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.
To ring in the new year, The Resilient Earth presents a collection of recent journal and news articles regarding climate science. Some are about actual science and others are more in the way of commentary on the state of global warming. New discoveries continue to be made, though the climate change faithful stubbornly refuse to abandon the party line: Earth's temperature is going to rise dangerously and humanity is to blame. Perhaps the most interesting development is that a number of green advocates have given up on avoiding global warming, deciding instead to stress the unfair social impacts that climate change will supposedly cause. At the end of 2010, here is a snapshot of the state of the climate change debate.
The influence of the Sun on Earth’s climate over time scales of centuries and millennia is all but ignored by current climate change dogma, with many climate scientists dismissing solar variation as too feeble to have much of an impact. Though it was recently discovered that variation at ultraviolet wavelengths is considerably greater than at lower frequencies, the change in total solar irradiance over recent 11-year sunspot cycles amounts to <0.1%. New research on longer time scales finds the change in total irradiance sufficient to affect the dynamics of the El Niño–Southern Oscillation (ENSO). Detailed model studies of the Little Ice Age (~1400 to 1850 AD) conclude that the Sun controls an “ocean dynamical thermostat” that affects climate variability over large regions of the globe. It was also found that fully coupled general circulation models (GCMs), the kind used by the IPCC to make predictions of future global warming, lack a robust thermostat response. This means that the sensitivity of the climate system to solar forcing is underestimated by current GCMs—the climate models are proven wrong again.
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.
You know, in science, there was once this thing we called the Theory of Multiple Working Hypotheses. Anathema (a formal ecclesiastical curse accompanied by excommunication) in modern climate science. So, in juxtaposition to the hypothesis of future global climate disruption from CO2, a scientist might well consider an antithesis or two in order to maintain ones objectivity. One such antithesis, which happens to be a long running debate in paleoclimate science, concerns the end Holocene. Or just how long the present interglacial will last.
Even with all of the recent scandal surrounding the purveyors of climate change pap, many in the “news media” continue to crank out party-line articles blaming all of Earth's ecological woes on humanity. After decades of trying to alarm the public over a human caused “sixth mass extinction” and more recently, dwindling diversity, some in the media just can't let go of AGW as the root of all evil. A perfect example of this appeared recently in the font of misinformation that is Yahoo News. Blaming every human activity from hunting to climate change, science writer Jeremy Hsu has once again raised the specter of that old shibboleth, the Anthropocene Epoch. This is all a part of a developing trend to elevate falling species diversity to crisis level, mainly because the world's eco-activists need a replacement issue for climate change.
According to a recent paper, human actions may have caused Earth's climate to warm much earlier than previously expected. In an article to be published in Geophysical Research Letters, and widely reported in the media, around 15,000 years ago, early hunters were a major factor in driving mammoths to extinction. Supposedly, this die-off had the side effect of heating up the planet. This is an interesting conjecture, since a letter just published in Nature Geocience reaches the opposite conclusion regarding climate and the mammoths' decline. This mammoth confusion illustrates the uncertain and even contradictory evidence that abounds in climate science.
Since the Mid-Brunhes Event, around 430,000 years ago, interglacial periods have grown warmer and their CO2 levels higher. Research confirms that Croll and Milankovitch were right: Earth's orbital cycles seem to be the cause of these documented cases of true global warming, with CO2 playing a supporting role, not the lead. Many of the catastrophic events warned of by climate change alarmists turn out to be well within the range of natural variation. Moreover, new findings indicate that the effects of the cycle induced changes, through their impact on the environment in the Southern Hemisphere, are not correctly accounted for in the IPCC models.
Large portions of the globe rely on the seasonal monsoon for water. Across much of Asia, agriculture depends on the coming of the monsoon rains. One scare tactic employed by global warming extremists is to claim that human caused climate change will keep the monsoon from coming, causing drought, failed crops and famine. In truth, science does not fully understand the complex interactions of ocean, atmosphere, and land that influence the monsoon, or how it impacts climate in other parts of the world. Now, a new Monsoon Asia Drought Atlas (MADA) provides reconstructions of summer moisture for the region going back to 1300 AD. It documents a long sequence of droughts so persistent that scientists call them “megadroughts.” These megadrought events, the worst of which may have toppled ancient kingdoms, show that unreliable monsoon seasons have afflicted mankind throughout history—long before the clamor over climate change arose.
Once again, scientists propose that planet Earth has been so altered by human activity that we are entering a new geological time period—the Anthropocene. A viewpoint article by some stratigraphic heavy hitters, just published in the journal Environmental Science & Technology, has proclaimed a new age caused by anthropogenic global warming and man's savaging of the environment. According to these experts, the effects of human activity have become so pervasive that Earth has been transformed and the 11,000 year old Holocene epoch is now a “lost world.” Is this really the start of a brave new epoch, one of our own making?
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.
Although the story of the “Asteroid that killed the Dinosaurs” has become common knowledge for most people, there are still those scientists who back alternative causes of the end Cretaceous extinction even. Volcanoes, multiple meteor strikes and even widespread forest fires have been suggested as the cause of the dinosaurs' demise. The extinction event 65.5 million years ago did coincide with a large asteroid impact at Chicxulub, Mexico, and occurred within the time of Deccan flood basalt volcanism in India. A new review article by 41 scientists in the March 5 edition of Science runs down the list of what science thinks it knows about the extinction that set the stage for the age of mammals.
Earth's climate history includes numerous incidents of rapid warming and cooling. While Pleistocene ice-age glacial terminations are arguably the most dramatic recent examples of sudden climate change, during the last glacial period the climate of the Northern Hemisphere experienced several other significant episodes when the climate rapidly warmed. Scientists call these episodes Dansgaard-Oeschger (DO) events after the Danish and Swiss researchers who documented them using ice-core studies. These rapid oscillations are marked by rapid warming, followed by slower cooling. The most prominent coolings are associated with massive iceberg discharge into the North Atlantic Ocean known as Heinrich events (HE). The melting icebergs add large volumes of cold fresh water to the ocean, disrupting circulation patterns and causing further climate changes. Scientists look to past events like these to help us understand how Earth's climate system functions—what causes our planet to cool or suddenly warm. Recently, new data on past climate changes have led one commentator to predict the end of winter skiing in the American Southwest.
The debate over anthropogenic global warming—a theory propounded by the UN IPCC—is often portrayed as an argument between deniers and true believers. The deniers supposedly claim that there is no global warming, man made or otherwise, and that the whole theory is a plot by left-wing agitators and closet socialists bent on world domination. The true believers, conversely, accept every claim of pending future disaster uttered by scientists and activists alike. As with most controversies both extreme positions are wrong and the truth lies somewhere in-between. As a scientist, I have studied the evidence and find the case for imminent, dangerous, human caused global warming unconvincing—here is why I am an AGW skeptic.
With all the predictions of short term climate catastrophes proffered by global warming alarmists it is hard to look forward to a future time on Earth. What does the future hold a thousand, ten thousand, a million years from now? Science has some predictions about that as well, though the news media have not picked up on them. What environmental changes await us on the long road ahead?