1 May 2015

No easy listen


I have written here before of Andrew Glikson, geologist and climate informer. This was a public lecture on the atmosphere, past present and future. Santayana is quoted saying "Those who cannot remember the past are condemned to repeat it". The atmosphere also has a history and it's expressive through science. (The list of proxies used to indicate climate over geological time was particularly fascinating). I have heard much of this. Anyone with an open intellect cannot but freak at the story being presented. There are constant reports of new studies, mostly drastically and repetitively frightening, occasionally something hopeful in a minor clarifications in a positive direction. Clearly it's a troubling (actually, massively scary) story that science is telling. Just today I read of advice to the Abbott Government from the Australian Academy of Science, but I don't expect much real response. The Government talks of accepting the science, but, to borrow the wisdom of another relevant quote, "By their fruits you shall know them" most interestingly following the preamble "Beware of false prophets" (Bible, Matthew, 7:15-20). Mmmm. But back to Andrew. He spoke of the early history of the Earth, of mass extinctions, of volcanoes and impacts, of changing climate. (Yes, Virginia, the climate has changed, but we have only had civilisation for 10,000 years of 4.5 billion and these years have been in a very benign climate). Also, of the uniqueness of water, of homeostasis against the "faint sun paradox" (new to me) and the role of the greenhouse gas blanket. Of the atmosphere as the "lungs of the biosphere". Of rapidity of change (the current rate of change is extraordinary and perhaps the greatest danger in climate change); of tipping points (another greatest danger; for this topic, I will allow more than one "greatest" danger :->); of glacial periods and interglacials (the last glacial termination was ~14,000 years ago, notably close to the birth of civilisation); of the current situation of ~+2degC positive forcing (from CO2 and other greenhouse gases, lasting 10,000s of years) and ~-1degC negative forcing (from aerosols like soot in the atmosphere, which stay there for only months) giving our current ~+0.8gegC increased temp over just a few hundred years and mostly from post-WW2. Makes ya worry. We are heading for +3/4degC by 2100 (yes, Virginia, just 85 years hence) which is approaching Pleistocene temperatures. What of agriculture, sea levels, sea temp ... and those tipping points? You would laugh if it weren't so scary. I've quoted our own Frank Fenner here before: "Homo sapiens will become extinct, perhaps within 100 years ... It’s an irreversible situation. I think it’s too late." Andrew mentioned Carl Sagan's pessimism and this quote that I found is relevant enough: "I once asked Carl Sagan if he thought there was any other intelligent life in the universe. He paused and said. 'No. Because if any species had reached our stage of evolution, they would have destroyed themselves.' " (The nuclear age and future generations / Helen Caldicott. IN Crisis without end / ed. Helen Caldicott. NY : New Press, 2014, p.225). Makes you laugh, really. Best wishes to the Paris convention for our kids' sakes.

Andrew Glikson gave a public lecture at ANU entitled Atmosphere : past present and future.

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