Monday, November 30, 2015

Planet’s Future Hangs on Paris Legacy

The place de la Republique is covered with shoes as part of symbolic rally organized by the NGO Avaaz during the forbidden COP21 demonstration on November 29, 2015 in Paris, France. The demonstration was banned after the Paris terror attacks on Friday, November 13th. Nevertheless, thousands of people gathered to protest against global warming ahead of COP21conference and an estimated 200 people were arrested after fighting with police. November 29, 2015 (Credit: Patrick Aventurier) Click to Enlarge.
The gathering of 190 nations in Paris for the UN climate change summit – widely known as COP21 – may already have averted the most catastrophic predictions of climate change, but only if those nations that have pledged to reduce carbon emissions keep their pledges.

And a new study warns that containing global warming to within a worldwide average of 2°C above the pre-industrial level is possible only if nations go beyond their promises and step up the momentum for change.

The calculations that confront the assembly of nations in Paris for the next two weeks are simple enough:  if global economies exploit fossil fuels under a “business as usual” scenario and dump ever greater quantities of carbon dioxide in the atmosphere, then by 2100 global average temperatures will have risen by 4°C or more, and sea levels by a meter − with unimaginable consequences for the world’s poorest people.

Dangerously high
That already seems unlikely.  European Union research shows that the targets set so far by the 155 nations that account for 90% of greenhouse gas emissions would restrict global warming to about 3°C above the average for most of human history.

But this is still considered dangerously high.  In the last century, average global temperatures have risen, along with carbon dioxide levels, by 1°C already.  And even 2°C is not considered a “safe” limit.

Researchers from the US and Austria report in Science journal that they looked at the Intended Nationally Determined Contributions (INDCs) announced so far – which extend only as far as 2025 or 2030 – to see what these would achieve.

The news is encouraging:  the INDCs and any future abatement do introduce a chance of meeting the 2°C target, and greatly reduce the risk of a warming that exceeds 4°C.  But everything depends on what happens after 2030.  So the Paris meeting still has a lot to achieve.

Read more at Planet’s Future Hangs on Paris Legacy

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