Another ‘field day’ for the press as a new research paper, entitled ‘A long-term association between global temperature and biodiversity, origination and extinction in the fossil record’, is published in the journal Proceedings of The Royal Society (Biological Sciences).
The abstract says:
The past relationship between global temperature and levels of biological diversity is of increasing concern
due to anthropogenic climate warming. However, no consistent link between these variables has yet been
demonstrated. We analysed the fossil record for the last 520 Myr against estimates of low latitude sea
surface temperature for the same period. We found that global biodiversity (the richness of families and
genera) is related to temperature and has been relatively low during warm ‘greenhouse’ phases, while
during the same phases extinction and origination rates of taxonomic lineages have been relatively high.
These findings are consistent for terrestrial and marine environments and are robust to a number of
alternative assumptions and potential biases. Our results provide the first clear evidence that global climate
may explain substantial variation in the fossil record in a simple and consistent manner. Our findings may
have implications for extinction and biodiversity change under future climate warming.
Of course, the press don’t have time to read it and the authors qualify the findings of the study in the text:
“A first qualification is that our results relate to the effects of residuals from the long-term trend. An increase in global temperature may therefore cause an increase in extinction rate but not necessarily an absolute decrease in biodiversity because the underlying trend is for biodiversity to increase over time.”
“A second qualification is that the coarse time scale of our data does not allow us to make short-term predictions,
although short-term effects also cannot be excluded.”
“Finally, although we have shown an association between temperature and both biodiversity and taxonomic rates, this association may not be causative. Deducing causation from correlation is, of course, difficult. The lags shown in some of our analyses suggest that temperature is affecting biodiversity and evolutionary rates, but well known links between organisms and geophysical processes suggest we should not yet rule out the opposite direction of causation (Rothman 2001).”
CO2 gets a mention:
“When atmospheric CO2 concentrations were included as an explanatory variable in our analyses, temperature
always remained significant, and CO2 was normally not significant. CO2 was significant for both marine genus origination and extinction rate, and in the latter case was a stronger predictor than temperature. Overall, temperature was the better predictor of diversity and taxonomic rates.”
The BBC News website goes with Climate threat to biodiversity
“Global temperatures predicted for the coming centuries could trigger a mass extinction, UK scientists have warned.”
Australia’s ABC News gets rather carried away and headlines with Global warming to cause mass extinction: report
“Researchers in Britain say in the long term, global warming could lead to a mass extinction of animals and plants.”
Whilst we are on the subject of climate warming and cooling, how has man fared specifically in the UK over the past 700,000 years?
If we turn the clock back 12 months, we have this report on the BBC News website with a nice graphic:
Eight times humans came to try to live in Britain and on at least seven occasions they failed – beaten back by freezing conditions. Scientists think they can now write a reasonably comprehensive history of the occupation of these isles. It stretches from 700,000 years ago and the first known settlers at Pakefield in Suffolk, through to the most recent incomers just 12,000 years or so ago (the end of the last great ice age). The evidence comes from the Ancient Human Occupation of Britain Project.
“Australian aboriginals have been in Australia longer, continuously than the British people have been in Britain. There were probably people in the Americas before 12,000 years ago,” Professor Stringer explained.
So there you have it – in the cold we die, in warm intergalcials we thrive.