UN Climate Chief: Even "Successful" Paris Agreement Means 3C Increase

[hatrack]

Global temperatures are likely to shoot past the agreed safety limit of 2 degrees Celsius even if a deal is reached at the upcoming Paris climate summit, UN climate chief Christiana Figueres said in Brussels Tuesday.

The problem is that the pledges made by countries ahead of the COP21 talks on how they would reduce their emissions “do not add up to 2 degrees,” said Figueres, executive secretary of the UN Framework Convention on Climate Change (UNFCCC). Two degrees above pre-industrial temperatures has been agreed by countries as a threshold beyond which climate change risks become unacceptably high.

Instead, the climate promises now on the table mean a temperature increase of about 3 degrees by the end of the century, Figueres warned the European Parliament. But even that scenario is better than what would happen without an agreement in Paris, which would mean a global temperature increase of 4-5 degrees Celsius. “Three degrees is much better than 4 to 5 degrees, but it is still unacceptable,” she said.

That level of potential warming worries scientists. “Three degrees of warming increases the risk of strong sea level rise from, for example Antarctica, or the collapse of marine ecosystems, such as Arctic sea ice or coral reefs,” Anders Levermann of the Potsdam Institute for Climate Change Research, told the Carbon Brief for a paper on the effects of overshooting the 2 degree target. “Beyond two degrees of warming we are leaving the world as we know it.”

EDIT

http://www.politico.eu/article/paris-talks-global-warming-target-un-cop21-figueres/

[Nihil]

1. “Three degrees is much better than 4 to 5 degrees, but it is still unacceptable”

Hah, who says that climate scientists are doomers?!

See that optimism & joy in the first part of her response?

That is the thing that those happy mouth-breathing politicians
will take away: "Three degrees is much better!" says UN Climate
Scientist.

[GliderGuider]

2. This is exactly what I've been expecting since COP15 in Copenhagen

Six years later, NOTHING has changed.

The allure of BAU is so powerful, it's almost like constant growth in energy consumption is programmed into our species DNA by the laws of physics or something...

[GliderGuider]

3. Here's an interesting factoid

While the growth in CO2 emissions from fossil fuels has been decelerating since COP15, the growth in atmospheric concentration has not. I find that disturbing.

[GliderGuider]

4. Is this a sign that the CO2 sinks are saturating? Maybe, maybe not.

The trends over the last five years MAY indicate a saturation of CO2 sinks. However a look at a longer time series shows that the concentration growth rate is quite insensitive to short-term changes in emissions growth. The Earth System is far too complex to draw conclusions from a 5-year time window.

It looks to me as though the only sure way to reduce the growth rate in atmospheric CO2 concentrations is to have outright reductions in global CO2 emissions over a decade or two - during which time the atmospheric concentrations will still be growing.



One other thing to notice is that the concentration growth rate itself is increasing - meaning that the second derivative of the concentration growth is positive. That's very worrisome.