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THE ARGUMENT FOR 90% CUTS

George Marshall, 20th December, 2001


NOTE- this is a discussion paper based on simple arguments and using very rough data. There are many variables and uncertainties in all the figures quoted, which have been left unstated for ease of readibility. These variables do not significantly weaken the final conclusions.


Central to any discussion about emission cuts is the notion that there is a level of emissions that can be absorbed by natural mechanisms. On 1990 data the IPCC scientists estimated that the planet could absorb approximately 4 gigatonnes of carbon each year. The mechanisms are not well understood, but known to be mainly through absorption by oceans and forests. Human emissions over this level will increase the greenhouse gas concentrations in the atmosphere, and thus, other things being equal, lead to global warming. In theory, if we cut emissions to the 4 gigatonnes level, we would go back into some natural balance.


In 1990 we were putting 6 gigatonnes into the atmosphere from burning fossil fuels and 1.5 gigatonnes from burning forests per year. Thus we needed global cuts of 46% in human emissions to keep within the 4 gigatonne level. If this reduction was obtained entirely from reductions in fossil fuel use it would require a 75% cut in burning fossil fuels.


For this reason some governmental and IPCC statements around 1990 spoke of the need for 60-80% cuts in fossil fuel burning- a figure that has since been repeated often by NGOs and the media (though very rarely by scientists). Since 1990 emissions have continued to grow alarmingly. US annual emissions alone have increased 11% since 1990. Based on the same logic, global cuts of over 50% are now needed (or 80%+ in just fossil fuels)


The logic seems simple enough, but there are assumptions behind these figures that are dangerous and deceptive:


The first assumption is that stabilising concentrations means stabilising the climate. However, it need do no such thing- the concentrations of greenhouse gases may well stabilise, but, if allowed to increase for too long, they may still condemn future generations to live in a world in which the worst effects of climate change (violent weather events, higher sea level, catastrophic ecological impacts) are a permanent feature. CO2 levels have already risen from 270 parts per million before industrialisation to 350 and there now seems little hope of preventing them from reaching 540 (a doubling on their original levels) by 2035. There is, therefore, a strong argument that we should aim for a level of emissions below the natural absorption levels so that over time we can remove the excess carbon from the atmosphere and slowly return to the climate we inherited.


The second assumption is that the capacity of the planet to absorb CO2 will remain unchanged. There is much scientific conjecture on this point- there is some reason to think that the planet’s absorption capacity is currently rising, especially from forest sequestration. However, many of the indicators are far more pessimistic in the longer term with a likely decline in absorption- widespread forest die back is expected from 2040 onwards. If we delay making real cuts for too long we could potentially find ourselves frantically chasing a target which keeps falling.


The third assumption is that all increases in atmospheric greenhouse gases will be caused by humans and therefore controllable. As climate change becomes stronger it will undoubtedly trigger the natural release of stored carbon and methane into the atmosphere from increased forest fires and melting permafrost - it may also trigger negative feedback responses that put on the brakes. The fact is that the longer we leave it, the greater will be unlikelihood of any predictable stable level of concentrations.


So for all the above reasons, we have strong grounds for thinking that we will need to aim below the “stabilising” level. What is more because the global emissions continue to rise each year, the level of global cuts required will also continue to rise. If, as seems likely, CO2 emissions will rise by 60% by 2020, overall cuts of at least 65% will be needed to achieve even the so called “stabilising” level.


WHO WILL MAKE THESE CUTS?

This brings the second point- if we can accept the need for a minimum of global cuts of 65%, who will make these cuts? The rich world created almost all the increase in atmospheric concentrations to date and per person continues to vastly outweigh developing country contributions. To call on rich countries to achieve cuts of just 65% is to assume that the current structural inequalities will be set forever- that we will ignore our responsibility and force the worlds poorest people, many of whom are in no way contributing to the problem, to also reduce by 65%.


This is completely morally indefensible. In any case, no developing nation will agree to these terms. To move forward we must recognise the principle that all people can emit equally as the basis for setting national emissions targets. If we take the 1990 population of 6 billion, emission equity would give each person an annual share of around two thirds of a tonne of carbon (to reach the global cap of 4 gigatonnes). This means that the poorest people could slightly increase their emissions on current levels. Again we have to assume that the natural capacity of the earth to absorb and process carbon is not reduced by the impacts of climate change.


It is hard to say what reductions in Britain would be required to reduce per capita emissions to the equitable level of 0.66 tonnes. According to the IPCC figures, British people emit 2.74 tonnes carbon, which would require cuts of 76%. Americans, who emit over 5 tonnes would need to make cuts of 87%. However, the official figures are distorted in two ways- they exclude air flights which are the single largest carbon item for many people; and they exclude emissions from international trade, a major item for British consumers, especially for food.


If we took the reduction as being based on the actual carbon footprint of UK people including all their direct impacts and the emissions from goods they import, the level of cut required would be far greater. Air travel alone accounts for 2% of total global emissions. However, due to the role of planes in the formation of heat trapping contrails and cirrus clouds, their climate impacts is up to four times greater than we would expect from just the carbon they burn. Considering this, and the heavy use of international air transport by UK residents, air transport adds at least 10% to emissions, and takes the needed cuts above the 80% level.


What is more, the per capita carbon allowance will fall as population increases. It is now looking very likely that world population will rise to 10 billion over this century before leveling off. A population of 10 billion would lower the per capita limit to only 0.4 tonnes carbon, assuming that the absorption capacity remains constant (it may well decline),. Allowing for this, the UK will ultimately need to reduce emissions by at least 90% on current levels to achieve per capita emissions of 0.4 tonnes of carbon..


SOME CONCLUSIONS


If we agree that:


and if we recognise that:


Then:

The UK should be aiming for minimum emissions cuts of around 90%.


If we were to accept historical responsibility for previous emissions (C02 lasts for 100 years in the atmosphere) and accept the fundamental principle of sustainability which is that we would pass on to future generations the same climatic conditions that we have enjoyed, then we would be aiming for something higher still.


IMPLEMENTATION TIMETABLE

We do not have any time left to implement these cuts- and each additional delay increases the severity of the cuts that will be needed in the future, and commits future generations to a progressively worse climatic environment.

For this reason our demand should be simple and clear- Immediate action leading rapidly to full 90% emission cuts. We should actively avoid the realpolitik of suggesting gradual implementation through interim targets (10% cut by 2010 etc). Endorsing interim targets deceives people into thinking that we still have time to act gradually. We need to strongly promote the truth, which is that the more gradual the implementation the worse the final climatic outcome- it is for society to decide the final implementation and for us to push for the fastest and hardest line we can get.


George Marshall works with Rising Tide a loose network of small groups and individuals dedicated to taking local action on climate change and building a national movement against climate change. 16B Cherwell St.,Oxford OX1 1BG UK Tel. 01865 241 097

E-mail: weathersave@netscapeonline.co.uk Website: http://www.risingtide.org.uk