The 2008 Climate Change Act requires by 2050 that we have reduced greenhouse gas (GHG) emissions by at least 80% from their 1990 levels.

The path to that reduction is set out in a series of Five Year Carbon Budgets.

DECC’s Final UK Emissions Estimates 1990-2013 has a table showing emissions since 1990 which I have turned into a chart and added the budgets.

Lastly, I have added, DECC projections out to 2035 from DECC Updated Energy and Emissions projections 2014.

The first lesson of this chart is since 1990 emissions have fallen a lot: from 809 MtCO2e (1990) to 568 MtCO2e (2013).1 That’s 30%.

The zig-zag of emissions over the 2008-12 budget conceals the fact that the budget for that period was met though only just. Emissions of all GHG from 2008-12 were 3017.5 MtCO2e a whisker short of the 3018 MtCO2e budget. Well that was close - or maybe not. There are other series of CO2 emissions, for instance BP Statistical Review of World Energy 2015, the Netherlands/EU produced Trends in Global CO2 Emissions(EDGAR) and the US Energy Information Authority according to these we missed the target (see the inset chart). Did DECC massage the data to get under the target? Who knows - but the important thing is the big drop since 1990.

DECC’s future projections are shown in grey. You can see that present policies are projected to become steadily less effective until after the 2023-27 (50%) budget they more or less stop generating any further reductions. So the second lesson of this chart is that UK climate policy is radically incomplete. This is because it is focused almost exclusively on reducing emissions from electricity generation. Wind onshore, wind offshore, tidal, new nuclear, biomass burning, wave technology, carbon capture and storage - all the memes floating around the public space are to do with electricity generation. Once that is complete (and the new runway at Heathrow is operational) new policies would be required.

The lesson of this second chart is the decline in emissions was the result of the substitution of gas for coal and oil in electricity generation, and especially the replacement of coal (gas produces about 1/2 as much CO2 as coal). But, since about 2000 the decline in coal use has stopped. Further, after about 2008 one starts to see a decline in the use of gas. Partly this is due to a decline in demand, partly due to increased use of renewables.2

The first lesson of the third chart is that renewables are now a significant contributor - in 2013 they generated 15% of electricity which was a record. The seond lesson is that renewables are displacing gas, not coal.

I have divided renwables into three groups: wind (on and off shore), solar, and all the rest. The last category includes (in order of contribution), plant biomass, landfill gas, and hydro. Other components that contribute less than 5% to the renewable total are ignored except little solar because Amber Rudd (the new Energy Secretary) made some noises just after the election about a massive increase in solar.

Plant biomass doubled from 2011 to 2012 and doubled again to 2013. This is mostly because mighty Drax has started to fire some of its boilers with wood pellets from the USA instead of coal (for which it receives a hefty annual subsidy). The result is that biomass burning competes with wind as the main renewable fuel.

My final chart, which I think is very striking, I have reconstructed from DECC Updated Energy and Emissions Projections 2014 (figure 5.2). The only difference between my chart and DECC’s is that I have started the series at 2000 (where the data starts) rather than 2008. The chart shows the intended energy trajectory of the British government right out to 2035. It encapsulates present policy in “tackling” climate change (and keeping the lights on).

The chart is indexed to 2013, and it is for all energy use, not just electricity generation, though obviously generation is a big component. We see the elimination of coal, renewables increasing steeply to about 2024 and then levelling off at approximately twice present capacity (that would be 30% of generation) as new nuclear starts to appear.3

Gas and oil continue to be used almost unchanged, while nuclear increases steeply after 2020 to about 2.5 times it present capacity. We use gas in domestic boilers as well as CCGT power stations, and petrol/diesle in cars and trucks and neither of those is going to change by 2035.

The numbers at the right of the chart are the projected absolute use of each fuel in Mtoe.4 For electricity the policy is simple: kill coal, build nuclear and renewables.

So, in summary:

Whether it will be done is at present moot. Reading stuff for this piece I was struck at the huge cost of it all. The developing world cannot afford to “tackle” climate change, and I am not sure that this bit of the developed world can either.

So let us finish with a prayer from Prince Charles:

Prince Charles has called for “profound changes” to the world’s financial systems, warning the business-as-usual approach is failing to step up to the challenge of tackling climate change …The prince also reiterated his call for a shift towards a more resource efficient circular economy. “The challenge now is to go much further and much faster, progressively eliminating waste by developing a circular economy that mimics nature’s loops and cycles, rather than perpetuating our largely unsustainable and linear way of doing things,” he said.
Business Green



1. Targets refer to the total of all greenhouse gases not just CO2, accumulated over a five year period, though CO2 is by far the dominant one. The unit is MtCO2e (“million tons of CO2 equivalent”) rather than just CO2. Emissions of GHG’s other than CO2 are converted to CO2 equivalent by reference to their “global warming potential” of the gas. For instance the global warming potential of 1 tonne of methane emitted is equivalent to 25 tonnes of CO2. See for more details.

2. In chart 2 the “other” category is a hotch-potch including nuclear, wind, other-renewables (eg biomass buring, landfill gas), and odd bits of generation (eg “coke-oven gas”). The unit Mtoe (“Million tonnes of oil equivalent”) is a unit of energy - the energy produced by burning a tonne of oil. The fuel used by a nuclear power station is deemed to be the electricity it produced divided by it’s thermal efficiency (typically about 30%). It’s a civil servant’s measure.

3. I have used the low fossil fuel price scenario which assumes a 2015 price of £89 per barrel for Brent crude - the current price is about £60. The “reference” (£96) and “high” (£136) price scenarios are too high. Using the high fossil fuel price renewables are projected to expand to 23 Mtoe instead of 21 Mtoe so it doesn’t make much difference.

4. Mtoe = 1 million toe. The toe (tonne of oil equivalent) is a unit of energy, notionally the energy released in burnig 1 ton of oil. 1 toe = 11,630 kWh = 1661 of Elon Musk’s 7kWh Powerwall batteries.