……….was the subject of Professor Richard Twitchett’s talk on 29th January.
Professor Twitchett’s talk to Coastwise members (and many visitors with an interest in the topic) was excellent and full of hard science. He illustrated how analysis of past climate change events can yield reliable information about how our current marine world may change.
Evidence from the Permian and Cretacious events includes analysis of fossil evidence from marine soft-bodied burrow size and plant stomata size under different CO2 and O2 concentrations.
Viewed over many tens of million years, current CO2 levels are low, although rising, and he pointed out that children born after 2015 are the first humans in history to live in a world of >400ppm of CO2.
An initial conclusion from a lot of research is that marine fauna will become smaller as the O2 ocean content reduces. He illustrated this with the Slimehead fish Trachithidyae, whose fossils are substantially smaller in a period of high CO2 than their modern equivalents.
Interestingly, he is turning his research attention to North Devon having realised that there is useful evidence in our local rocks.
[Pictures courtesy of Professor Twitchett and collaborators]
Drawing Conclusions from Past Climate Change Events…….