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:
Britain’s human history revealed
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.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
“in warm interglacials we thrive” WE DO?
As a species overall perhaps – but if your ancient society if affected by droughts, floods and disease whole sub-groups of humans didn’t thrive. Thrive with what mortality rate?
There’s a fair bit of the “romantic aboriginal” notion in the above comment.
What’s different between now and a world with early humans – 9 billion people all potentially impacted by climate with a short run food supply others produce for us, an interdependent and interlinked global economic system, powerful nation states and nuclear weapons. Limiting arable land and freshwater supplies. And natural systems are now ecological islands separated by large tracts of farm land. How easy is it for many species to move to adapt.
Yep as Bob Carter likes to say – climate has changed in the past and we’re all still here. Well Bob and the rocks might be – a lot of humanity and natural systems have perished in the long run too.
But if you’re cool with the odd bout of episodic death and species extinctions – well it’s cool then (or is it warm?). Trust a bloody geologist to be more interested in the rocks than the biota.
Perhaps we could have a National Sorry Day for Thalacoleo carnifex.
http://www.johnhawks.net/weblog/reviews/archaeology/upper/australian_megafauna_trueman_2005.w
How’s the data analysis going, Luke? I’m eagerly awaiting your report.
I want to see the bodies.
Errr – no documentation as I previously said. So failed I’m afraid to archive propelry. tsk tsk.
James – pervert.
Is species richness per unit area greater at the warm equator than at the cold poles? If so, why would global warming decrease species richness?
“So there you have it – in the cold we die, in warm intergalcials we thrive.”
The evidence for the ebb and flow of the colonisation of the British Isles by a single species says nothing about biodiversity.
“Is species richness per unit area greater at the warm equator than at the cold poles? If so, why would global warming decrease species richness?”
My understanding is that species at higher latitudes have evolved to cope with a climate where the range between maximal and minimal temperatures is significantly larger. At lower latitudes, seasonal differences are less marked. Species which are tuned to a more stable climate have less ability to cope with extremes.
Thanks Noel,
But would this lead to greater, less, or the same species richness per unit area in a generally warmer world, with narrower climatic extremes?
And Davey you call yourself an ecologist?
The Sahara is close to the equator – species richness??
Southern Ocean is pretty diverse and bountiful!!
Your mileage may vary.
Anyway what a STUPID argument – it’s not the warming so much as the pace of change and consequent effect on tails of the distribution – floods, droughts, seasonal patterns, co-adpated species.
And what little bit of heath in Davey’s cool non-equatorial backyard is megadiverse??
Not-green not-central limit Davey – hopeless.
Too much soft gooey systems and Earl Grey.
PACE of CHANGE ! Davey – not evolutionary – think 50-100 years.
Davey reach behind ears – turn switch to “on”.
This paper isn’t proof of anything – there’s a lot more been going on over the past 520 million years than just warming or cooling.
Luke,
Once more you have made a complete public donkey of yourself, in your narcissistic attempt to ridicule someone else.
Notwithstanding deserts and mountain tops, I believe there is a generally declining terrestrial species richness gradient from equator to poles. Think of the Amazon Basin to Tierra del Fuego.
Temperate heaths in southern Africa and Australia are anomalously rich (botanically) due to long past human intervention with mosaic fire. A vacant third rate computer geek like you would not understand that. Go back to mechanistic Fortran programs. They may give you the sense of power you obviously crave, and are unsuccessfully seeking through ridicule, and eco-warrior posturing. I’ll bet you chew your fingernails and have bad breath. Your testicles are the size of sparrow eggs, probably one is undescended – now who else was like that? Anyway, I fart in your general direction.
P.S. Significant evolutionary change can take place in decades – think of Pepper Moths and the Industrial Revolution. Too difficult for Luke Schicklegruber? Reach behind ear and switch to ‘zip gob’.(Come in, SJT)
Davey – well abused. High marks.
But you miss the main point – it’s the pace of change and atmospheric circulation changes. I just added a few exceptions to annoy you.
Aren’t generalities a worry. Are Australian savannas that diverse – nice & warm ? What’s the diversity of a temperate Tassy rainforest or a nice NZ rainforest. How diverse is a Tierra del Fuegan Nothofagus forest.
P.S. Fyuk you. Nah only kidding.
P.P.S. Have you been peeking at my gonads again? Your profiling is really spot on. Finger nails too.
Wonder how those temperature dependent flora on Bartle Frere will go ?
“9 billion people all potentially impacted by climate” Posted by: Luke at October 25, 2007 09:29 AM
World Population: 6,602,224,175 (July 2007 est.)
What’s a billion or two this way or that when in the service of a higher truth?
“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”.
The authors of these sentences are incompetent.
The first sentence is a non sequitur, and basically incomphrensible.
But Luke and Anthony seem well equipped to explain it.
Yep chrisgo – wrong digit – it’s 6B but same import.
Luke is getting a hammering on this one. He will switch to other threads. Where’s SJT?
Dirty Brown Davey, the ever present fence sitter, is becoming a bit of a serial mofo.
Give up Luke,
Your ranting and abuse have lost you all credibility and respect. It must be the gamma rays from the computer screen. Ask BoM to redeploy you, far from computers. Groundsman perhaps, or handyman?