global warming linked to the Plague http://news.bbc.co.uk/1/hi/sci/tech/4755328.stm Europe's "Little Ice Age" may have been triggered by the 14th Century Black Death plague, according to a new study. Pollen and leaf data support the idea that millions of trees sprang up on abandoned farmland, soaking up carbon dioxide from the atmosphere. This would have had the effect of cooling the climate, a team from Utrecht University, Netherlands, says. The Little Ice Age was a period of some 300 years when Europe experienced a dip in average temperatures. Dr Thomas van Hoof and his colleagues studied pollen grains and leaf remains collected from lake-bed sediments in the southeast Netherlands. Monitoring the ups and downs in abundance of cereal pollen (like buckwheat) and tree pollen (like birch and oak) enabled them to estimate changes in land-use between AD 1000 and 1500. Pore clues The team found an increase in cereal pollen from 1200 onwards (reflecting agricultural expansion), followed by a sudden dive around 1347, linked to the agricultural crisis caused by the arrival of the Black Death, most probably a bacterial disease spread by rat fleas. This bubonic plague is said to have wiped out over a third of Europe's population. Counting stomata (pores) on ancient oak leaves provided van Hoof's team with a measure of the fluctuations in atmospheric carbon dioxide for the same period. This is because leaves absorb carbon dioxide through their stomata, and their density varies as carbon dioxide goes up and down. "Between AD 1200 to 1300, we see a decrease in stomata and a sharp rise in atmospheric carbon dioxide, due to deforestation we think," says Dr van Hoof, whose findings are published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology. But after AD 1350, the team found the pattern reversed, suggesting that atmospheric carbon dioxide fell, perhaps due to reforestation following the plague. The researchers think that this drop in carbon dioxide levels could help to explain a cooling in the climate over the following centuries. Ocean damper From around 1500, Europe appears to have been gripped by a chill lasting some 300 years. There are many theories as to what caused these bitter years, but popular ideas include a decrease in solar activity, an increase in volcanic activity or a change in ocean circulation. The new data adds weight to the theory that the Black Death could have played a pivotal role. Not everyone is convinced, however. Dr Tim Lenton, an environmental scientist from the University of East Anglia, UK, said: "It is a nice study and the carbon dioxide changes could certainly be a contributory factor, but I think they are too modest to explain all the climate change seen." And Professor Richard Houghton, a climate expert from Woods Hole Research Center in Massachusetts, US, believes that the oceans would have compensated for the change. "The atmosphere is in equilibrium with the ocean and this tends to dampen or offset small changes in terrestrial carbon uptake," he explained. Nonetheless, the new findings are likely to cause a stir. "It appears that the human impact on the environment started much earlier than the industrial revolution," said Dr van Hoof. seems like they are implying that the current issues about global warming are infact the planet making a recovery from this 'mini ice age'
very interesting, although there is considerable evidence that humans are impacting global warming. but it is also believed the planet goes through cycles of warming and cooling (eg ice ages). still while im sure the planet does have natural periods of warming and cooling that impact the carbon cycle, the human impacts on the planet in recent history is bound to affect any future temperature changes.
some canny evidence to back up his theories, but i still reckon we are THE major benifactor in whats goin on with the environment
aye, the hole in the ozone is there to see... i'll give us til 2020 before we see how much trouble we're really in.
from what ive been reading recently we're gonna have serious problems well before we cark it... unlesss we can get a clean source of energy, hydrogen is an option but its not viable as yet.
the brazilians run 80% (give or take) of there cars on alcohol,,and take shed loads of the power via hydro-electricity, it is the way forward its all about the coin though, renewable alternatives take £££ to set up, suppose its worth it when u consider what will happen to this place,, sayin that IF it all goes pair shaped, i have read som canny articles totally discounting human involvment in global warming, but personally i think we are fucked
you can run a car on electricity, its just who's gonna turn round to the big car companies and force a change? its all politics and beauracracy and this country is one of the worst. there's a continued growth in energy demand and a continued growth in transport as well as other sectors. the EU estimates 70% of energy supplies will be imported from unstable areas by 2030, although it could be sooner by now. EU energy growth is expected to be at 0.4% per annum until 2030, might not sound like much but on that timescale its highly dangerous. EU carbon levels expected to be 18% higher than 1990 level by 2030 plus fossil fuels accounting for 90% of supplies in 2030. the only way to help change the scenario is by either using less energy by increasing efficiency which will impact on our lifestyles, or by changing to a low/no carbon energy source. being efficient can be misleading as there are theories about the "rebound effect", micro level savings lead to macro level increases. however if we built houses in this country to the standard they do in sweden then the need for external heating would be minimum... the swedes build so well that even in their climate a house can be heated by lightbulbs and body heat, sounds crazy but its how well controlled their construction is compared to ours, its light years ahead. also japan and australia do a 'top runner' scheme where by only the most efficient appliances are on the market, for example, if a company deleops a better energy efficient washing machine then the rest of the industry has a couple of years to catch up... it raises standards and competativeness. over here we have the eco-labelling but you can still go out and but a crappy cheap appliance that eats up energy, its bizarre considering we should be trying to save as much as we can.
