rss feedMethane emissions and the Committee on Climate Change
I admire the Committee on Climate Change (CCC) and welcome their recent report to Parliament. However, I read the report with the knowledge that the CCC is sponsored by the Department of Business, Energy and Industrial Strategy (BEIS). I think that BEIS values business interests over climate climate change. (I have made a submission to the Labour Party Policy Forum, Climate Change and BEIS.)
BEIS also appoint the members of the CCC.
But the CCC does not always follow the BEIS line. For example, in the report to Parliament, the CCC gives space to examine the emissions due to UK consumption. BEIS prefers territorial measures of emissions, which exclude emissions from shipping, aviation and imports. BEIS uses the fall in this measure of emissions to claim the UK is a leader in climate change action. Greta Thunberg has criticised this. As reported by the Guardian she said:
Since 1990 the UK has achieved a 37% reduction of its territorial CO2 emissions, according to the Global Carbon Project. And that does sound very impressive. But these numbers do not include emissions from aviation, shipping and those associated with imports and exports. If these numbers are included the reduction is around 10% since 1990 – or an an average of 0.4% a year, according to Tyndall Manchester.
The CCC must be congratulated in allowing enough explanation of the difference in accounting methods to show the issue – even if there is no direct criticism of BEIS. On consumption emissions the CCC says
despite rising consumption, emissions have also fallen, although more slowly (by 18% from 2008 to 2017, the latest year of available data).
However, in the ten years since the peak in 2007 (at the start of the 2007/8 economic crash) this fall was 23% but in the eight years since 2009, just after the 2007/8 economic crash, emissions fell by 9%. Which is the most significant? The 10 year fall from the peak, the subsequent 8-year fall after the financial crash or the 9-year mid-crash figure?
I suspect the choosing the fall of 18% in 9 years is a political compromise, partly hiding the very slow rate of fall since.
Another topic, to which the CCC has given some attention, is methane emissions. Methane emissions get several mentions in the CCC report, with several recommendations about how to curb them. Phrases in the report concerning methane include:
- leakage of methane from the gas grid
- rising emissions from the oil and gas sector and from ruminant agriculture
- Methane accounted for 56% of emissions from agriculture in 2018
- 70% of emissions from the waste sector in 2018 were methane
- Establish a policy to reduce levels of methane leakage [in industry]
The CCC also say:
Some societal choices that lead to a lower demand for carbon-intensive activities, for example an acceleration in the shift towards healthier diets with reduced consumption of beef, lamb and dairy products, and an increase in journeys being made by walking and cycling.
Pointing out methane-heavy activities is good progress even if it is necessary to mention health. However, if the CCC were not stuck in a political (open) prison, would they go further and advocate policies which would drastically cut methane emissions further? e.g.
- a tax on beef, lamb and dairy products
- creating a task force to cut emissions from industry
- fines on gas suppliers for leaks
- immediately covering landfill sites with 1m of earth
- a public methane awareness programme
One advantage of cutting methane emissions is that it slows climate change quickly. Some have argues that the effect only lasts for a short time so is not yet an important policy. In Cheating with temperature, I argue that this overlooks heating the oceans, melting ice masses and warming the ground in permafrost regions. These cause sea level rise and increase the risk of serious climate feedbacks.
A pause in global warming might also help buy time while other methods of combating climate change were found. So those of us that think the climate change has reached a dangerous state, would welcome even stronger measures on cutting methane emissions.
The note below is an attempt to raise the importance of methane mitigation with the CCC – by continuing a correspondence I started in 2008.
Comments are welcome, particularly of my simple version of the physics of Short Lived Climate Forcing.
A note on Short Lived Climate Forcing for the Committee on Climate Change
Geoff Beacon, June 2020
Dear Committee Member,
At the end of the All Party Parliamentary Climate Change Group meeting on 2nd July 2008, Lord Adair Turner, then Chair of the Committee on Climate Change, agreed to answer questions by email. I sent several questions. One of them was:
8.1 Can the CCC answer questions such as: If one gigatonne of CO2 is released into the atmosphere this year, how much must be removed in twenty years time to bring the climate back to the state it would been in had the release never happened. To what extent do positive climate feedbacks affect this question?
After some prompting, I received answers in October 2009. They included:
Q8.1: There is recent research (two papers on this subject are here
http://www.cccma.ec.gc.ca/papers/ngillett/PDFS/nature08047.pdf
and here
http://www.iac.ethz.ch/people/knuttir/papers/allen09nat.pdf)
suggesting that the specific timing of CO2 emissions is less important than the overall total amount of CO2 that is emitted over time. Including the effect of carbon cycle feedbacks in the climate system, these studies imply that a gigatonne of CO2 emitted in 20 years’ time would have the same result (in terms of temperature increase) as a gigatonne emitted now.
I draw your attention to “would have the same result (in terms of temperature increase)”. There are two scenarios:
- S1: One Gt CO2 released this year
- S2: One Gt CO2 released after 20 years
When considering the difference in emission scenarios, a simple view of the physics is this:
In the case of S1, the extra CO2 in the atmosphere heats the Earth for 20 years, raising the surface temperature of the Earth. During and after the twenty years, the elevated temperature causes the loss of heat to space.
At the end of twenty years, the effect of the 20 years of extra heating on the Earth’s surface temperature diminishes quite rapidly so that the difference between S1 & S2 vanishes.
This means, broadly speaking, that after a short period of adjustment S1 & S2 have more-or-less the same effect on the surface temperature of the Earth as they will have similar concentrations of CO2 in the atmosphere.
However, the extra heating caused by 20 years of elevated CO2 in scenario S1, will have had other effects, which do not diminish so rapidly. For example, some of the extra heat will have warmed the oceans and some will have melted land grounded ice mass, both of which contribute to sea level rise.
Another example of the effects of S1 is the warming of permafrost in Arctic regions, where surface heating can penetrate the ground over long time scales. In addition there is the release of greenhouse gases from permafrost regions from surface melting.
In short, temporary warming in S1 may cause a short-lived rise in Earth’s surface temperature, which is limited. However, there are other effects, not directly driven by current surface temperature, which have greater consequences.
While it would be important to know to what extent CO2 emitted now is worse than an equal amount emitted in 20 years time, there is a significant related issue. For example, there are emissions of Short Lived Climate Forcing (SLCF) agents, which can be reduced by policy driven actions.
Methane is the main example of a Short Lived Climate Forcing agent. The CCC will be aware that some scientists advocate cutting methane emissions quickly to help the task of combating climate change. Others, who may see the surface temperature of the Earth as the only really important effect, seem to believe that this is a much less important issue, at least until the Earth’s temperature nears a peak.
Can CCC give a fuller reply to my Question 8.1 and address aspects of short-lived excess warming other than its effect on the surface temperature of the Earth?
If short-lived warming is important, so are policies for reducing them, such as deprecating the consumption of meat from ruminants. Does the CCC have a view on this?
Sincerely,
Geoff Beacon
