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Selasa, Mac 26, 2013

Polar bears or teddy bears?

In 2006, the polar bear was officially declared and endangered species by the World Conservation Union. In the previous three or four years, the reality of human-induced global warning was accepted by most nations and their scientific academies. The connection between these two developments may not be obvious but whilst the loss of their hunting habitat and the threat to polar bears may be accepted by many ecologists, there is no proven link to climate change.

Here, in simple terms, are the likely connections between human-induced atmospheric warming and the threat to the polar bear:

  • Human being have been releasing fossilized carbon into the atmosphere.
  • Human numbers and activity have dramatically increased atmospheric carbon levels in the last 250 years.
  • High concentration of carbon in the atmosphere increase its greenhouse effect and its average temperature.
  • Higher global temperatures lead to melting of the Arctic ice sheets.
  • Reduced ice cover over the Arctic seas reduces the feeding  time for polar bears.
  • Polar bear reproduction and condition decline and their population sizes decrease.
It now becomes a question of which of the above statements is false, or which implied connection is not demonstrate and then what it would take to prove each statement or demonstrate the connection, either to a scientist or to a decision maker.

Perhaps polar bears will become a part of the price of our economic progress, though only a small part. Thin polar bears on thinner ice are symbolic of the danger facing the living biota of our planet, emblematic of the shrinking space we allow other species. The bears speak for us, and the demands our numbers place on the capacity of the earth. 

We should not expect rapid changes or wait for obvious shifts before we take decisions. Like the melting ice, the shifts in the climate will be gradual. It can only get hotter. The fire lit by homo erectus 3 million years ago is still burning. 

Who would have thought that one species, a clever ape, could threaten the existence of so many others? Who indeed?

By: first ecology, third edition, oxford.

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