moreover, only by studying climate change in the past, the paleoclimate, identifying all the factors involved and how they interacted can our understanding of climate sensitivity be improved.
Methane is an important greenhouse gas, 30 times more potent than CO2, but our knowledge of the methane cycle is woefully inadequate. Sediments on the ocean's floor contain immense quantities of methane and there are enormous fluxes of methane into and out of these sediments. Trapped frozen in ice, there are some 10,000 gigatons of carbon stored under the sea—twice as much carbon as contained in conventional fossil fuel reserves. Some scientists consider the release of this methane the single worst environmental danger we face as a species. A massive release of ocean floor methane could cause real runaway global warming that would have dramatic impact on life. But methane continually leaks from seabeds around the world, contributing to the total amount of carbon injected into the ecosystem. A new report finds that ocean methane concentrations have been underestimated by a factor of 10 to 20 fold.
Remember the 2010 BP Gulf Oil disaster? For 83 days it dominated news broadcasts in the US and was followed with interest around the world. Ecological activists wailed that the Gulf would never recover, alternative energy advocates demanded all off shore oil production be shut down, and the Obama administration quickly reversed its plans to open up more coastal areas for oil exploration. Now things have gone strangely silent regarding the worst ever US oil spill. A report commissioned by the reparations fund director pronounced Gulf fisheries mostly recovered and a number of scientific reports found that both oil and natural gas released by the spill had amazingly disappeared. Some environmentalists are still howling but the crisis seems to have passed much more quickly than even the most optimistic predictions.
Climate alarmists have been slow to learn that their over-reliance on computer models and unproven theories has harmed their public credibility. In an attempt to counter the richly deserved bad press that climate science has been garnering these days, a number of global warming true believers are trying a different, more fact based approach to scaring the public. One such attempt recently appeared in the journal Science—not as a paper describing original research but as a perspective article. In it, a Senior Scientist at the National Center for Atmospheric Research, in Boulder, Colorado, attempts to “weave together” some carefully selected “threads in the discussion of climate” to arrive at a very familiar and unconvincing conclusion.
Scientists believe that carbon released from the ocean floor played a key role in past episodes of climate change. Around 55 million years ago, the break-up of the northeast Atlantic continents was associated with the injection of large amounts of molten magma into seafloor sediments. Formation of the North Atlantic basalts heated the carbon-rich sediments, triggering the release of large quantities of methane and carbon dioxide into the ocean and atmosphere. It has been suggested that this release of previously sequestered carbon was responsible for a 100,000 year period of rapid temperature rise known as the Paleocene-Eocene Thermal Maximum or PETM. Three letters published in Nature Geoscience suggest that carbon trapped beneath the seabed continues to influence carbon dynamics, at least in the deep ocean.
Much has be written and even more said about stopping climate change. The total foolishness of such a quest is obvious to anyone with even the most cursory understanding of Earth's climate over the Past 65 million years. The more science learns about the ever changing nature of climate the more capricious nature appears and the less significant the labors of H. sapiens are revealed to be. To place the ludicrous arguments and unsubstantiated fears of climate catastrophists in perspective, it is instructive to survey Earth's climate since the demise of the dinosaurs—the geological time period called the Cenozoic Era. During this long span of time, Earth's climate has undergone a significant and complex evolution. If one truth has been discovered by human science it is that Earth's climate is always changing, driven, as one set of researchers put it, by trends, rhythms and aberrations—the mechanisms of climate change.
Though Earth and its climate are billions of years old, climate science is still very young. So young that surprising new discoveries are constantly being made. One such discovery in the field of paleoclimatology—the study of Earth's climate in the distant past—was the uncovering of a period of great warming around 40 million years ago, in the middle of the Eocene Epoch. In the midst of a general cooling trend beginning at the end of the preceding Paleocene Epoch (~55 mya) there were a number of dramatic, sudden bursts of global warming. The most celebrate of these is the Paleocene-Eocene Thermal Maximum or PETM, when surface temperatures rose by 5-7°C. Recently, science has discovered another hot interval 15 million years later during the Middle Eocene. Named the Middle Eocene Climatic Optimum (MECO), it marked a time when deep sea temperatures rose about 4-5°C and atmospheric CO2 levels peaked. As new information is uncovered, climate scientists are scrambling to interpret what caused this second, more sustained period of warming and what it may mean for current climate conditions.
One of the scary predictions made about the impact of global warming is the extinction of many current species leading to a crisis in biological diversity. Like most of the speculative effects of global warming, this prediction is not only without scientific basis, it is precisely backward. A new paper in the journal Science, studying the impact of rapid global warming at the Paleocene-Eocene boundary, show that rapid tropical forest diversification occurred without plant extinction. Moreover, diversity seemed to increase at higher temperatures, contradicting previous assumptions that tropical flora will succumb if temperatures become excessive. The tropical rainforest was able to flourish under elevated temperatures and high levels of atmospheric carbon dioxide, in contrast to speculation that tropical ecosystems were severely harmed by the heat.
Climate scientists continue to be fascinated with the Paleocene–Eocene Thermal Maximum (PETM), which took place about 55 Myr ago. This period of sudden global warming and increasing atmospheric CO2 represents a possible model our present era of warming climate and growing CO2 emissions. Studying the PETM, therefore, may provide insight into climate system sensitivity and feedbacks. Just such a study, reported in Nature Geoscience, found that CO2 forcing alone was insufficient to explain the PETM warming. Scientists speculate that other processes and/or feedbacks, hitherto unknown, must have caused a substantial portion of the warming during the Paleocene–Eocene Thermal Maximum. Simply put, CO2 did not cause the PETM climate change.
A new paper, penned by a group of known warmist scare mongers, claims to have proof that CO2 is the control knob that regulates Earth’s temperature. Andrew A. Lacis, Gavin A. Schmidt, David Rind, and Reto A. Ruedy, all from NASA's Goddard Institute for Space Studies, are boasting they have experimental proof that “carbon dioxide is the single most important climate-relevant greenhouse gas in Earth’s atmosphere.” Even though this climate alarmist cabal admits that H2O, in the form of water vapor and clouds, accounts for 75% of greenhouse warming, they still claim that that CO2 is king. Why? Because water's contributions are supposedly caused by feedbacks involving carbon dioxide. How have they proven that? By fiddling around with the same biased computer climate models that their other fictitious claims are based on.
Like an overly familiar maniac from a series of Hollywood slasher movies, CO2 has lost most of its ability to scare the public. Carbon dioxide's diminishing fright mojo has sent climate change alarmists—and those in the media who lend them mindless support in trade for salacious headlines—casting about for a next gas molecule to scare the public with. A few trial balloons have been floated for oxides of nitrogen (NOx) but the rising star in the global warming shop of horrors is methane (CH4). Aside from having a familial relation ship with CO2 based on carbon, CH4 is a known greenhouse gas and is produced almost everywhere on Earth by decaying organic matter. Most recently, there were panicked warnings that Arctic seabed methane stores were being destabilized. The hype over methane has gotten so out of hand that a news focus article in Science (which is not a hot bed of climate change skepticism) has publicly stated the situation is being exaggerated.
Throughout Earth’s history, there is evidence of large carbon dioxide releases, greenhouse conditions, ocean acidification, and major changes in marine life. About 120 million years ago (mya), during the early part of the Cretaceous period, a series of massive volcanic eruptions pumped huge amounts of carbon dioxide into Earth's atmosphere. During the Aptian Oceanic Anoxic Event, atmospheric CO2 content rose to about twice today's level. Eventually, the oceans absorbed much of that CO2, which significantly increased the water's acidity. The change reduced the amount of calcium carbonate (CaCO3) in the water, making it difficult for creatures such as some kinds of plankton to form shells. But the plankton did not die out. In fact, the geological record indicates that ocean biota can adapt to CO2 concentrations as high as 2000 to 3000 ppm—five to eight times current levels.