Concatenation Science Communication News

Winter 2019 Earth System transitions: How resilient is the biosphere?  More continuing professional development (CPD analogous to CME for biomedical visitors) with a two-day symposium on the afore topic.  This sort of ties in with the NERC Biosphere Evolution, Transitions & Resilience research programme and which builds upon the 2012 Neoproterozoic Era: Evolution, Glaciation and Oxygenation Snowball Earth II and the 2011 Life & the Planet symposia, all of which were run by the Earth System Science group of the Geological Society.

          It has to be said that this was a bit of a hotchpotch of papers rather than an exposition of a particular science narrative: this event was really a catch-up on some of the areas of current Earth system science research.  No problem here as it has been seven years (really, that long!) since these last symposia.
          Ground covered included:  a major pulse of carbon dioxide contributed to the end-Permian extinction (this chimed with 2018 Mass Extinctions symposium and the 2017 Royal Society Hyperthermals symposia (which I see I failed to blog about previously));  end-Permian mutations possibly caused by heavy metal release or UV light following ozone depletion;  the use of 7Li as a proxy for silicate weathering;  and that across deep time since the Cambrian the long-term trend in declining extinction rates suggests that the Earth-system is, in long-term terms, becoming increasingly resilient, but that the system is currently in a semi-stable mode (and so now is not a good time to give it a greenhouse kick).
          Tyler Volk, visiting from the US, gave an intriguing narrative talk on the evolutionary progression from prokaryotes, to eukaryotes, to multicellular life, to socio-biological groups and the possible forthcoming planet-wide organisational structures.  Lee Klinger, again from the US, gave examples of traditional native American, as well as early colonist strategies, that we seem to have forgotten but which do confer ecosystem-level resilience.
          Sadly President Trump's shutdown of governmental expenditure prevented Douglas Erwin of the Smithsonian giving a plenary on evolution, resilience and stability in the Phanerozoic. (I was looking forward to that.) The Trump-caused uncertainty meant that the symposia's abstract booklet was not produced as a hard copy. Fortunately, meeting secretariat Ruth Davey kindly printed out the PDF for me (a perk of being a Geological Society Fellow?): after all, one needs to make notes annotating the abstracts when attending symposia.

 


Argo float deployment. (© Cheng et al [see text right] reproduced under fair use in the context of a review .)

Winter 2019 New estimates indicate faster ocean warming.  One of the audience questions oft asked in my climate change talks of the early 2010s was how come global warming seems to have stalled?  This is because the Climatic Research Unit and the UK Met Office data for warming showed that since the 1998 peak, through to 2013, there was no extra warming.  This helped fuel climate deniers' arguments in the 2000s.  Actually what was likely happening, as I would point out, was that the aforementioned climate data related to surface temperatures; it ignored the heat within the oceans.  We did have some data but it was not as complete as the data gained from surface monitoring.  The data is still incomplete (especially for waters below 2km) but as Lijing Cheng, John Abraham, Zeke Hausfather and Kevin E. Trenberth, have just pointed out, in a perspective paper in the journal Science, we are slowly getting a better handle on ocean temperatures.  Part of this improvement in understanding comes from the Argo network of some 3,000 buoys in the early 2000s that measure temperatures in the top 2 km of the oceans.
          These have confirmed that the planet's oceans have absorbed about 250 x 1021 joules (250 zettajoules) between 1990 and 2018.  This figure is in broad agreement with the latest Earth system computer models.  Combining these real-life measurements with the models, suggests that the oceans have absorbed around a third more energy (in terms of watts per square metre) than the IPCC's 2013/4 Assessment Report 5 concluded.  Because of thermal expansion of water, this has a considerable impact on sea-level rise projections which now have to be revised upwards.
          This is something I have long-time argued given that the glacial to interglacial sea-level rise (20,000 to 15,000 years ago) was at times up to 3 metres a century, which is far greater (four or five times) than the IPCC worse case forecast estimates for the 21st century.  (I mentioned this in my books Climate and Human Change (1998) and Climate Change: Biological & Human Aspects (2013) pages 334-5.)  Of course, the greenhouse kick we have given the Earth system, in the 20th century combined with that estimated for the 21st century, is greater than that which naturally occurred in the last glacial-to-interglacial transition.  The reason I have not given warning of possible, even greater sea level rise is because of inertia of the Earth system: it takes time for the system to adjust. Also, I do not want to appear alarmist.
          See Cheng, L. et al, 2019, How fast are the oceans warming? Science, vol. 363 (6423), p128-129.

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