Angkor at that time faced a number of problems—social, political and cultural. Environmental change pushed the ancient Khmers to the limit and they weren’t able to adapt said the study’s lead author, Brendan Buckley, a climate scientist and tree-ring specialist at Columbia University Lamont-Doherty Earth Observatory.I wouldn’t say climate caused the collapse, but a 30-year drought had to have had an impact.

Scientists led by Buckley were able to reconstruct 759 years of past climate in the region surrounding Angkor by studying the annual growth rings of a cypress tree, Fokienia hodginsii, growing in the highlands of Vietnam’s Bidoup Nui Ba National Park, about 700 kilometers away. By hiking high into the mountain cloud forests, the researchers were able to find rare specimens over 1,000 years old that had not been touched by loggers. After extracting tiny cores of wood showing the trees’ annual growth rings, researchers reconstructed year-to-year moisture levels in this part of Southeast Asia from 1250 to 2008. The tree rings revealed evidence of a mega-drought lasting three decades—from the 1330s to 1360s-- followed by a more severe but shorter drought from the 1400s to 1420s. Written records corroborate the latter drought, which may have been felt as far away as Sri Lanka and central China.

The droughts may have been devastating for a civilization dependent on farming and reservoirs, canals and embankments sprawling across more than a thousand square kilometers. The droughts could have led to crop failure and a rise in infectious disease, and both problems would have been exacerbated by the density of the population, Buckley says.

The study also finds that the droughts were punctuated by several extraordinarily intense rainy seasons that may have damaged Angkor’s hydraulic system. During a normal monsoon season, Angkor’s hydraulic network could have handled heavy downpours, but after extended droughts, the system may have been vulnerable to massive siltation and clogging, the study suggests. Layers of coarse debris and other sediments found blocking some canals appear to have been laid down suddenly. In other spots, apparently sudden erosion cut canals as much as 8 meters below the surrounding landscape, potentially destabilizing the hydraulic system. Archeologists have found additional evidence that canals were rebuilt and rerouted to cope with water shortages.

http://www.sciencedaily.com/reales/2010/03/100329203547

Monday, May 3, 2010

Heey

Hi everybody! Enjoy reading this blogg =)
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5 comments:

  1. Blake BarkerMay 5, 2010 at 8:27 AM

    Global Warming is a very big issue but i dont think there is a ton people can do to change the fact that what we have done to the climate can not be put back to normal and global warminmg will keep becoming more and more of an issue on earth.

    ReplyDelete
  2. dsushkoMay 5, 2010 at 8:40 AM

    we will have a lot of big trouble if we won't do anything, many animals will die...

    ReplyDelete
  3. cbierfeldtMay 13, 2010 at 8:52 AM

    Is global warming really all its cracked up to be or has the media blown it out of proportion? Historical data shows that global warming is cyclic and extinction of species is a natural process. Change is inevitable and species of animals must adapt pr die...it sounds harsh but it is a fact of life. I would like to hear your comments on this side of the global warming issue...I would also like to see a link or two to an article(s) that support this flip side.

    ReplyDelete
  4. Blake BarkerMay 17, 2010 at 7:41 AM

    I would be more worried about humans than animals even though we do need animals. Global warming is happending and all we can do is find away to prevent it or try.

    ReplyDelete
  5. UnknownOctober 3, 2020 at 11:46 PM

    Now our planet is going through hard times. People are to blame for this. Few companies like https://aduk.de/services/machine-vision/ are involved in recycling, landscaping or solar panels.

    ReplyDelete

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Climate influence on Human Evolution
Some Record documents a history of critical evolutionary events that have ultimately shaped and defined what it means to be human, including the origins of bipedalism; the emergence of our genus Homo; the first use of stone tools; increases in brain size; and the emergence of Homo sapiens, tools, and culture. The Earth's geological record suggests that some evolutionary events were coincident with substantial changes in African and Eurasian climate, raising the possibility that critical junctures in human evolution and behavioral development may have been affected by the environmental characteristics of the areas where hominins evolved. Understanding Climate's Change on Human Evolution explores the opportunities of using scientific research to improve our understanding of how climate may have helped shape our species.

http://www.nap.edu/catalog.php?record_id=12825


Global Warming

Global warming is the increase of the Earth's average temperature since the mid-20th century. Global warming may become a problem for the world and has already been linked to floods and other types of storms. Today, the atmosphere of the world is about a half a degree Celsius warmer than it was two hundred years ago. Many people want to know why the Earth's climate is changing. Most say that the changes are caused by people (by cars and factories, for example). Some say the change is not the fault of humans. The average temperature at the surface of the Earth has gone up by 0.6 Celsius since the late 19th century. There are several theories (ways) which try to explain this increase. Most scientists think that the warming of the last 50 years is believed to be a result of increases in the greenhouse effect caused by human-generated carbon dioxide (CO2). A few think that changes are because of differences in the amount of heat from the sun and other natural causes. A "theory" in science is not just an idea. It is a proposed answer which has been tested and agreed on by many scientists, yet has not been confirmed as a actual objective of existence, and is in debate. Climate theories are hard to test because they usually depend on computer models, which are themselves theories. Today, most climatologists agree that the theory of anthropogenic global warming has survived challenges and testing against data from many sources. Anthropogenic global warming is a better "fit" to what scientists see in the data. Climate models show that temperatures will probably increase by between 1.4 °C and 5.8 °C from 1990 to 2100. Much of the uncertainty in this increase is from not knowing how much CO2 and other greenhouse gasses cars, factories and other polluters will put into the air. There is also some doubt in some details of the climate models. Climate commitment studies predict that even if levels of greenhouse gases were to stay the same, the temperature would still increase by 0.5 °C over the next one hundred years. This is because of the gasses that people have already put into the atmosphere.
http://en.wikipedia.org/wiki/Global_warming