“Good planets are hard to come by” – a note from Andrew Glickson
“Good planets are hard to come by” – a note from Andrew Glickson
6 February 2010 Posted by OveHG 150 views No Comment
Dr Andrew Glick is an earth and paleoclimate scientist from the Australian National University.
“We’re simply talking about the very life support system of this planet.” (Joachim Schellnhuber, Director, Potsdam Climate Impacts Institute, advisor to the German government).
The release of more than 320 billion tons of carbon (GtC) from buried early biospheres, adding more than one half of the original carbon inventory of the atmosphere (~590 GtC) to the atmosphere-ocean system, has triggered a fundamental shift in the state of the atmosphere at a rate of 2 ppm CO2/year, a pace unprecedented in the geological record with the exception of the effects of CO2 released from craters excavated by large asteroid impacts.
Recent paleoclimate studies, using multiple proxies (soil carbonate δ13C, boron/calcium, stomata leaf pores), indicate that the current CO2 level of 388 ppm and CO2-equivalent level of 460 ppm (which includes the methane factor), commits warming above pre-industrial levels to 3 to 4 degrees C in the tropics and 10 degrees C in polar regions , leading to an ice-free Earth.
Such conditions existed in the early Pliocene (5.2 Ma) and mid-Pliocene (2.8 Ma) Pliocene, about the time Australopithecine bipeds were emerging from tropical forests . Pliocene climates changed gradually and pre-historic humans responded through migration. There is nowhere the 6.5 billion of contemporary humans can go, not even the barren planets into the study of which space agencies have been pouring more funding than governments allocated for environmental mitigation to date .
It appears difficult to explain to the public and politicians that, at 460 ppm CO2-equivalent, the climate is tracking close to the upper stability limit of the Antarctic ice sheet, defined at approximately 500 ppm . Once transcended, mitigation measures would hardly be able to re-form the cryosphere, which serves as the Earth’s thermostat, from which cold ocean and wind current emanate – keeping lower latitudes cool. Once the ice melts the atmosphere-ocean system shifts to greenhouse Earth conditions such as existed about 15 Ma (mid-Miocene), before 40 Ma (Eocene), and much of the Cretaceous (141 – 65 Ma), when only small burrowing mammals could live on land.
About 2.8 Ma, the mid-Pliocene, temperatures rose by at least 3 degrees C above pre-industrial and sea levels rose by 25+/-12 meters . About 15 million years ago the rise of CO2 to near~500 ppm resulted in global temperatures about 4 degrees C above pre-industrial level and sea level by about 40 meters. Since the early 20th century the rate of sea level rise increased from about 1 mm/year to about 3.5 mm/year  (1993 – 2009 mean rate 3.2+/-0.4 mm/year (Figure 1).
Figure 1: Sea level changes 1993 – 2009 scanned by the Topex and Jason satellites. University of Colorado, 2009 (http://sealevel.colorado.edu/)
The world is in a lag period, when the consequences of human greenhouse gas emissions and land clearing are increasingly manifest, including atmospheric energy levels which drive hurricanes and is shifting climate zones toward the poles, with consequent desertification of temperate zones, i.e. southern Europe, southern Australia, southern Africa. The desiccated forests become prey to firestorms, such as in Victoria and California.
Global warming is modulated by the ENSO cycle, including relatively cool La-Nina phases (Figure 2). Studiously ignorant climate change deniers, who would like to call themselves “sceptics”, use these cycles to claim “global cooling” . In contravention of basic laws of thermodynamics (Stefan-Boltzmann law, Kirchoff law) which underlie the infrared absorption/emission resonance effect of greenhouse molecules, they invoke the role of short-lived (9 days average atmospheric residence) water vapour but neglect the long-term effects (centuries to millennia) of the well-mixed CO2 and nitric oxides. The increased frequency of the El-Nino is tracking toward conditions of permanent El-Nino, free from the effects of polar-derived currents (Humboldt Current, California Current). Such conditions existed about 2.8 Ma ago  (Figure 3).
Figure 2: Mean global temperature trend 1975 – 2009 and the ENSO cycle, representing the superposition of the El-Nino – La Nina cycles on the global warming trend."
Climate change is appropriately described as a global oxygenation event affecting geological carbon deposits as well as the present biosphere. At 2 ppm/year the scale of carbon oxidation exceeds the highest recorded geological rate of 0.4 ppm/year, recorded at the Paleocene-Eocene boundary at 55 Ma when about 2000 GtC were burnt, triggering an extinction of species .
Figure 3: Evolution of the ENSO (El Nino Southern Oscillation) cycles from the Pliocene (5.2 – 1.8 million years ago) to the present, showing the divergence of ocean temperatures in the east Pacific Ocean (blue line) from the west Pacific Ocean (red line).
Hopes for a meaningful binding agreement in Copenhagen, described as “the most important meeting in the history of the human species.” (Joachim Schellnhuber), and for a supposed presidential “Messiah” to wave the magic wand, collapsed in December, 2009, in the sorry mess of vested and tribal interests.
The international system required to protect the lives of the young and future generation is failing. According to the Global Carbon Project “Carbon emissions from the combustion of fossil fuels and land use changes reached almost 10 billion tonnes in 2007” . Those who deny the reality of climate change around the globe seek uncertainties in future climate projections, cf. dates of Himalayan glacier melt or Amazon deforestation. This ignores the evidence for dangerous climate trajectories even where the precise dates of future events can not be determined, namely, Himalayan glaciers melt may precede or postdate 2035. Presumably the claims of “conspiracy” on the part of the scientific world include the pioneers of atmospheric physics (Joseph Fourier, John Tyndall, Svante Arrhenius and Guy Chalendar), as well as those who defined the basic thermodynamic laws of the greenhouse process (Stefan, Bolzmann, Kirschner)?
Most of all those who criticise the IPCC ignore the fact that, to date, the IPCC reports have UNDERESTIMATED ice melt rates, sea level rise, feedback effects and the proximity of tipping points, not least the looming release of hundreds of GtC as methane from permafrost, lake sediments and bogs.
Governments continue to pour the planet’s dwindling resources into wars (US$1.4 trillion in 2008) and bank bailouts (US$0.7 trillion). Entertainment and media are projected to cost US$2 trillion in 2011. Between 1958 and 2009 the US (NASA) spent US$823 billion on space exploration searching among other for water and microbes on other planets . Now they have found water on Mars and the Moon, while pH of the terrestrial oceans has declined between 1751 and 1994 by 0.075 (8.179 to 8.104) , threatening the marine food chain.
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OveHG is Professor and Director of the Centre for Marine Studies at the University of Queensland. He completed his BSc. Hons at the University of Sydney and PhD at UCLA in 1989, and was recognized in 1999 with the Eureka prize for Research into the physiological mechanisms of coral bleaching. Specialising in the impact of climate change on biological systems, Professor Hoegh-Guldberg has worked in polar, temperate and tropical regions, and is well-known for his work on the impacts of ocean warming and acidification on coral reefs. He is currently a Queensland Smart State Premier’s fellow, and holds positions as reviewing editor at Science Magazine and chair of the World Bank/GEF working group on coral reefs and climate change.
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