It might have gone largely unreported on this side of the Channel, but over in France a battle is raging that could eventually determine the pace and manner at which not only the French economy, but the entire global economic system, transitions towards a low carbon future.
In a surprise move the French Constitutional Council last week ruled that a carbon tax that was due to come into effect on January 1st was unconstitutional on the grounds that the large number of loopholes offered to businesses meant that the tax "violates the equality enjoyed by all in terms of public charges".
The decision represents a major blow to the political authority to President Nicolas Sarkozy, who had faced down huge public and political opposition to impose a carbon tax of €17 a tonne on oil, gas and coal that he argued was essential to the country's efforts to curb emissions, and has prompted a rapid response from the government which has vowed to have a reformed version of the legislation in place by April.
As a result, a debate is now raging within government as to how to impose the new tax equitably while still protecting those industries that would see their international competitiveness irretrievably damaged and avoiding a bout of the French national pastime of oil drum-burning, pitchfork-waving public protest.
A number of proposals are now being debated, including removing some of the exemptions, removing all the exemptions but imposing a lower carbon tax on those sectors such as farming and haulage that would be worst affected, and removing the exemptions for industrial emitters and carbon intensive firms but then allowing them to buy the emission allowances they have to purchase under the European emissions trading scheme at a reduced price.
Policy makers the world over will now be watching closely to see which approach the French opt for and how effective it proves.
Their interest is driven the two crucial issues which the French are wrestling with and which all governments will have to address if they are to adequately accelerate the transition to low carbon energy sources.
The first problem is how to impose an effective price on carbon without simply incentivising energy intensive industries to up sticks and move to territories where there are no such charges.
To date the European emissions trading scheme, the French government and others have opted for the exemption model - effectively offering a free ride to those industries most likely to leave. So far this approach has sort of worked and there have been no reports of firms exiting the EU because of the ETS. But as the French Constitutional Council pointed out there is an inherent problem in this approach which means that a larger chunk of the financial burden associated with carbon pricing mechanisms falls on those sectors of the economy that are least able to pack up and leave.
This is doubly problematic as those sectors that can't easily move elsewhere - energy generation, food production, retail, and on a human level the poorer sections of society - could do with the money they are shelling out on carbon taxes or emissions allowances to spend on the technologies they need to cut their emissions. Carbon pricing may mean they have an increased incentive to cut their emissions, but they are effectively subsidising businesses which due to the exemptions they are granted have more money in their back pocket but less of an incentive to cut emissions.
National policy makers have long been desperate to work out a solution to this conundrum, and will have become even more desperate after the fudged outcome from the Copenhagen Summit made the chances of a genuine solution in the form of global carbon pricing mechanism even less likely.
It will be intriguing to see how the French go about tackling the problem. Will Sarkozy simply seek to strike a slightly different balance that still protects those industries that argue they represent a special case, or will he take on board the central concern of the Constitutional Council and simply impose the tax across the board? If he goes with the latter option, it will be interesting to see if, as they have claimed, a relatively modest carbon tax really will bring French industries to their knees. Will companies really up sticks in large numbers and leave for China and India as a result of €17 a tonne charge on carbon? Personally, I'm guessing not.
Which leads nicely to the second reason, all eyes should be on France over the next few months. Namely, will a national carbon tax in a large industrialised economy work? Will it cut emissions and accelerate the development of a highly competitive and prosperous low carbon economy?
There is a growing school of thought - including amongst some of the energy firms and other carbon intensive businesses that will directly impacts - that a carbon tax would prove more effective at providing the certainty firms need to justify long term investments in low carbon infrastructure.
A cap-and-trade scheme may prove more sophisticated and is in theory a more cost effective means of cutting emissions, but as the EU emissions trading scheme has proven time and time again it also introduces a volatility to carbon pricing that makes it very difficult for businesses to judge their low carbon investment plans.
With the UK preparing to launch a national cap-and-trade scheme in the form of its Carbon Reduction Commitment, the French carbon tax raises the prospect of two test cases on either side of the Channel which will provide the perfect opportunity to compare the different models' effectiveness.
I may be a self-admitted Francophile, but personally my prediction would be that while a carbon tax will prove less popular and more challenging for many carbon intensive firms, it will also deliver deeper and faster cuts in emissions while providing a greater competitive advantage to emerging low carbon businesses.
In the meantime, let's hope that Sarkozy gets his way and manages to get a carbon tax in place, otherwise we'll never know.
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