Thursday, October 1, 2009

Our Planet without Humans

As I was looking around, trying to find relevant articles for our discussion on carbon cycles, I came across one by Bob Holmes (found here: This articles takes a worst-case-scenario look at how global warming could violently affect "carbon-rich peat locked in permafrost". In Holmes' catastrophic scenario, "As the Arctic warms, the peat could decompose and release trillions of tonnes of carbon into the atmosphere - perhaps exceeding the 3 trillion tonnes that humans could conceivable emit from fossil fuels."

This could then kick off a monumental greenhouse gas effect that would drastically raise the temperature of Earth's atmosphere. According to some conservation biologists, this may then lead to "one of the greatest mass extinctions ever - one that would alter the trajectory of evolution."

While sharp spikes in Earth's atmosphere are far from unprecedented, within the history of our planet, this one could be very different. During the Palaeocene-Eocene thermal maximum, which saw an increase of 9 °C, living species were able to merely migrate to areas of the planet with more suitable living conditions. Now, however, with the irreversible changes humans have made to the planet, by building cities, highways etc., such migration is unrealistic.

On top of the destruction of natural habitats we've caused, we've also created a "perfect storm as far as biodiversity is concerned", says David Jablonski. According to Jablonski, "We're not just overhunting and overfishing. We're not just changing the chemistry of the atmosphere and acidifying the oceans. We're not just taking the large-bodied animals. We're doing all this stuff simultaneously."

After the possible mass extinction, the article goes on to say that it would be a fairly random selection of plants and animals that would survive. There is some good news, however. Sort of. While the Earth would, over the course of many millions of years, probably experience a rebound of living species, humans, almost certainly would not be a part of it.

In the last line of his article, Holmes remarks that "even if we manage to overpopulate and overconsume ourselves back to the Stone Age, the Earth will probably survive. Life will go on." So here is one of the possible results of the damage we've done to our planet: the Earth will go on, but it will do so without us.

1 comment:

  1. and that would also throw 2 million years of homo sapiens evolution down the drain.

    Its really too bad you can't transfer all that peat to Mars and burn it all- Mars could use a few degrees Celsius lift in order to sustain human life. I've read 0 celsius is a warm day over there.

    oh, and the fact that humans will not be living in that scenario's aftermath is not "good news". We're trying to preserve our own species, if we're gone does it matter what happens afterwards?