Drop Down MenusCSS Drop Down MenuPure CSS Dropdown Menu

Friday, March 23, 2012

Humans and Climate, Source of The Extinction Disaster

Research team of British scientists thrusting new findings about what caused the extinction of most of the big beasts of the earth during the last 100 thousand years. The research team of University of Cambridge in England suggests that human hunting and climate change is causing a wave of mega fauna extinctions in the past, such as mammoths and mastodons from the earth. 
The wooly mammoths may have succumbed to a combination of rapid climate change and human depredation, possibly by overhunting. (Picture from: http://news.sciencemag.org/)
By conducting an assessment of extinction during the late Quaternary period, from 700 thousand years ago until now, especially the last 100 thousand years, the researchers can estimate the relative value of a number of different factors that cause the extinction of large terrestrial animals (the animals weigh more than 44 kgs.)

Researchers used data from Antarctic ice cores that record the Earth's climate changes since a few hundred thousand years ago. They also compiled information Happenings arrival of humans from Africa into five major mainland, namely North America, South America, most of Eurasia, Australia and New Zealand.
The American mastodon rendering. (Picture from: http://commons.wikimedia.org/)
Statistical analysis showed that the combination of the arrival of humans and climate change caused the extinction. The research results also provide input for the consequences of the pressures on large animals living today, such as tigers, polar bears, elephants, and rhinos.

Graham Prescott, currently a PhD student at the University of Cambridge and co-author on the paper, highlighted how their research may inform us about the current plight facing large animals: "Our research suggests that a combination of human pressure and climate change was able to cause the extinctions of many large animals in the past. Many large, charismatic animals today are threatened by both hunting pressure and changes in climate; if we do not take action to address these issues we may see further extinctions. And in contrast to the people who first encountered these megafauna, people today are fully aware of the consequences of our actions; this gives us hope that we can prevent future extinctions, but will make it all the worse if we do not."

David Williams, currently a PhD student at the University of Cambridge and co-author on the paper, added: "The loss of these animals has been a zoological puzzle since the time of Charles Darwin and Alfred Russel Wallace. At that time, many people didn't believe that human-caused extinctions were possible, but Wallace argued otherwise. We have now shown, 100 years later, that he was right, and that humans, combined with climate change have been affecting other species for tens of thousands of years and continue to do so. Hopefully, now though, we are in a position to do something about it."

Professor Rhys Green, an author on the paper from the University of Cambridge and the Royal Society for the Protection of Birds (RSPB) said: "Most previous studies have argued that the extinction of mammoths and other megafauna is linked separately to either human pressure or climatic change. Our work indicates that they had their devastating effect working together. This previous combination of unusual patterns of climate change and direct human pressure from hunting and habitat destruction is similar to those to which we are subjecting nature to today and what happened before should be taken as a warning. The key difference this time is that the climate change is not caused by fluctuations in the earth's rotation axis but to warming caused by fossil fuel burning and deforestation by humans – a double whammy of our own making. We should learn the lesson and act urgently to moderate both types of impact." *** [SCIENCEDAILY | KORAN TEMPO 3815]
Note: This blog can be accessed via your smart phoneEnhanced by Zemanta
Kindly Bookmark and Share it: