16 August 2014

The Failure of the UK Climate Change Act

The Belgian think tank Bruegel points to data showing that the United Kingdom's GDP has returned to pre-economic crisis levels, as shown above. This allows us to do a quick and intuitive examination of how much the UK economy has decarbonized over that time period, and how that rate of decarbonization compares to that implied by the UK Climate Change Act.

As a refresher, decarbonization refers to the rate of decline in carbon dioxide emissions to GDP. In order for the UK to hit the targets prescribed in the UK Climate Change Act for 2022, it will need to achieve consistently an annual rate of decarbonization of  more than 3%, for any GDP growth rate greater than 1% per year. For more detail, and a full exploration of the quantitative implications of the UK Climate Change Act for decarbonization of the British economy, see my 2009 paper in ERL (open access).

With the UK GDP in 2014 at the same level as it was in 2008, it allows us to calculate a simple rate of decarbonization, as it will be exactly equal to the annual rate of emissions decline.

The 12 month (ending 2nd quarter 2008) carbon dioxide emissions for the UK for 2008 was 536.1 million metric tonnes (data here in XLS).  The trailing 12 month (ending first quarter 2014) carbon dioxide emissions for the UK for 2014 was 507.9 million metric tonnes (data here in XLS).

These data imply a rate of decarbonization of -0.9% per year. This is far less than would be needed to hit the targets of the UK Climate Change Act. Last year I calculated an update of the UK decarbonization rate through 2012, which arrived at a similar result. That calculation is shown below.
It is also possible to express the magnitude of the challenge of meeting the targets of the UK Climate Change Act in more intuitive terms. The graph below shows how much carbon-free energy (not electricity) would need to be deployed by 2020 assuming constant demand to 2022.
In my 2009 paper, which was written upon passage of the UK Climate Change Act in 2008, I concluded:
The approach to emissions reduction embodied by the Climate Change Act is exactly backwards. It begins with setting a target and then only later do policy makers ask how that target might be achieved, with no consideration for whether the target implies realistic or feasible rates of decarbonization. The uncomfortable reality is that no one knows how fast a major economy can decarbonize. Both the 2022 interim and 2050 targets require rates of decarbonization far in excess of what has been observed in large economies at anytime in the past. Simply making progress to the targets requires steps of a magnitude that seem practically impossible, e.g., such as the need for the UK to achieve a carbon efficiency of its economy equal to that of France in 2006 in a time period considerably less than a decade.

Further, the focus on emissions rather than on decarbonization means that it would be very easy for policy makers to confuse emissions reductions resulting from an economic downturn with some sort of policy success (cf, McGee 2009). However, as implicit in the Kaya identity, a lower GDP does very little to change the role of energy technology in the economy. So during a downturn emissions may level off or even decrease as policy makers of course seek to preserve (and even accelerate) economic growth. Consequently, a more directly useful metric for policy success for efforts to stabilize carbon dioxide concentrations in the atmosphere is the decarbonization of the economy, represented in terms of carbon dioxide emissions per unit GDP.

A focus on decarbonization as the central goal of carbon policy rather than emissions reductions means that to achieve specific stabilization targets the rate of decarbonization of the UK economy must not only exceed the rate of economic growth, but it must exceed rates of decarbonization observed historically in the UK and in other developed countriesNote5. Because no one knows how fast a large economy can decarbonize, any policy (or policies) focused on decarbonization will have to proceed incrementally, with constant adjustment based on the proven ability to accelerate decarbonization (cf Anderson et al 2008). Setting targets and timetables for emissions reductions absent knowledge of the ability to decarbonize is thus just political fiction. . .

The failure of the UK Climate Change Act is yet to be broadly recognized, but when it is, it will provide an opportunity to recast carbon policies in a more effective manner.
Looking back from 2014, that analysis looks pretty good.


  1. I agree. We need decarbonisation rates of 3-4% per annum from 2015-2050 to meet our UK targets, when our record is showing rates of only 1% per annum. If we can't decarbonise quickly enough, we will have to examine other elements of the Kaya Idendity, namely population and/or economic growth itself.

  2. So the idea of setting targets and allowing the market to generate the required to meet them is unworkable. Is that correct?

    "A focus on decarobonization" would mean a directed research program to generate the required technologies. Is that correct?

    These would seem to mean that governments would create an engineering program to supplement the existing scientific program of the IPCC. the output of the engineering program could be judged by the applicability of its technology to potential carbon reduction.

  3. We already have a lot of the technologies in place for carbon reduction we just need cost reduction of the said technologies party through economies of scale.

    I haven’t combusted any fossil fuels directly since 2011 by swapping the gas boiler for a ground source heat pump and swapping my Audi TT for a 100% electric Nissan Leaf.

    CCS wont scale down to the domestic level and thus we need to electrify domestic heating and transport in conjunction with decarbonising power generation.

    No small task but it can be done we just need the political will by getting the fossil fuel money out of politics.

    1. Are you positively sure that the electricity you use for charging Nissan and running your heat pump is not produced by burning fossil fuels at power plant. Remember that only solar, wind, hydro and nuclear energies are fossil free! :)

    2. No small task but it can be done we just need the political will by getting the fossil fuel money out of politics.

      So, the solution to not facing up to the problem that we cannot decarbonise fast enough is to blame some mythical fossil fuel money in politics!

      My country, New Zealand, would gain tremendously by avoiding importing fuels, because our balance of payment issues are our only long term concern. Any politician that could reduce importations significantly would so radically improve our economy that they would be in power for decades. Yet they steadfastly refuse to do so. No amount of money can buy off a political party from long-term power..

      They don't because, in reality, they can't. The problems lie somewhat deeper than facile assertions of "fossil fuel money".

      The decarbonisation brigade need to sort out their house. Make targets that are achievable without pushing us into poverty as Hikerlondon so delightfully suggests. And without positing imaginary barriers in order to avoid facing real ones, like Mark Tebbutt.

      Going fully nuclear would do it. Not only that, but it most climate sceptics are pro-nuclear, so almost all opposition on climate basis would die. But, we quickly find, decarbonisation is actually not that important after all!

  4. It's amazing how informative a formula that some dead-pan as "GDP = GDP" can be...

  5. Hi Roger,

    I looked at both your XLS links but couldn't work out how you got to the 536.1MtCO2 and 507.9MtCO2 numbers you cite here.

    Data from the UK's own Committee on Climate Change show an average 2.5%/yr decrease during 2008-13, whether looking at CO2 only or the wider basket of GHGs (which is what the UK targets are actually set for). See Figure 1.5 in this report:


    That seems quite different to 0.9%. Thoughts?

  6. Roger, you make an excellent point which emphasizes the hazards of allowing bureaucrats to pass laws that are misguided; also why government needs good and proper science advice. Looking at it a little differently, total carbon emissions are a function of economic activity, efficiency and energy mix (carbon vs. non carbon etc.). Kaya reduces to (CO2/GDP) = (total energy / GDP) x (CO2/total energy). Focusing on carbonization - CO2/GDP confounds and confuses the real policy issues - which are energy efficiency and the carbon content of energy usage. Focusing on carbon also ignores other greenhouse gases, but does include other non combustion things such as deforestation and fugitive emissions. Understanding the math certainly helps.