The concept of ensuring we keep global temperature rises below 2 °C t is often quoted in the media. But that target—decided upon during international climate talks—may not be enough to save the planet's species.


In an article published in Climate Change Responses, Petra Tschakert of Penn State University in University Park writes that a 1.5 °C target would be far more appropriate. "Without a doubt, it is in the utmost interest of a large number of countries to pursue the 1.5°C target, as ambitious or idealistic it may appear to date, and to see it anchored as a binding goal..." she writes.

While the 2°C target was officially endorsed during the Copenhagen climate discussions in 2009, she points out that over two-thirds of the countries in the United Nations Framework Convention on Climate Change object to it. Those countries would instead prefer the target be 1.5°C.


As New Scientist points out, she's not alone in pushing for a revised target. During a climate conference in Lima, Peru, last year, Hans-Otto Pörtner from the Alfred Wegener Institute in Bremen argued that "some species would struggle to cope with the speed of 2 °C warming, but that most organisms should be able to move to a different place under 1.5 °C." A report from that conference is due in June and will potentially shape climate negotiations in Paris this December.

While many are arguing for a 1.5°C target, there will be opposition—not least because there's simply less research into the effects of such of a rise. Most studies have focused on what will happen to the planet if temperatures rise by 2°C. And at any rate, the planet has already warmed by 0.85 °C; topping out at 1.5°C seems ambitious at best and impossible at worst.

But for now, ambition is one of our best bets. Perhaps a 1.5°C isn't achievable—but as a target, it may help sharpen humankind's focus. [New Scientist]

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