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Temperature Target May Doom Climate Talks, Study Says

At the much-heralded climate summit in Copenhagen in 2009, world leaders agreed to limit manmade global warming to less than 2°C (3.6°F) above preindustrial levels. The agreement at Copenhagen, however, and in multiple rounds of subsequent negotiations, hasn’t led countries to make actual commitments to the kind of emissions reductions that would put the world on a path to meeting that 2°C target.

According to a new study published in Proceedings of the National Academy of Sciences, however, this seeming inconsistency is not just unsurprising: it was inevitable. By focusing on the 2°C goal, negotiators inadvertently guaranteed that their efforts would fail, because there’s no hard evidence that any specific temperature target marks a dangerous threshold, with clear consequences for crossing it (instead, there is plenty of evidence that more and faster warming entails greater risks of major consequences, such as the collapse of the polar ice sheets). This uncertainty, the study argues, provides an incentive for countries to be free-loaders, jumping on board with the agreement without making potentially costly emissions reductions.

The U.N. Climate talks in Copenhagen.
Credit: Flickr/UNClimatetalks

The main message, therefore, is that countries should not rely so much on the notion of a climate change “red line,” beyond which catastrophe could occur, as the basis for making emissions reduction commitments.

This might come as a surprise to political leaders, who for more than two decades have struggled to reach agreement on what level of temperature change, or what atmospheric concentration of planet warming greenhouse gases, would constitute “dangerous human interference” with the climate. For them, just agreeing to the two-degree target was viewed as an accomplishment in Copenhagen.

The study is based on results from a simulation game played by 400 students, who played the game for real money. The students can be thought of as climate negotiators. Scott Barrett, a professor at Columbia University’s Earth Institute and a coauthor of the study, said that in practically every simulation, despite having the equivalent of a temperature target to shoot for, the players in the game committed to emissions limits that allowed the amount of planet warming greenhouse gases in the atmosphere to soar to what would almost certainly be “catastrophic” levels.

The problem, Barrett said, is that unless uncertainty about the threshold can be reduced to near-zero, individual countries have an incentive to do less than what would be required to avoid exceeding the threshold. In reality, this uncertainty can never be reduced to near-zero, Barrett said, because of the inherent scientific unknowns about what causes abrupt and catastrophic climate change.

If uncertainty could be reduced to near-zero, though, climate negotiations would be transformed from a classic “prisoner’s dilemma,” in which countries have a perverse incentive to do less than what is required in order to solve a shared problem, and into a coordination game, in which countries would work with one another to ensure they are making sufficient commitments to meet a collective goal.

“The long history of climate talks and climate behavior is pretty clear, countries say one thing and do another,” Barrett said. He said this study, which shows that identifying a “red line” may actually hinder policy action, provides new insight into the failure of international climate talks.

“The purpose of all this research is to understand first of all why things have gone wrong,” he said. “You need a proper diagnosis of the illness before you order treatment.”

Barrett said negotiators should seek ways around the “prisoner’s dilemma,”  perhaps by designing a series of smaller agreements that target individual greenhouse gases, rather than trying to craft an all-encompassing treaty that sets emissions reduction goals for entire economies.

The next round of U.N. climate talks kick off on November 26 in Doha, Qatar. 


By Charles Winter (Washington, DC 20008)
on October 8th, 2012

“Everything has changed, except our way of thinking. And so, we drift toward unparalleled catastrophe.”—Einstein

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By Gail Zawacki (Oldwick, NJ 08858)
on October 9th, 2012

This is another indication - as if any were needed - that an emphasis on climate change from CO2 emissions is a failed strategy.

It might be far more effective if scientists and activists would stop obsessing over CO2 and instead, research and inform the public about the emissions intrinsic to industrial processes that are directly affecting humans everywhere, NOW.

In a nutshell, that would be the production of reactive nitrogen from fuel and agriculture, which is causing eutrophication of water and producing tropospheric ozone.

The ecosystem is collapsing before our very eyes and yet even scientists who study the impact of ozone on vegetation refuse to alert policy makers to this existential threat to our food supply.  All you have to do is look around to see that trees are dying - photos here:

It’s unfortunate because if people understood the very clear choice we have between food and unsustainable growth based on high energy consumption, I tend to think most would choose food.

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By Jeff
on October 9th, 2012

The UN COP process, the US Congres, RIO +20, and any other process aimed at addressing climate change that involves politicians are all equally impotent for the same reason. They are all wholly owned subsidiaries of the 1%.

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By Dave (Basking Ridge, NJ 07920)
on October 9th, 2012

Gail, I like your blog. Thanks.

In the context of your comment, and as you probably know, tropospheric ozone and nitrous oxide are indeed two of the anthropogenic greenhouse gases, along with carbon dioxide (CO2), methane and certain halocarbons.  However anthropogenic CO2 has the biggest impact on global warming. So to your point that “It might be far more effective if scientists and activists would stop obsessing over CO2 and instead, research and inform the public about the emissions intrinsic to industrial processes that are directly affecting humans everywhere, NOW.” Clearly, as you point out, tropospheric ozone is a pollutant as is nitrous oxide gas and nitrogen compound runoff from agriculture into river water and then into the oceans also poses a known and major danger to the rivers and oceans and the life they support. However, global warming is a central concern that is indeed also directly affecting humans everywhere NOW. Just check out the growing issues of extreme weather, droughts, wildfires, floods and rising sea level.

Trying to rein in CO2 emissions is not a failed strategy. The EU overall is doing much better than most in that respect. The failure is in the stupidity and corruption of governments like the one here in ignoring this major issue.  It is not even on the current campaign agenda and the US is still in the midst of the worst drought since the 1930’s and this year is shaping up to be the warmest on record.  This may not affect us so much in NJ but it sure as hell is devastating to a lot of people in other parts of the country and it has also substantially impacted food supply this year. Few climatologists will tell you that global warming is not a factor in this.

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By Milton Lachman (Indianapolis, IN 46220)
on October 10th, 2012

No climatologists are physical chemists, which duly explains
why none of them know that no linear, symmetric molecule can
be a greenhouse gas, without most, if not all, being such.
Thus, if CO2 is one, then so is O2, especially given the fact
that there is vastly more O2 in the atmosphere. The original
author is thereby justfied in advocating that the focus be
shifted to other emissions: for every CO2 molecule emitted
from the burning of hydrocarbons, an O2 molecule must be
removed, which is an inconvenient truth that none of those
who stand to profit from trading carbon credits will ever

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By Dave (Basking Ridge, NJ 07920)
on October 10th, 2012

Oh really Milton…  “if CO2 is one then so is O2” is simply just not true.  I am quite familiar with gaseous IR spectroscopy and I can tell you that your statement displays no understanding of IR activity in gases whatsoever, which is what the atmospheric greenhouse effect is about. 

Try this University of Alberta site: King’s Centre for Visualization in Science.
Click on the run applet entitled “Collisional heating in the atmosphere”. It is lower down on the page so just page down to find it.  The applet explains IR absorption in the atmosphere by GHG’s, otherwise know as infrared (IR) active gases, such as CO2 versus non IR active gases such as O2 and N2.

To your confused statement about symmetry…  All GHG’s, like CO2 (vibrational and bending) or H2O (rotational bands) have an electric dipole moment, which an IR photon can use to exchange energy.  N2 and O2 are symmetric molecules and also made up of the same atom and instead do not have an electric dipole moment and so they cannot be heated in the same way.  Argon is an atomic gas (about 1% of the atmosphere) and is hence also IR transparent. Hence the GHG components responsible for the atmospheric greenhouse effect are minor (water vapour) and trace constituents including CO2, CH4, N2O, CFC’s and O3.

I hope this helps you.

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