Climate Change and Extinctions

Climate change has already degraded conditions for many species, including people.

Climate change could carry off 20% to 30% of all species on Earth before the end of the century. In addition to our other activities, such as hunting and destruction of habitats, our greenhouse emissions have lead to nearly 1 in 4 mammals worldwide being at risk of extinction.

The Earth has experienced five waves of extinctions before, including the Cretaceous period 65 million years ago, which wiped out the dinosaurs, and the Permian extinction which vanquished 70% of all land animals and 96% of all marine creatures.

Scientists now say that we have entered a sixth extinction wave. The difference is, this time the cause is not a wayward asteroid or a mega-volcano. It’s us.

Life in the polar regions is undergoing substantial change due to melting ice and subsequently decreased habitat. Elsewhere, rising sea levels are damaging coastal wetlands and flooding deltas. Warmer ocean waters are bleaching coral reefs, forcing marine life toward the cooler poles, and decimating fish populations in inland lakes.

Conservationists estimate that extinctions are now up to 10,000 times as frequent than at any other time in human history. And this rate is likely accelerating because of factors including climate change.

So should we worry about the extinction of other species, when we our own species might be threatened? Well, for one thing, nobody knows exactly what other creatures do for us. Even the lowliest organism might be a key part of the food-chain that keeps a whole ecosystem up and running. The more species diversity in an ecosystem, the more resilient and productive it is for us.

That means, the more that climate change threatens other species, the more difficulties we might have with food production and other activities.

Animals and plants that might not seem that important to us, also act as a test for our own habitat. The same natural resources that sustain wildlife, such as clean water, unpolluted land and healthy forests, are ultimately the same things that we need to sustain ourselves.

So if climate change is creating the sixth mass extinction, could it also lead to our own?

References

Brian Walsh, ‘The New Age of Extinctions’, Time Magazine, 2 April 2009, http://www.time.com/time/specials/packages/article/0,28804,1888728_1888736_1888858,00.html

Kimberly Johnson, ‘One in Four Mammanls at Risk of Extinction’, National Geographic News, 6 October 2008, http://news.nationalgeographic.com.au/news/2008/10/081006-mammals-extinction.html

Brian Walsh, ‘The New Age of Extinctions’, Time Magazine, 2 April 2009, http://www.time.com/time/specials/packages/article/0,28804,1888728_1888736_1888858,00.html

The International Union for Conservation of Nature, ‘Species Extinction – the facts’, 2007, http://docs.google.com/viewer?a=v&q=cache:lmrTV79TEDwJ:cmsdata.iucn.org/downloads/species_extinction_05_2007.pdf+International+Union+for+the+Conservation+of+Nature+extinctions+are+1,000+times+as+frequent+human+history&hl=en&gl=au&pid=bl&srcid=ADGEEShwgDxaFoJLf7E_tSln8IeTuPutJnMvHL-oY7C-XvlHLtWaMTuE4HVEMOyqo6-fg6YVeTpYJHOmpvl4qqt3OTFWebfqEII_Jvo-k7RUEWIUMZQKc03xTiD53f8pPopwvQIASqrp&sig=AHIEtbTbm28hWS56_gkbXR3S81YeOPxTWg