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Before you can develop the solution,
you must first understand the problem you are trying to solve.
What are we trying to achieve?
The step in defining your goals is to work out what outcomes you are trying to achieve. For me this preventing a run away climate event in order to preserve as many people and species as possible and in achieving this goal ensure we develop a series of environmentally and socially sustainable systems across the globe.
Once we have defined what we are trying to achieve we can then try and define goals and targets to meet these outcomes. The two critical goals we therefore need to define are:
- what level of greenhouse gases in the atmosphere must be reached in order to prevent a run away climate event? and
- how fast should we seek to achieve this level?
The 300 Goal
Common Sense Science
We looking at what level of greenhouse gas might be an appropriate level for is to look at the historical levels of greenhouse gases which provided humans with similar climates that we have experienced today.
This approached was used by a number of zero emission activists including myself to justify their calls for zero emissions targets for some time and in my case as far back as 2003.
Brendan Mackey, from Australia National University sums up the logic this approach in his recent paper "Green Carbon - The role of natural forests in carbon storage", Mackey et al.2008
"What constitutes a 'safe level' is a critical question that is being debated actively among scientists and policy advisers. Evidence from glacial ice cores has revealed that atmospheric concentrations of carbon dioxide ranged between 180 and 300 parts per million by volume (ppmv) in the past 650 000 years (with typical maximum values of 290 ppmv) (Petit et al. 1999; IPCC 2007). Assuming this natural variability revealed by the ice-core records persisted, we should assume a maximum safe level is 300 ppmv." (Mackey 2008)
Tipping Points Based Science
Another way to look to define the atmospheric concentrations we are looking at what are the levels at which critical climate stabilisation systems pass their tipping points. This approach is quite scientifically complex requiring a detailed understanding of how climate systems works and have worked in the past, effectively requiring you to be an expert in the field.
James Hansen, NASA's chief climate scientist, uses this approach in his recent paper paper titled "Target Atmospheric CO2: Where Should Humanity Aim?". He suggests in this paper that atmospheric greenhouse gas concentrations of between 300-325 ppm CO2 are required to achieve the refreezing of the Arctic summer ice. As we don't know exactly where the safe level is within the 300-325ppm CO2 range the concentration we need to aim for is the lower end of that range or 300ppm CO2.
If it happens that the the Arctic summer ice refroze on the way down to a 300 ppm CO2 level we could stop there, however there are a number of other critical climate stabilisation systems that pass tipping at or above 300ppm CO2 level so until the science suggests otherwise 300ppm
This issue and Hansen's work is discussed more comprehensively here.
The Zero Emissions Minus Goal
“There is too much greenhouse gas in the air NOW! There is absolutely no advantage in having any more in the air, NOW! Our private targets should be to have no future emissions into the atmosphere. That's what we really need. Philip Sutton, Melbourne Social Forum, conference, March 2007
The phrase “Zero Emissions Minus” describes the goal of reducing human greenhouse gas emissions to close to zero(i) in order to reduce our emissions below the level of natural sequestration / decomposition of greenhouse gases. When this point is reached, natural systems will be sequestering more carbon than is being released into the atmosphere – therefore levels of atmospheric greenhouse gases will reduce.
Currently natural sequestration is estimated to occur at around 4 billion tons (Gt) of carbon a year. Higher temperatures are expected to seriously reduce the natural sequestration rate by mid-century. One estimate is that it will reduce to 2.7 Gt per year by 2030.
Let’s say we choose a figure of initially reducing atmospheric greenhouse gases by 3 Gt of carbon a year, then we are left with only 1 Gt of allowable carbon emissions to distribute across the entire world population to deal with meeting emissions that have not yet been reduced to zero.(ii)
The world population is 6.5 billion and by using the principles of equitable global carbon rationing(iii), where allowable carbon emissions (1 Gt) are divided up on a per capita basis, Australia would be allowed to produce O.15 tC per person or 3.1 million tons (Mt) of carbon (11.4 Mt of CO2) as a nation per year.
We currently produce 564.7 Mt of CO2e (2004 figure), and therefore we would need to reduce today's greenhouse gas emissions by 98% to meet our allowance of 11.4 Mt of CO2e.(iv)
Human assisted sequestration would be used to maximise the rate of atmospheric GHG removal.
To put these figures in the context of the standard “X% of 1990 levels by 2050”, it would mean Australia must reduce its carbon emissions by 98% on 1990 levels. This assumes a world population of 9 billion and a continued shared desire to produce no more than 1 Gt of carbon per year globally with all nations moving simultaneously to reach similar carbon rationing based targets.
Even if we merely wanted our emissions to be “Net Zero” or “Carbon Neutral”, i.e. having no net effect on atmospheric GHG levels we would still need to reduce our current GHG emissions by 92%, and we would be resigning ourselves to climate impacts worse than we already see today, because of the additional 0.5-1.5º temperature rise already built in.(v)
(i) In reality we might only get an outcome of 97-100% reduction in different sectors, but note the 97% figure is not the goal but an outcome of working towards a 100% zero emissions goal.
(ii) The decision to reduce atmospheric CO2 by 3 Gt per year is largely an arbitrary decision on my behalf and in reality should be as high as we can make it. It must be supplemented by human assisted sequestration to maximise the rate of atmospheric GHG reduction. Food production would be expected to utilise a significant proportion of the allowable GHG emissions.
(iii) The question of compensation for the damage to the world climate systems by the developed nations (who are responsible for releasing most of the GHG from fossil fuel burning and deforestation) is still not dealt with by the carbon rationing system. The developed world must pass on and fund the roll out of zero emissions technologies, prevent further land clearing and aid in adaptation programs for developing nations. A non carbon based economy needs to be established in the developing world as ultimately the carbon economy has no future. Investment in carbon economy technology for the developing world would only disadvantage them in the long run and slow the global move towards zero emissions.
iv) I have converted our allowable CO2 emissions directly into an allowable CO2e or “carbon equivalent” figure. This allows a comparison against the figure for total GHG emissions in CO2e from Australia's GHG inventory but ignores in the initial calculation of allowable emissions the natural sequestration or decomposition of other GHGs, most notably methane which only has an average life of 12 years in the atmosphere. If we restricted our analysis to purely CO2 emissions, the figure for CO2 released in 2004 is 415 Mt CO2 which would require a 97.25% reduction in our CO2 emissions to still restrict global emissions to 1 Gt C per annum. If we wanted to tread water (in the ever rising seas) and go for “carbon neutral” looking at CO2 only, then we would need to reduce today's CO2 emissions by 89% immediately (calculation below).
Natural carbon sequestration of 4Gt of carbon per annum divided by a world population of 6.5 billion gives us .615 t C per capita per annum, multiplying this by Australia's population of 20.25 million gives us an annual figure of 12.46 Mt of carbon which can be released into the atmosphere. Multiply this by the carbon to carbon dioxide weight conversion factor of 3.6675 gives us a total annual figure of 45.7 Mt of CO2 allowable for release into the atmosphere. Converting this figure to a percentage of our total CO2 released per year (451.05 Mt , or 45.7/415.05*100) gives us a goal of 11% of CO2 emissions or an 89% immediate reduction.
(v) The 92% carbon neutral figure would increase in size each year we delay reducing our emissions, and would also have to increase over time as the earth's natural systems lose their ability to absorb atmospheric carbon, a process which is occurring now.
The 10 years goal or as fast as possible.
“How long? Not long, cause what you reap is what you sow. Wake Up”
Rage Against The Machine
Those advocating strong and even not so strong action on climate change typically say we have 10-20 years to make significant changes to our Greenhouse gas emissions. This approach is logical given the extreme complexities around this issue and the still developing science around tipping points and climate systems and the potential if we wait much longer we may not be able to turn the problem around.
The 10 year goal also seems a reasonable estimate of the time it may take to rebuild critical systems within our society such as transport,stationary energy and agriculture if we adopted a climate emergency response.
Given some scientists such as James Lovelock who believe we have already passed the point of no return and we are now destined to experience “...the greatest die-off humanity has ever seen...We will be lucky if 20% of us survive what is coming. We should be scared stiff.” (Leake 2007), the lay climate advocate has little choice to follow the lead of others within the climate movement and likewise call for major change to be implement within a 10 to 20 year time frame and strive so that humanity can respond effectively.
The alternative is to join the Love Lock camp and live out the collapse of our society in what ever way you see fit.
The bottom line is the faster we can make the changes the better chance we have avoiding a runaway climate scenario, and the more urgency we place on the speed of our response the greater the likelihood that broad acceptance for need for change will occur earlier.
References
Leake, J 2007, Fiddling with figures while the Earth burns, TimesOnline, 6 May, viewed 15 September 2008 http://www.timesonline.co.uk/tol/news/uk/science/article1751509.ece
300 ppm CO2 or below is the stabilisation target for a safe climate.
