Biological productivity controls cloud formation and may be the lever that caused supergreenhouse episodes during the Cretaceous and Eocene, according to Penn State paleoclimatologists.
“Our motivation was the inability of climate models to reproduce the climate of the supergreenhouse episodes of the Cretaceous and Eocene adequately,” said Lee R. Kump, professor of geosciences. “People have tried increasing carbon dioxide in the models to explain the warming, but there are limits to the amounts that can be added because the existing proxies for carbon dioxide do not show such large amounts.”
In general, the proxies indicate that the Cretaceous and Eocene atmosphere never exceeded four times the current carbon dioxide level, which is not enough for the models to create supergreenhouse conditions. Some researchers have tried increasing the amount of methane, another greenhouse gas, but there are no proxies for methane. Another approach is to assume that ocean currents changed, but while researchers can insert new current information into the models, they cannot get the models to create these ocean current scenarios.
Kump and David Pollard, senior research associate, Earth and Environmental Systems Institute, looked for another way to create a world where mean annual temperatures in the tropics were above 100 degrees Fahrenheit and polar temperatures were in the 50-degree Fahrenheit range. Changing the Earth’s albedo — the amount of sunlight reflected into space – by changing cloud cover will produce supergreenhouse events, the researchers report in today’s (April 11) issue of Science.
“The model reduces cloud cover from about 64 percent to 55 percent which lets in a large amount of direct sunlight,” Kump says. “The increased breaks in the clouds, fewer clouds and less reflective clouds produced the amount of warming we were looking for.”
EurekAlert: Absence of clouds caused pre-human supergreenhouse periods
National Geographic: Lack of Clouds Amplified Dino-Era Warming, Study Says
Amplification of Cretaceous Warmth by Biological Cloud Feedbacks
Lee R. Kump1* and David Pollard2
The extreme warmth of particular intervals of geologic history cannot be simulated with climate models, which are constrained by the geologic proxy record to relatively modest increases in atmospheric carbon dioxide levels. Recent recognition that biological productivity controls the abundance of cloud condensation nuclei (CCN) in the unpolluted atmosphere provides a solution to this problem. Our climate simulations show that reduced biological productivity (low CCN abundance) provides a substantial amplification of CO2-induced warming by reducing cloud lifetimes and reflectivity. If the stress of elevated temperatures did indeed suppress marine and terrestrial ecosystems during these times, this long-standing climate enigma may be solved.
1 Department of Geosciences and Earth System Science Center, Pennsylvania State University, University Park, PA 16802, USA.
2 Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA 16802, USA.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
The Cretaceous period is also hallmarked as being one of the most extensive kimberlite volcanism events during earth’s history.
Kimberlites are not normal volcanoes by any stretch of the imagination but are eruptions of CO2 charged, fluidised upper mantle magmas. They are associated with enormous quantities of CO2, and it is this carbon association that results in some klimberlites having economic quantities of diamonds. Diamond is the stable carbon phase in the upper mantle.
No one has witnessed any kimberlite eruption, and clearly there are no proxies for them either, so it isn’t surprising that climate models have problems working out where the extra CO2 might have come from.
What is of more interest are the forces that initiated the Cretaceous kimberlite eruptions and plate tectonics is totally unable to explain it. One hypothesis published recently in the NCGT Newsletter by a Russian Scientist suggests that kimberlite diatreme formation is caused by disruptions in the earth’s electrical field by close encounters with other space objects; here the Lamgmuir sheaf surrounding the earth is temporarily disrupted to cause subcrustal electrical stresses that initiate the kimberlite melts.
Kimberlite eruptions are essentially geological catastrophes which occur within a time-span of days. One can guess what would happen to the biosphere during those eruptions.
And it has nothing to do with a Greenhouse effect.
Reference to the NCGT Issue is http://www.ncgt.org/newsletter.php?action=download&id=49
Issue No 43, Paper “The Geological Consequences of large meteoric bodies approaching the earth” by Konstantin K. KHAZANOVITCH-WULFF.
In addition, spelling errors above, Klimberlites should be kimberlite, and it is Langmuir Sheaf, not Lamgmuir.
Kowtows appropriately.
And further more I wonder if the Cape Grimm station has these data on record 🙂
Louis: An essential tool in tracking climate change is sea level.
When I say sea level in the Cape Grim region is rising, how would your extra terrestrial bodies account for the present increase in the rate of SL rise? Answer ever so slowly hey.
Gavin,
Nothing at all to do with extra terrestrial bodies. Tasmania is sinking or sea levels are rising. Which do you prefer?
Louis: “Tasmania is sinking or sea levels are rising. Which do you prefer?”
Re plate tectonics, “Sea Levels to Plunge Long Term, Study of Dino Era Says”
http://news.nationalgeographic.com/news/2008/03/080306-sea-levels_2.html
Low CCNs ? see “The Revenge of Gaia”
Someone else can work out which comes first but today was quite cloudless and there was no haze anywhere on the horizon.
Gavin
have a browse at the NCGT web site where there are a large number of peer reviewed scientific papers showing plate tectonics to be wrong, and interestingly Plate Tectonics was developed by the same mind-set which developed agw – both are end products of the deductive method unrestrained by the compulsion of empirical fact.
Sea levels to plunge? This means a drop in sea levels.
Actually your post is a pretty good example of a non sequitur.
Beginning with the posted article, this may be the the biggest collection of non sequiturs in history.
Paul,
This would appear to fit very neatly with work by both Roy Spencer (ex NSAS, now University of Albama, Huntsville) and also the work at the Danish Space Research Institute on Cosmic Rays.
Thanks so much for posting this! 🙂
Jen
So it comes down to biology once again.
Where is the biology in the current GCM’s? The only reason we have a planet with a 20% free oxygen atmosphere is because of biology and the oceans are just full of biology on all scales, particularly micro. When this gets modeled convincingly I’ll start believing in coupled atmosphere – ocean models as anything other than means of understanding relatively crude and simple physical processes.
Apart from that, reading the abstract leads me to believe that the paper is more speculative BS. Whoopee! Fewer clouds means higher temperatures. Astounding!
*if* higher temperatures depress biological activity when there is more CO2, then there might be fewer clouds in the “unpolluted” atmosphere leading to higher temperatures.
So the atmosphere was “unpolluted”. You think this likely Louis Hissink?
Why should more warmth and CO2 depress biological activity? Most of it is surely of the micro kind with rapid adaptation and I would think the bugs would like more warmth and CO2.
We aren’t suffering from too much CO2, just too may “scientists” not do anything useful.
Not only does Gavin’s claim of sea level rise at Gape Grim seem to be off topic, it seems just a tall tale from his memory of warmer days in NW Tasmania looking west to Africa and South America. Cape Grim is said to have the cleanest air in the world due its 40 degree south location and no industrialized land mass within cooee. It is now the site of the Cape Grim Baseline Air Pollution Station (BOM CSIRO) that began taking samples of the atmosphere over twenty years ago.
For long term Sea-level measurements based in Tasmania you need to go to the South East and the early colonial tide gauge at Port Arthur convict settlement. These records suggest an average rate of sea-level rise of 0.8 mm/year ± 0.2 mm/year relative to the land in south-eastern Tasmania during the period 1841 to 2002.
This represents a lower rate than that observed elsewhere in the Australia/New Zealand region.
Eyrie
I don’t regard CO2 as a pollutant and as I pointed out on the Henry Thornton site recently, the observed, albeit it slight, drop in CO2 in the atmosphere does fit the geological evidence – that CO2 lags temperature. Tom Segalstad mentioned 5 years, so given the temperature record since 1998, it is to expected thath atmospheric CO2 will start dropping and soaked up by the oceans.
Now to wait until those who have linked clouds with “cosmic rays” realise that cosmic rays can also be known as electricity (charged particles in motion).
Have any of you noticed? You’re now quoting climate models !? and of the Cretaceous and Eocene – no hypocrisy here. Wow …
Luke, yes and I still do not quote climate modelling, so I think you had better be a little more selective in your tar-brushing.
As for the inane non sequitur “Cretaceous and Eocence – no hyporcrisy here.” be a little more specific so that you post evolves from being a simple soliloqy.
“What they found was that the clouds were less bright and that there were also fewer clouds. If they lowered the production of biogenic CCNs too much, their model created a world with remarkable warming inconsistent with life. However, they could alter the productivity in the model to recreate the temperature regime during supergreenhouse events” Hmmm, we continue to ignore the obvious.
Sea Level for dummies, no models required:
1st step; get into tide gauges
2nd step; read up on the IOC reports.
3rd step; follow the Roger Revelle Lectures.
This is purely an attempt to get blog climate debate back to a common boundary that can easily be observed by anyone at any point. While tides are moving all over the place so are temperature, cloud cover and rainfall, all very confusing hey.
I’m now going to claim that tide movement is probably the easiest of all variations to remove from old data and sea level thus becomes the best indicator of other climate trends like temperature, cloudiness and CO2 relative to life now.
Sure; we can include paleoclimate studies too provided they can be related to SL.
Up to date PSMSL Permanent Service for Mean Sea Level
http://www.pol.ac.uk/psmsl/
“Global Sea Levels: Past Present and Future” by John Church
http://www.gloss-sealevel.org/extlink/http%3A//unesdoc.unesco.org/images/0015/001561/156135E.pdf
“Sea Level Rise – Understanding the past – Improving projections for the future”
http://www.cmar.csiro.au/sealevel/sl_data_cmar.html
Gavin is the metamorphosis of Luke, an example of inverted evolution in which stupider is, is stupider will.
Not still flogging Church are we Gavin? Church of the “hindcast” from limited data? The same Church who claimed that 1990s sea level increases were much greater than the long term trend but failed to mention that the same could be said about seven other rising trends since the 1930s? The same Church who failed to mention that each of these past decadal rises was matched by a commensurate decadal decline where the decline was substantially at variance with the long term trend? The same Church who picked out 12 isolated, possibly sinking, mid-pacific tide stations while ignoring the far more stable stations with much longer data sets all along the East coast of Australia?
Once again, Gavin, you display all the intellectual rigour of a fart burn-off.
Reckon the burnoff hit a nerve close to the blog thinking cap
Penn State, AKA ‘Linebacker U’. Has anything good ever come from Happy Valley? Definitely nought but third-tier Big Ten science.
Paul, did the authors consider the arrangement of the continents in the Cretaceous? A big part of why this present period is so cold is due to the arrangement of continents (specifically Antarctica at the pole and surrounded by water, and the closure of the isthmus of Panama).
Lack of ice feedback makes it warmer.
Also the presence of enormous deserts in the Cretaceous may have helped lower the cloud levels.
Mt T makes an interesting comment but as is fast becoming obvious, plate tectonics, being not based in fact implies also that continental drift could not have happened in the past either, so the positions of the continents in the past, while climatically right, cannot have moved from there by surficial movement.
The only plausible mechanism is that of a tippe-toppe earth where, for various reasons, the earth seems have careened as proposed by Auchincloss-Brown, for example.
And let’s not bother with the furphy of inertial mass – electromagnetic interactions between the earth and another cosmic body, whatever it may be, can generate forces which could easily alter the earth’s axis of spin to that what was once a polar area could become equatorial.