Sunday, August 07, 2016

Scientists Warn World Will Miss Key Climate Target

Grim backdrop to vital global emissions talks as new analysis shows 1.5C limit on warming is close to being broken 

A tropical coral reef off Fiji. (Photograph Credit: Alamy) Click to Enlarge.
Leading climate scientists have warned that the Earth is perilously close to breaking through a 1.5C upper limit for global warming, only eight months after the target was set.

The decision to try to limit warming to 1.5C, measured in relation to pre-industrial temperatures, was the headline outcome of the Paris climate negotiations last December.  The talks were hailed as a major success by scientists and campaigners, who claimed that, by setting the target, desertification, heatwaves, widespread flooding and other global warming impacts could be avoided.

However, figures – based on Met Office data – prepared by meteorologist Ed Hawkins of Reading University show that average global temperatures were already more than 1C above pre-industrial levels for every month except one over the past year and peaked at +1.38C in February and March.  Keeping within the 1.5C limit will be extremely difficult, say scientists, given these rises.

These alarming figures will form the backdrop to the Intergovernmental Panel on Climate Change talks in Geneva this month, when scientists will start to outline ways to implement the climate goals set in Paris.  Dates for abandoning all coal-burning power stations and halting the use of combustion engines across the globe – possibly within 15 years – are likely to be set.
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Stanford University’s Professor Chris Field, co-chair of the IPCC working group on adaptation to climate change, told the Observer:  “From the perspective of my research I would say the 1.5C goal now looks impossible or at the very least, a very, very difficult task.  We should be under no illusions about the task we face.”

The Paris summit first agreed to limit global warming to 2C above pre-industrial levels and then decided to try to keep it below 1.5C.  This latter limit was set because it offered the planet a better chance of staving off catastrophes such as the melting of polar ice, which would no longer be able to deflect solar radiation and allow even greater global warming.  Similarly, coral reef destruction and extreme sea level rises might be avoided if the 1.5C limit is achieved.

“If the world puts all its resources into finding ways to generate power without burning fossil fuels, and if there were international agreements that action must happen instantly, and if carbon emissions were brought down to zero before 2050, then a rise of no more than 1.5C might just be achieved,” said Dr Ben Sanderson of the National Center for Atmospheric Research in Boulder, Colorado.  “That is a tall order, however.”
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Many scientists now believe the most realistic strategy is to overshoot the 1.5C target by as little as possible and then, once carbon emissions have been brought to zero, carbon dioxide could be extracted from the atmosphere to start to cool the planet back down to the 1.5C target.  In other words, humanity will have to move from merely curtailing emissions to actively extracting carbon dioxide from the air, a process known as negative emissions.

Read more at Scientists Warn World Will Miss Key Climate Target

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