Following the review of Avatar, with its message of respect for the world and living beings that surround us, here’s a very sad report of what we’re doing to our own Gaia here on Earth:
Eight years ago, world governments made a pledge to put a halt to growing biodiversity loss by 2010. They have not succeeded. The ongoing loss of biodiversity has instead become even more severe of a threat to the planet's once-balanced ecosystems--it's become a full-on extinction crisis. Thanks to human development and expansion, species are now going extinct exponentially faster than ever before--they're dying out at the frightening speed of 1,000 times the natural rate.
This has lead many to term the current period of biodiversity loss 'the sixth great extinction'--but instead of a natural event like an asteroid impact, this one is being caused by the development of human infrastructure, and the expansion of farming and of cities. With the worldwide population surging, biodiversity in sensitive areas like the Amazon and the Indonesian islands--and just about everywhere else--is suffering as deforestation occurs in more and more new frontiers.
[A]s natural systems such as forests and wetlands disappear, humanity loses the services they currently provide for free, such as the purification of air and water, protection from extreme weather events and the provision of materials for shelter and fire.
Aren’t those things all worth fighting for, rather than against?
The study of the fossil and archaeological record over the past 30 million years by UC Berkeley and Penn State University researchers shows that between 15 and 42 percent of the mammals in North America disappeared after humans arrived.
That means North American mammals are well on the way - perhaps as much as half way - to a level of extinction comparable to other epic die-offs, like the one that wiped out the dinosaurs.
The analysis by Barnosky, research associate Marc Carrasco and Penn State's Russell Graham was published this week in the scientific journal PLoS ONE. It compares the extinctions of mammals in North America after humans arrived 13,000 years ago to the five mass extinctions on Earth over the past 450 million years.
The least severe of those extinctions wiped out the dinosaurs 68 million years ago and killed off 75 percent of the species on the planet.
Although humans clearly did not have anything to do with the previous extinctions, many scientists are afraid that global warming and other environmental problems caused by the ever-increasing human population could have similarly catastrophic consequences.
Previous research has shown that most mammal extinctions in North America, Australia, Europe and Northern Asia have occurred within a few thousand years after the arrival of humans. This study puts that data into historical perspective, providing the percentage of animals that went extinct during certain time periods compared with other epochs.
Humans reached North America about 13,000 years ago and more than 50 species disappeared over the next 2,000 years, including mammoths, saber-toothed cats, giant ground sloths and other large animals, according to the study.
The arrival of humans coincided with the end of the last ice age, but the study pointed out that 38 other ice ages had occurred in North America over the past 2 million years and there were no comparable die-offs during the others.
"The only difference is that 13,000 years ago, humans appear on the scene," Carrasco said. "The bottom line is, mammals in general were able to deal with these changes in the past. Only when humans arrive do the numbers fall off a cliff."
Sad. Very sad indeed.
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