Saturday, 17 November 2012

An Ice Age is coming - only C02 can save us

A group of Swedish scientists at the University of Gothenburg have published a paper in which they argue that spreading peatlands are inexorably driving planet Earth into its next ice age, and the only thing holding back catastrophe is humanity's hotly debated atmospheric carbon emissions.
"We are probably entering a new ice age right now. However, we're not noticing it due to the effects of carbon dioxide," says Professor of Physical Geography. Lars Franzén, from the Department of Earth Sciences at GothenburgUniversity.
Peatlands grow in height and spread across their surroundings by waterlogging woodlands. They are also one of the biggest terrestrial sinks of atmospheric carbon dioxide. Each year, around 20 grams of carbon are absorbed by every square metre of peatland.
The scientists have calculated that the potential is there for Swedish peatlands to triple in extent, enormously increasing their carbon sink effect. By extrapolating to include the rest of the world's high-latitude temperate areas - the parts of the globe where peatland can expand as it does in Sweden - they project the creation of an extremely powerful carbon sink. They theorise that this is the mechanism which tends to force the Earth back into prolonged ice ages after each relatively brief "interglacial" warm period. Carbon sequestration in peatland may be one of the main reasons why ice age conditions have occurred time after time.
With no other factors in play, the time is about right for the present interglacial to end and the next ice age to come on. Indeed, Franzén and his crew think it has barely been staved off by human activity. The researchers believe that the Little Ice Age of the 16th to 18th centuries may have been halted as a result of human activity. Increased felling of woodlands and growing areas of agricultural land, combined with the early stages of industrialisation, resulted in increased emissions of carbon dioxide which probably slowed down, or even reversed, the cooling trend.
Other scientists have attributed the Little Ice Age to a quiet period in the Sun's activity: others say it was purely a local effect in Europe.
Thus, on a global scale, carbon sequestration in peatlands may have had important climate cooling effects towards the ends of previous interglacials ... It cannot be ruled out that similar effects would be seen in a hypothetical Holocene lacking human presence.
It's probably worth noting that the great physicist Freeman Dyson long ago suggested that only relatively small amounts of new peatland would be enough to sequestrate colossal amounts of CO2 from the air. Other scientists have noted in recent times that brief warming spells like that observed at the end of the 20th century appear to have occurred towards the end of previous interglacial periods - just before the glaciers returned.
If Franzén and his team are right, the big chill is now under way, and is only just being held off by increasing human carbon emissions - perhaps explaining why temperatures have been merely flat for the last 15 years or so, rather than descending.

Tuesday, 13 November 2012

Dec 6th - Eight Evolutionary Myths: the closing of the Darwinian mind?

Eight Evolutionary Myths: the closing of the Darwinian mind?
Professor Simon Conway-Morris, F.R.S., Department of Earth Sciences, University of Cambridge
Prof. Conway-Morris’ focus of research concerns the study of the constraints on evolution, and the historical processes that lead to the emergence of complexity, especially with respect to the construction of the major animal bodyplans in the Cambrian explosion. His work is central to palaeobiology, but is also of great interest to biologists and bioastronomers, as well as the wider community.
Click here to read 'Rethinking Evolution'
BRLSI, 16 Queen Square, Bath, 7.30 p.m. 6th December
Everyone is welcome - visitors £4 - free refreshments

Nov 16th - Visit to Moon's Hill Quarry and Somerset Earth Science Centre

Bath Geological Society is organising a visit to this quarry on November 16th. There are two places still available.
Please contact our field secretary - email or tel. 07712776117.

Friday, 26 October 2012

Fossil Rock Anthem

What do you think of this?
 

Limbed Fish

Recent discoveries of advanced fish-like stem-tetrapods (for example, Panderichthys and Tiktaalik) have greatly improved our knowledge of the fin-to-limb transition. However, a paucity of fossil data from primitive finned tetrapods prevents profound understanding of the acquisition sequence of tetrapod characters. However, a new stem-tetrapod (Tungsenia paradoxa gen. et sp. nov.) from the Lower Devonian (Pragian, ~409 million years ago) of China, extends the earliest record of tetrapods by some 10 million years. Sharing many primitive features with stem-lungfishes, the new taxon further fills in the morphological gap between tetrapods and lungfishes. The X-ray tomography study of the skull (photo) depicts the plesiomorphic condition of the brain in the tetrapods. The enlargement of the cerebral hemispheres and the possible presence of the pars tuberalis in this stem-tetrapod indicate that some important brain modifications related to terrestrial life had occurred at the beginning of the tetrapod evolution, much earlier than previously thought.