It seems unlikely that an agreement to cut the world’s CO2 emissions from its coal, gas and oil consumption will be reached in the foreseeable future. It is far more likely that these emissions will fall rapidly as a result of supply difficulties caused by the progressive depletion of their sources. The group’s efforts to promote Cap and Share might therefore be better-directed as a way of sharing out the scarcity rent that would otherwise accrue to the fossil energy producers rather than as a proposal to limit global fossil fuel use since that is happening anyway.
In any case, fossil-fuel CO2 is estimated i to have contributed only 32% of the warming that occurred in the 1990s while, according to the IPCC’s Fourth Assessment Report, CO2 from other sources such as deforestation and the ploughing of grasslands added a further 10% to CO2′s total impact. Even this 42% may be an over-estimate as it ignores the effects that the increase in the amount of water vapour, itself a greenhouse gas, may have had. If allowance is made for this, CO2′s total contribution to warming may have ranged between 9 and 26% ii and, consequently, the fossil component may lie in the range between 7% and 20%.
These figures indicate that the UNFCCC’s single-minded concentation on reducing fossil fuel CO2 emissions has been a mistake and that, while it should continue to regard fossil CO2 as extremely important, it should devote much more attention than it is currently giving to devising policies to reduce the other emissions that are causing warming. At the group’s recent Climate Weekend in Cloughjordan, it was agreed that the Feasta climate group should begin to work along these lines too.
The major emissions for which the group and the UNFCCC should be trying to develop policies are, in order of their current warming effect, methane (23.8% of the current warming effect if water vapur is ignored), black carbon, (15%), halocarbons, (10.3%), nitrous oxide (4.7%) and low-level (tropospheric) ozone (4.2%). As chart 1 shows, their warming effects are currently partially offset by sulphur dioxide and other aerosols from the burning of coal and other sulphur-containing substances (37% offset), organic carbon from the incomplete burning of organic compounds (13%) and changes in land-use because land cleared of forests or scrub normally reflects more light. (4.7%)
Adding the offset percentages together, it will be seen that they counter just over half of the warming effect produced by CO2 and the other gases. It will be also be seen that all the offsets are the accidental side effects of the warming emissions themselves. Burn less coal and the cooling effect of the sulphur dioxide will be reduced. The protection provided by organic carbon is the other side of the black carbon coin and the increase in the amount of heat relected into space is about the only good thing to emerge from forest clearance.
Just as different policies are needed to deal with CO2 from fossil fuel use and from deforestation, different policies will be needed to deal with the various sources of the other gases. For example, methane from cattle or from rice paddies needs to be treated differently to methane from, say, oil and gas exploration or from the melting of the permafrost since the cattle and rice emissions are just elaborations of the natural carbon cycle whereas the oil and permafrost emissions add carbon to that cycle.
In addition, it would be a mistake to prioritise action on each of the warming gases according to either its current contribution to total warming or each molecule’s warming effect in relation to a molecule of CO2. Other factors need to be considered such as the length of time each molecule is likely to stay in the atmosphere and whether or not it interferes with the breakdown of other ghgs. For example, nitrous oxide is particularly damaging. It is responsible for destroying twice as much ozone as the next worst ozone depleting anthropogenic substance, CFC-11, a refrigerant. This is serious for two reasons.
One is that ozone filters out ultra-violet radiation coming from the sun, leading to an increase in skin cancers and cataract-induced blindness. Plant cells are also damaged, slowing growth. The other reason is that ozone destroys atmospheric methane. Consequently, an increased nitrous oxide concentration is likely to lead to an increased methane concentration and thus a greater total warming effect than from the nitrous oxide alone.
Another factor to be taken into consideration in determining priorities is the amount of time an action will buy to allow other changes to be implemented. “Cutting halocarbons, black carbon, tropospheric ozone and methane can buy us about 40 years before we approach the dangerous threshold of 2°C warming,” Veerabhadran Ramanathan, a distinguished professor of climate and atmospheric sciences at the Scripps Institution of Oceanography, San Diego, said in October 2009 at the launch of a paper iii he co-wrote with Nobel Laureate Mario Molina and others. “If we reduce black carbon emissions worldwide by 50 percent by fully deploying all available emissions-control technologies, we could delay the warming effects of CO2 by one to two decades and at the same time greatly improve the health of those living in heavily-polluted regions,” he added.
The paper identifies four “fast-action regulatory strategies” which the authors think could take effect “within 2–3 years and be substantially implemented within 5–10 years, with the goal of producing desired climate response within decades.” Besides reducing black carbon, they propose running down the production of hydrofluorocarbons with a high global warming potential, accelerating the phase-out of hydrochlorofluorocarbons and recovering and destroying stratospheric ozone-depleting substances from scrapped products such as refrigerators.
Their third proposal is to reduce emissions of pollutants such as carbon monoxide, the nitrogen oxides, methane and volatile organic compounds. These undergo complex photochemical reactions and form ozone in the troposphere which extends up to 15 km above the ground. The paper says that this tropospheric ozone has increased by 30% since pre-industrial times and its contribution to global warming is as much as 20% of that due to CO2. In addition, it damages human health and, as a 2008 Royal Society report iv showed, could have caused $26 billion worth of damage to crops in 2000. Reducing this form of ozone by half could delay rising temperatures by another decade, Professor Ramanathan says.
The paper’s fourth proposal is to increase the sequestration of CO2 already in the air through improved forest protection and biochar production. Biochar is charcoal produced from biomass which is ploughed into the soil to retain nutrients, cut the release of methane and nitrous oxide and increase fertility. Moreover, by encouraging the development of fungi and micro-organisms, it increases the soil’s carbon content by much more than its own weight. It is estimated that the worlds’ soils contain 2,500 billion tonnes of carbon and the plants lock up a further 500 billion tonnes. The atmosphere contains some 600 billion tonnes.
Thus, getting the amount of carbon in the atmosphere down by 25% involves just a 5% increase in the tonnage held in plants and soils. This would seem quite do-able. The Molina/Ramanathan paper cites a study by Lenton and Vaughan v which suggests that, under highly optimistic scenarios, the capture of atmospheric CO2 by plants grown to provide bio-energy followed by capturing and storing the carbon they release when burned combined with afforestation and biochar production may have the potential to remove 100 ppm of CO2 from the atmosphere. This, alone, would return the atmospheric concentration of CO2 to near preindustrial levels and reduce radiative forcing by 1.3 watts per square metre. “However,” the paper says in major understatement, “this may conflict with food production and ecosystem protection”. A proper assessment of the pros and cons of the possibilities raised by Lenton and Vaughan is required, particularly as proposals on similar lines have been attacked by the Biofuelwatch group in papers such as “Biochar: A critical review of science and policy” which can be downloaded from www.biofuelwatch.org.uk/biocharsciencereport.php
Feasta is, of course, already working through its Carbon Cycles and Sinks project on the potential for getting the world’s soils to remove more carbon from the atmosphere. Currently, plants and soils take up about 10.6 billion tonnes of CO2 a year plus or minus 4 billion tonnes. This compares with 8.1 billion tonnes plus or minus 2.9 billion tonnes released by deforestation and ploughing grassland. Both these pairs of figures come from the Woods Hole Research Center which evidently thinks that the level of uncertainty about the net amount of CO2 being taken up by plants and soils is very high. However, plants and soils are clearly a net sink as the rate at which CO2 is increasing in the air than is less than is being released by land use change and fossil fuels combined and the Woods Hole estimates show that it is most unlikely that all the difference can be accounted for by the amount taken up by the sea. Moreover, it is reasonably certain that if all deforestation and land use change ceased, roughly half of current fossil CO2 emissions would be taken up by soils and plants.
The Feasta climate group will have to change radically if it is to begin to develop a full set of policies for developing sinks and for reducing emissions of the most important ghgs. One way of doing this would be to set up a series of sub-groups to keep up with the research and the thinking in the areas we decide to try to cover. Such sub-groups would allow for an interchange of ideas and information between members which would be far better than researching a topic on one’s own. However, in ideal circumstances, no-one would belong to just one sub-group but would be active in at least another as well. For example, a member of the methane sub-group could also be a member of the nitrous oxide sub-group or the soil amendment (biochar) sub-group, so that information could move from one sub-group to another.
The list of topics at the end doubles as a preliminary list of the subgroups the group might want to form. Members may be able to think of better ways of dividing up the ground to be covered. A look through Topic 1 indicates the cross-over memberships that the CO2 subgroup would require. For example, someone looking at the potential of bogs as sinks would be needed to contribute ideas on eliminating bogs as a source, while members of the methane sub-group, the forestry sub-group and the grassland and arable soils sub-group would also be needed. A very large increase in the number of people active in the climate group as a whole would be needed to enable the work to be done.
A good way to get the additional members and to get the sub-groups going might be to call a two- or three-day conference in spring next year at which papers would be given on the fourteen or so subject-areas identified in the topics list. The papers could then be published as a book, exactly as was done after Feasta’s New Emergency conference in 1999, from which the book Fleeing Vesuvius emerged.
The book, though worthwhile in itself, might only be a starting point. Those attending the conference are likely to wish to follow up on some of the questions raised and form the sub-groups to do so and papers produced by the groups could be published either as standalone documents or brought together in a report which would present a reasonably detailed picture of what might be achieved by a programme that targetted all emissions sources and promoted the development of sinks in an integrated way. The report could set out to the answer the question “Do we still have the ability to avert a climate catastrophe and, if so, what do we need to do?”
It should be possible to find funding for a conference and the publication of a book if this is what the group would like to do. However, if 14 or so sub-groups were set up as a result of the conference, a lot of co-ordination and administration would be required and, although the work within the subgroups would be unpaid, some full- or part-time paid workers would be needed, especially in the months leading up to the publication of the report. Significant funding would be needed for that stage but the publication of the book might make that easier to obtain.
We would therefore be grateful if you would let us know if you would support the conference project by trying to attend yourself and urging others to come. Please let us know too if you would like to give a paper or suggest the names of people we might approach to do so.
David Healy Brian Davey Richard Douthwaite: 16th June 2011
i – Woods Hole Research Center, http://www.whrc.org/carbon/index.htm
ii – Earth’s Annual Global Mean Energy Budget, J. T. Kiehl and Kevin E. Trenberth, National Center for Atmospheric Research, Boulder, Colorado http://journals.ametsoc.org/doi/pdf/10.1175/1520-0477%281997%29078%3C0197%3AEAGMEB%3E2.0.CO%3B2
iii – “Reducing abrupt climate change risk using the Montreal Protocol and other regulatory actions to complement cuts in CO2 emissions” by Mario Molina, Durwood Zaelkeb,1, K. Madhava Sarmac, Stephen O. Andersend, Veerabhadran Ramanathan,and Donald Kaniaruf, http://www.pnas.org/content/early/2009/10/09/0902568106.full.pdf+html
iv Royal Society (2008) “Ground-level ozone in the 21st century: Future trends, impacts and policy implications”. Available at http://royalsociety.org/displaypagedoc.asp?id31506
v – Lenton TM, Vaughan NE (2009) “The radiative forcing potential of different climate geoengineering options£.Atmos Chem Phys Disc 9:2559–2608
