The current interglacial warm period, the Holocene, started ∼11,500 years ago. At its start, among the dramatic changes in climate was a notable increase in rainfall, triggered by summer insolation values higher than those of today. This caused what is called the African Humid Period in North Africa—a time when the Sahara was dotted with large and small lakes, savannah grasslands, and in some regions, humid tropical forests and shrubs. The African Humid Period ended abruptly ∼5000 ybp (years before present) in many locations, such as western North Africa and northern Kenya. In other places, such as the central Sahara and the southern Arabian Peninsula, change occurred more gradually, taking several millennia. Regardless of the pace of change, those areas are tracts of arid desert today, and the animals and humans who had previously thrived in those formerly verdant regions have either moved or had to adapt to much harsher conditions. This is but one example of nature at its most capricious—the tyranny of climate change.
Climate alarmists are constantly warning that Earth is going to warm up, driven they say by the level of CO2 in the atmosphere. To bolster their claims they point to the Pliocene, a time 4-5 million years ago, when the planet was 4-8°C hotter and CO2 levels were 400ppm or higher. This is the climate we are heading for, the global warming supporters say—but it that really true? Superficially it seems a plausible assertion, but as it turns out there is much more here than CO2 and temperature. It is not just the average temperature but the distribution of temperature at different latitudes, both over land and sea, that controls the climate. It is the temperature gradient that drives storms and affects weather patterns and it was much different during the Pliocene. Moreover, climate models do not generate a Pliocene like climate when run with higher CO2 levels, which means climate scientists are missing something important about the way Earth's climate system works.
Scientists have long suspected that the orbital cycles of our planet are responsible for the periodic climate variation that causes alternating glacial and interglacial periods. Milankovitch's theory of orbital cycles suggests that summer insolation at high northern latitudes drives the glacial cycles. Moreover, statistical analyses have demonstrated that the glacial cycles are indeed linked to eccentricity, obliquity and precession. Now, researchers have confirmed that a combination of two of the Milankovitch cycles conspire to start and stop ice ages. The 100,000-year eccentricity cycle amplifies the influence of the 23,000-year wobble of Earth's spin axis called precession. The new modeling also suggests that the great accumulation of mass by the North American ice sheet causes the abrupt end of glacial periods. CO2 is involved, but is not determinative, in the evolution of the 100,000-year glacial cycles say the scientists.
Scientists who study climate will tell you that today's warm temperatures and mild conditions are not normal for Earth during the past several million years. Our planet has been in a general cooling trend for 35 million years and in the grip of an Ice Age for the last 1.6 million years. What's more, this Ice Age, known as the Pleistocene, consists of relatively short periods of warmth, called interglacials, separated by much longer periods of bitter cold, referred to as glacials. The recorded history of humankind covers only the later half of the most recent interglacial warming, though our ancient ancestors did leave messages in the form of cave art that date back to much colder times, times when the Ice Age held the world fast in its frozen embrace. Predicting the timing and duration of these periods remains a problem for scientists. Why the glacial periods should last around 100,000 years, as they have for the last million years or so, is called the 100-kyr problem. Now, a group of researchers claim they know the answer.
Sometimes scientists show their whimsical side by applying the tools of their profession to things outside the realm of science. Such was the case when a team of graduate students at the Department of Physics and Astronomy at Johns Hopkins University, decided to look into the oddly inconsistent seasons on the planet Westeros, the world invented by George R. R. Martin in A Game of Thrones. The group recently published a paper in which they explore the possible cause of summers lasting for years and winters for a generation. Using a numerical three-body computer simulation the intrepid researchers reach the conclusion that such a world is possible in the non-mythical universe.
Most people have never heard of the Anthropocene era and with good reason—it is not an officially recognized geologic time period. It is the invention of a small group of scientific busy bodies who evidently have nothing better to do than try to effect a change in the official timeline of Earth's past. The International Commission on Stratigraphy, the body charged with formally designating geological time periods, has been petitioned in the past and just recently a group of chuckle-heads attending the Society for American Archaeology meetings in Hawaii have brought the idea up again. Only problem is, the proponents of the Anthropocene have fallen to arguing amongst themselves—when did the “Age of Man” really start?
For some reason a lot of people have become fixated on Antarctic ice—is it waxing or waning, accumulating or melting. Climate alarmists have striven mightily to show that ice at the poles in on the decline, melting in the face of rising global temperatures. Antarctica, with the largest store of glacial ice on the planet, is the primary focus of attention. If Antarctica’s ice sheets were to melt it would be a calamity for mankind. Unfortunately, Earth's climate system contains many cyclic trends, operating on decadal and longer periods of time. In the past, what some claim are clear trends have turned out to be only short term in nature. A new report, just published online, concludes that it is unclear if changes in atmospheric circulation over West Antarctica during the past few decades are part of a longer-term trend. In fact, ice cores reveal a significant increase in the oxygen isotopes from precipitation over the past 50 years, but the anomaly cannot be distinguished from natural climate variability.
Gas prices, oil sands, fracking and the Canadian pipeline have all thrust energy back into the headlines. Politicians posture, eco-alarmists protest and those global warming fanatics continue to predict the end of the world as we know it. If you are tired of the hype and disinformation, if you really want to understand energy—where it comes from, how it works and how much of it the world has—then you need a copy of The Energy Gap. In this follow-on to The Resilient Earth, Hoffman and Simmons address the world's energy questions with the same wit and erudition displayed in their previous work. Even better, in honor of April 15th, tax day in the US, you can now download a copy of The Energy Gap for free from Amazon.
It has been vilified in the press and maligned in school classrooms by the ignorant. Opposing it has become a cause célèbre in Hollywood an a litmus test for liberal politicians. Labeled man's chosen weapon for ravaging nature and laying waste to the environment this poor, largely misunderstood gas is in fact essential to our existence. Without carbon dioxide, CO2, we would not be here and Earth would be a frozen lifeless chunk of rock. Forget that life would never have developed on a planet without greenhouse warming, a recent scientific study say the daemon gas has rescued the planet from the deep freeze at least twice during the Neoproterozoic era, roughly 750 to 635 million years ago.
It's everywhere on Earth, on the other planets and moons of the solar system, and even in comets from deep space. It is the frozen form of water, commonly called ice. Something so ubiquitous and familiar, one would think that science knows a lot about ice. It turns out science knows less than we might suppose. In a commentary in the journal Nature, an ice scientist raises ten open questions about ice. For example, the article states: “We cannot predict with certainty when and where ice clouds will form in the atmosphere; areas of the sky remain humid when we would expect them to freeze.” Ice is a fundamental part of Earth's climate, yet these questions and others remain unanswered. How can climate science claim to predict the fate of the polar ice sheets or mountain glaciers when we do not really understand the substance that they are made of?
Something happened this year that has become rare in recent times, much of the United States has had a white Christmas. As of December 28th, 64.4% of the US was covered by snow with an average depth of 6.2 inches (15.7 cm). This compares with last month's coverage of only 19.8%. My own town of Conway, Arkansas, received 10 inches on Christmas day and a winter storm advisory is in effect as another storm makes its way eastward. For Arkansas, this has been the snowiest Christmas ever, breaking the old record set in 1926, and the 7th snowiest day overall since 1875. But North America is not alone in feeling winter's bite—record cold continues in Siberia, while a vicious cold snap across Russia and Eastern Europe has claimed nearly 200 lives. What does all this say about global warming?
A new “comprehensive” report about the melting of Antarctic and Greenland ice sheets is being touted by climate alarmists as “grim news” but in fact says no such thing. This latest estimate, published this week in Science, combines data from many sources including 20 years of satellite data and 32 years of ice-sheet simulations to arrive at a mixed conclusion. It estimates that, between 1992 and 2011, the Antarctic and Greenland ice sheets lost 1350 ± 1010 and 2700 ± 930 Gt of ice, respectively. That is equivalent to an increase in global mean sea level of 11.2 ± 3.8 mm, less than 1/2 an inch. Moreover, while some areas were losing ice mass others were gaining mass from snowfall. The East Antarctic Ice Sheet (EAIS), which occupies over 75% of Antarctica, experienced mass gains during the final years of the study.
Instrument data from the last 160 years indicate a general warming trend during that span of time. However, when this period is examined in the light of palaeoclimate reconstructions, the recent warming appears to be a part of more systematic fluctuations. Specifically, it is an expected warming period following the 200-year “Little Ice Age” cold period. Moreover, a new study of the natural variability of past climate, as seen from available proxy information, finds a synthesis between the Milankovitch cycles and Hurst–Kolmogorov (HK) stochastic dynamics—a result that shows multi-scale climate fluctuations cannot be described adequately by classical statistics.
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).
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.