The Paris climate talks concluded Friday with an agreement, and the basic tenets of the deal have trickled out over the week-end. The goal is to hold the increase in global temperature to two degrees Celsius. A more ambitious 1.5 degree ceiling is something to which nations may aspire. If nothing at all is done, an increase of 3.7 degrees by the end of the century is a done deal. With all of that in mind, the deal is better than nothing, but its excessive reliance on volunteerism guarantees that it will not be the final word if the planet isn’t to over-shoot the two-degree target.
The first thing to consider is the general arbitrariness of the proposed two-degree cap relative to pre-industrial levels. This figure was largely pulled from thin air in Europe back in the 1990s. The planet has already undergone a one-degree increase, and the consensus is that 1.5 degrees is probably not possible without draconian changes. So, the two-degree increase is a handy level to use because it remains possible.
The mechanism by which the diplomats achieved agreement among almost 200 nations is one that relies more on shame and social pressure rather than legal force. Each nation will set its own targets for carbon emissions, and it will then tell the world what it is going to do. Five years on, the next set of actions to achieve the next target is set. The first stocktaking will be in 2018, and the next round of proposals and targets is set for 2023.
What is legally binding in the agreement is the setting of targets and the transparency needed for the name and shame approach to ratchet things up. What each country does is a matter for it to decide on its own. Each country will establish a “nationally determined contribution” and explain publicly how it will achieve it. There is absolutely nothing preventing a nation from setting a NDC of nothing at all and stating that it will do nothing to achieve that. Moral pressure alone will make a country set an NDC and create a plausible plan to achieve it.
While getting all the countries involved to agree to anything is difficult, it might have been better to offer a cap of 2.5 degrees but then establish a mechanism for meeting that much more lenient cap that has some real teeth. The risk. as it stands. is that the voluntary moves might create a situation where a 2.7 or 2.8 degree increase occurs, at best. It is conceivable that three degrees could not form the upper limit if one relies on volunteerism.
More over, a great deal of the future strategy hinges on negative emissions. That is, the planet is going to need to rely more and more on processes that remove carbon from the atmosphere. So long as fossil fuels form the basis of the global economy, negative emissions remains a desperation move. This can be anything from planting trees to high-tech methods of carbon sequestration. However, positive emissions from developing countries will continue to increase, although perhaps at a slower rate than without the deal.
Another matter that the agreement doesn’t address is the thawing of the permafrost. Gigatons of carbon are locked up in the permafrost of the Arctic and sub-Arctic (and in certain Antarctic and Alpine areas), and the increase in the global temperature will cause that to thaw and unlock the carbon (mainly as methane) it holds. Most of this sits in Russia and Canada, but it is unlikely that their overall carbon emissions under their NDCs will include this.
The Paris agreement is the best currently available, and it is a start. However, the increase in global temperature will continue, and further actions will be needed.