Welcome To The Anthropocene
In an essay adapted from his 2009 AAAS Annual Meeting keynote address, James J. McCarthy has produced a fairly concise statement of the anthropogenic global warming believer's world view. After a self-serving review of climate science history, McCarthy trots out the usual litany of climate change troubles: increased cyclones, rain and floods, rising sea levels and, of course, those pesky tipping points. The tone of the article is set early on, when research is cited stating that mankind's impact on Earth is “sufficiently profound to declare that we have transitioned from the Holocene era of Earth history to the Anthropocene.”
McCarthy, professor of Biological Oceanography at Harvard and outgoing president of the AAAS, has done an admirable job in summarizing the main stream, “concensus view” version of climate science. His article, titled “Reflections On: Our Planet and Its Life, Origins, and Futures,” appeared in the December 18, 2009, issue of the AAAS journal Science. He begins with a quick rundown of how the CO2 centric AGW theory developed—a history that could have been cribbed from The Resilient Earth.
The tale begins in 1859, the year that “Irish chemist Sir John Tyndall discovered that CO2 absorbs infrared energy as a radiatively active constituent in Earth's atmosphere.” He correctly credits Joseph Fourier's earlier work attributing the temperature of Earth to the balance between incoming solar radiation and outgoing heat emissions from the planet. According to this version of science history, Tyndall discovered that the balance is determined by the composition of the atmosphere, notably the “concentration of CO2 and aqueous vapor.”
Tyndall was indeed an important figure in the development of atmospheric physics and understanding climate. In The Resilient Earth, we quoted Tyndall waxing poetic about the aqueous vapor (ie. water vapor):
Aqueous vapour is a blanket more necessary to the vegetable life of England than clothing is to man. Remove for a single summer-night the aqueous vapour from the air which overspreads this country, and you would assuredly destroy every plant capable of being destroyed by a freezing temperature. The warmth of our fields and gardens would pour itself unrequited into space, and the sun would rise upon an island held fast in the iron grip of frost.
Note that Tyndall didn't mention CO2 while McCarthy lists it before the aqueous vapor. As Tyndall well understood, H2O, the aqueous vapor, is the primary greenhouse gas in Earth's atmosphere. For what reason could McCarthy have given CO2 primacy of place, insinuating that Tyndall was most impressed by CO2's contribution to Earth's climate? This subtle manipulation of history is just a foreshadowing of things to come.
Next comes a recitation of more events from 1859: Edwin Drake's successful oil well in Titusville, Pennsylvania, and Lenoir's invention of the spark-ignited internal combustion engine. “Physical and biological systems in the ocean and on land that remove CO2 from the atmosphere are unable to absorb or assimilate additional CO2 at the rate at which it is being produced by the combustion of fossil fuels,” McCarthy opines. “More than half of the fossil fuel carbon released by human activities today will remain in the atmosphere for up to a century.” All of this and McCarthy's history still hasn't progressed beyond 1859.
Introduced next is Svante Arrhenius, a Swedish chemist born in 1859—nice tie-in, eh? It was Arrhenius who first calculated the possible effects of doubling atmospheric CO2 on global temperature, work he performed around the turn of the 20th century. In an interesting choice of sequence, Arrhenius' work on CO2 is introduced prior to any mention of Louis Agassiz's theory of ice ages (c. 1840) and James Croll's work on Sun-Earth orbital cycles as a trigger for those ice ages (c. 1864).
In 1864, Croll published an article in the Philosophical Magazine, “On the Physical Cause of the Change of Climate During Geological Epochs.” In this paper Croll introduced variation in Earth's orbital elements as the likely periodic mechanisms for initiating multiple glacial epochs. What McCarthy doesn't say is that Croll's work, while greeted with some initial enthusiasm, was eventually discredited because his calculated predictions did not match the accepted timing for ice ages.
Eventually, Croll's theory would be revived by Milutin Milankovitch, a Serbian engineer and geophysicist. Milankovitch's calculations early in the 1900s on the frequency and amplitude of three components of Earth-Sun orbital relations refined Croll's theory and again, for a time, caused a stir in climate science circles. But just as with Croll's work, discrepencies between Milankovitch's calculated timings and other accepted data led to the theory of astronomical cycles being discarded once again.
Not until the 1970s did work by Emiliani and Broeker revive and substantiate the Croll-Milankovitch Cycles using new proxy measurements. None of these travails are mentioned by McCarthy. He does admit that there was little consensus within the Earth science community regarding the cycle theory until the 1970s, mainly because “orbital forcing would yield asymmetric cycles, with long glacial periods interspersed with short interglacial periods, which was counter to the prevailing view within geological sciences of four short ice ages over the Quaternary, with long warm periods between them .” In other words, the cycle theory was not accepted partially because is was not in agreement with the existing consensus view. But there are deeper lessons here that have been glossed over in McCarthy's haste to push CO2 to the center of the discussion.
The main thing not mentioned is that both Croll and Milankovitch failed to convince the scientific community of their work's correctness because they lacked sufficiently accurate historical data to base their calculations on. Also, those calculations themselves were long and tedious, quite prone to errors in an age before computers or even calculators. The scientific establishment was correct to question the cycle theory because, in both its historical incarnations, it produced questionable results due to calculation error and bad input data. Does this sound somewhat familiar? It should, for this is exactly the position that the IPCC AGW crowd finds itself in today—error prone calculations from GCM based on iffy historical data. The difference is that AGW has managed to become the accepted consensus view of a large number of climate scientists before being rigorously proven.
Today, the Croll-Milankovitch Cycle theory has become the accepted theory of ice age forcing. But its rocky road to acceptance, a clear example of how science is supposed to work, is trivialized by McCarthy's view of history. After mentioning that Arrhenius' “back-of-the-envelope” calculations suggested a possible rise of 6°C for a doubling of atmospheric CO2, McCarthy quickly skips on to Guy Callendar, the Al Gore of the 1930s, and Roger Revelle, the self-proclaimed father of global warming. Unsurprisingly, no mention is made of Arrhenius' further statement that Earth's climate might become “more equitable” if the temperature did rise.
After this myopic and self-serving jaunt through climate science history, McCarthy muses for a time about our new understanding of our fragile planet, in part motivated by three “powerful” images from taken space. The pictures in question, all credited to NASA, are: the photograph known as “Earthrise,” photographed by Apollo 8 astronaut William Anders on 24 December 1968; the photograph referred to as “The Blue Marble,” taken by the crew of Apollo 17 on 7 December 1972; and variations of “Earth at Night.”
Jasanoff has written about the power of the Earthrise and Blue Marble images to alter perceptions of our planet's vulnerability. For the most part, national boundaries are invisible in these images, and consciousness of collective human responsibility for the future of our planet is aroused by them. She compares the contrasting perspectives evoked by the image of a well-engineered "Spaceship Earth," a phrase coined by Buckminster Fuller, and that of a fragile craft at risk, as envisioned by Rene Dubos. In analyzing the iconic power of these images, Jasanoff also remarks that they "set up an unresolved dialectic between those who wish to approach environmental problems on a global scale, with gaze averted from the particularities of culture and place, and those who believe that the work of saving the planet must begin with more down-to-Earth considerations, in the realities of lived experience, with questions about the kinds of lives people want to forge for themselves, their communities, and their descendants"
With the feelgood preliminaries disposed of, now comes the real meat of the article. What follows is a recitation of the basic beliefs of climate change alarmists. Much like Saint Paul's first letter to the Corinthians, McCarthy's article is a plea for unity among climate change believers in the face of various issues raised by skeptics. Like that epistle, the tenants of faith are layed out—humans are harming the planet in a myriad of ways, anthropogenic CO2 is primarily to blame, the IPCC models are correct, things are probably worse than they seem, and so on.
We have heard this all before. For example: “A sea-level rise of 0.8 to 2 m over the next nine decades would be of enormous consequence for lives, livelihoods, and property in coastal regions across the globe. Major cities, large portions of nations, indeed entire island nations will become uninhabitable. Add additional tropical storm intensity, and damage from any rise in sea level becomes intensified.” Yet experts have stated that sea-levels aren't rising and tropical storms not increasing in either intensity or frequency. Indeed, tropical storm activity is at a 30 year low.
There is the usual collection of graphs and charts, plotting the world's demise at the hands of neglectful humans. One in particular stands out, a colorful chart showing the global ranked surface temperatures for the warmest 50 years according to the Met Office of the UK's Hadley Centre, ground zero for the climategate scandal. The size of the bars indicates the 95% confidence limits associated with each year. The source data are blended land-surface air temperature and sea surface temperature from the HadCRUT3 series. Values are simple area-weighted averages for entire years.
While this is a pretty graph, with years from each 20 year period in a different color, it is by its very nature misleading. This is because the years are arranged by temperature not chronographically. While the primary intent is to show that the hottest years occurred mostly over the past two decades, by ordering the data in this way there is an impression of a smooth, inexorable increase in temperature (the arrow points to 2008). By removing the impact of natural variation over time we see yet another misleading “hockey stick” graph. Science is not supposed to be based on parlor tricks or optical illusions.
What would such a sermon be without a little fire and brimstone? That is provided by warnings about global warming's favorite daemon, the infamous tipping point:
Several recent scientific papers and reports have addressed tipping points. Lenton et al. broaden this concept by defining tipping elements as subsystems of the Earth system that are at least subcontinental in scale and can be switched, under certain circumstances, into a qualitatively different state by small perturbations. The authors take into consideration equilibrium properties, threshold behavior, and critical rates of forcing, and suggest how this analysis can be of policy relevance in decision-making. A range of adverse impacts of abrupt climate change can be compared to develop cautionary strategies via a forewarning system.
Much like St. Paul's second letter to the Corinthians, McCarthy's article is in part a defense of climate science's ministry. In a strange twist on the doctrine of weakness being strength, the faults of the IPCC reports are called out as reasons to believe even more fervently in global warming:
Over the past two decades, many of the future climate projections from the IPCC and other groups have been proven to be conservative. This is in part because an IPCC assessment is by its very nature highly conservative. The content of an IPCC assessment is based on peer-reviewed publications in scientific journals. Thus, the most recent findings, perhaps already widely known among experts, may not be included in an assessment report if the work has not been published. Furthermore, recently published findings that have yet to be corroborated by other investigators may receive less emphasis than well-established work from an earlier period...
Unfortunately, when data confirm that projections for future climate have been overly conservative, this implies more serious negative impacts. Some aspect of the projected rates for greenhouse gas emissions or for the modeled climate response to these emissions has been underestimated.
So, welcome to the Anthropocene era, when humanity confesses to its sins against nature and repents its CO2 emitting ways. As penance the developed nations will lay waste to their industrial economies and the developing world abandon their dreams of a prosperous future. But even after bemoaning the decline in funding for Earth observations in NASA's budget, the catalog of worsening conditions, and warnings that “there may yet be surprises” McCarthy finds succor in the new leadership of the Obama administration. “Never before have scientists been so influential in their active support of sound government policies, nor as selfless in accepting positions of great responsibility in the governance of our nation.” So here is his earnest plea—keep the faith. And make no mistake, belief in anthropogenic global warming has become a mater of faith not science.
Be safe, enjoy the interglacial and stay skeptical.