Showing posts with label climate change. Show all posts
Showing posts with label climate change. Show all posts

Tuesday, October 27, 2009

Ice Age Mammoths Pass Far Below 40 Degrees North Latitude

Climate Events Let Ice Age Mammoths Pass Far Below 40 Degrees North Latitude

 Europe’s southern-most skeletal remains of Mammuthus primigenius were unearthed in a moor on the 37°N latitude. This is considerably south of the inhospitable habitat than one usually imagines for mammoths, and for the characteristically dry and cold climate that prevailed during the ice ages in the north of Eurasia.

The remains of the ice age giants from Padul were examined in a joint scientific project of four research institutions, namely, the Quaternary Paleontology arm of the Senckenberg Research Institutes of Germany, the Universities of Madrid and Oviedo in Spain, and the Natural History Museum of Rotterdam, the Netherlands.

"These woolly mammoths finds do not belong to stray animals who only chanced to head south, but belonged to Granada's permanent inhabitants at this time”, says Diego Álvarez-Lao from the University of Oviedo. Dick Mol, ice age expert at the Natural History Museum of Rotterdam adds: “Nevertheless, the Spanish mammoths have not differed anatomically from their congeners in more northern regions.”

Climate- and environmental data show that it was not the longing for summery temperatures or the chirp of crickets that lured the ice age giants to the south, but a diet of grass, various herbs and shrubs. The expansion of the mammoth steppe with its typical vegetation allowed the wandering of the giants and other ice age animals below the 40° N latitude and far to the south.

Nuria García from the University Complutense de Madrid explains: "Fossil plants which have been found in drill cores from scientific drilling in Spain and the nearby Mediterranean Sea, as well as our investigations of the Padul sediments indicate that the animals lived on the plants of the mammoth steppe.”

Among the discoverers of Europe's southern-most finds is Senckenberg scientist Ralf-Dietrich Kahlke, who focused on the reasons that Mammuthus primigenius passed below the 40°N latitude. “A comparison with other sites between the 38°N and 36°N latitude shows that the animals pushed south 30 to 40 thousand years ago also in areas outside of Europe”, the ice age paleontologist explains and demonstrates with maps. Thus the southern-most sites of the ice age giants lie on a belt which stretches from Western Europe via Georgia, the Siberian Baikal region to eastern China and from Korea till the Midwest of America.

Nevertheless the dispersal of the giants was blocked now and then. The impressively high Sierra Nevada at Padul formed a natural barrier. Likewise, the Rocky Mountains in North America had a similar effect. Other obstacles were areas that did not offer suitable food, as desert-like regions or the Grait Plains of North America which expanded on account of a vegetation change.

The present study documents for the first time the southerly push of Mammuthus primigenius in Europe and points out that their migration to southern Spain and Italy happened the same time as similar advances into eastern China, to the north of Japan and to Kamchatka. The team of scientists suggests that this phenomenon is related to coupled climate events in the northeast Atlantic and the northwest Pacific. Dr. Kahlke concludes: „This is proof that global mechanisms which regulated climate already during the ice age also influenced vegetation and with it also animal migration”.

Journal reference:
Álvarez-Lao et al. The Padul mammoth finds — On the southernmost record of Mammuthus primigenius in Europe and its southern spread during the Late Pleistocene. Palaeogeography Palaeoclimatology Palaeoecology, 2009; 278 (1-4): 57 DOI: 10.1016/j.palaeo.2009.04.011
Adapted from materials provided by Senckenberg Research Institute and Natural History Museum, via AlphaGalileo.

Sunday, October 11, 2009

Is Garbage The Solution To Tackling Climate Change?


Garbage dump. Waste-based biofuel could cut global emissions by over 80%. (Credit: iStockphoto/Ryerson Clark)
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Converting the rubbish that fills the world’s landfills into biofuel may be the answer to both the growing energy crisis and to tackling carbon emissions, claim scientists in Singapore and Switzerland. New research published in Global Change Biology: Bioenergy, reveals how replacing gasoline with biofuel from processed waste could cut global carbon emissions by 80%.

Biofuels produced from crops have proven controversial because they require an increase in crop production which has its own severe environmental costs. However, second-generation biofuels, such as cellulosic ethanol derived from processed urban waste, may offer dramatic emissions savings without the environmental catch.

“Our results suggest that fuel from processed waste biomass, such as paper and cardboard, is a promising clean energy solution,” said study author Associate Professor Hugh Tan of the National University of Singapore. “If developed fully this biofuel could simultaneously meet part of the world’s energy needs, while also combating carbon emissions and fossil fuel dependency.”

The team used the United Nation’s Human Development Index to estimate the generation of waste in 173 countries. This data was then coupled to the Earthtrends database to estimate the amount of gasoline consumed in those same countries.

The team found that 82.93 billion litres of cellulosic ethanol could be produced from the world’s landfill waste and that by substituting gasoline with the resulting biofuel, global carbon emissions could be cut by figures ranging from 29.2% to 86.1% for every unit of energy produced.

“If this technology continues to improve and mature these numbers are certain to increase,” concluded co-author Dr. Lian Pin Koh from ETH Zürich. “This could make cellulosic ethanol an important component of our renewable energy future.”


Journal reference:

  1. Shi et al. The biofuel potential of municipal solid waste. GCB Bioenergy, 2009; DOI: 10.1111/j.1757-1707.2009.01024.x
Adapted from materials provided by Wiley - Blackwell, via AlphaGalileo.