For more than thirty years scientists have been warning that one of the prominent features of climate change, apart from warming, will be increasing severity and frequency of extreme weather events. Climate results from a very complex interaction of many factors making it impossible to tie any single event such as the present NSW bushfires to human generated carbon emissions. However, the bushfires are consistent with the models which have been the basis of the warnings for thirty years. It would be harder for deniers like our PM to prove that the severity of the fires is not linked to human induced climate change.
It would be wise to accept that the severity of the fires is linked to climate change and that continuing and exacerbating this change will make the situation ever more hazardous. What then do these fires indicate for longer term strategies?
Large amounts of CO2 and other greenhouse gases have already been emitted into the atmosphere leading to a general warming. But there is a considerable latency in the climate system. The CO2 already there will not exert its full warming potential for many decades. Humanity has committed itself to further warming even if emissions were stopped today.
The only safe level of CO2 in the atmosphere that we know of lies between 180 and 300 ppm, the levels between which CO2 fluctuated during the whole 6 million years of human evolution from our last common ancestor. Humans, through the burning of fossil fuels, have pushed this to ~400 ppm, right outside this range. It is unlikely that any increase outside this 6 million year range will be benign. More additional CO2 will be more damaging than less.
Bearing this in mind the IPCC and other scientists have suggested that a 2⁰C rise in temperature marks a limit beyond which it is unsafe to venture. Not that this is a ‘safe limit’. Indeed Professor Kevin Anderson has described 2⁰C as ‘the threshold between dangerous and extremely dangerous’. Some have suggested a lower limit of 1.5⁰C which relates to lower allowable levels of CO2 such as 350 ppm. For example, to have a 93% chance of staying below 2⁰C CO2 levels should stay below 350 ppm. These figures have important policy implications very relevant to Australia. For Australia is amongst the world’s highest per capita emitters of greenhouse gases and also one of the world’s largest coal exporters.
The IPCC and other scientists have calculated the total amount of CO2 that could be put into the atmosphere and still have eventual warming below an average of either 2⁰C or 1.5⁰C. When one subtracts from this the amount that has already been poured into the atmosphere one is left with the potential additional amount that humanity could emit from now into the far future and still stay below these limits. Estimates of this amount vary from zero to 500 Gigatonnes, the lower figure being predicated on a view that 2⁰C of warming may still have unacceptable and serious consequences.
Whichever figure is taken the conclusion for humanity is clear. A rapid phase-out in fossil fuel use is imperative. It is not possible to run up to a carbon emission limit and then suddenly stop. There is more than enough known sources of fossil fuels to exceed these limits. The phase-out applies to three areas.
We must desist from any further exploration for more fossil (carbon based) energy. The recently announced expanded exploration for oil in the Great Australian Bight or for gas in the Cooper basin is not only a foreseeable crime, both represent an enormous waste of financial and material resources that should be directed elsewhere. Those who pursue this exploration and governments that allow it, encourage it or licence it, are guilty of a serious crime against their fellow humans. Those who have lost homes and loved ones in recent fires take note!
The issue of use of material resources mentioned in the previous paragraph is important for one of the critical resources is fossil fuels. We currently live in an economy dominated by dependence on fossil fuels. As we have seen the amount of these that can still be burnt is very limited. We should not be expending any of this precious energy looking for more but rather for building the alternative and renewable sources needed to sustain civilisation.
Secondly, we should stop any exploitation of known fossil fuel reserves that have not yet been mined. They should be left in the ground.
Thirdly, we should then move on to phasing out exploitation of those fossil fuel resources already being mined reserving what is mined for the purposes of the transition to renewable energy sources. Only through a rapid phase-out in the use of fossil energy, meanwhile building renewable sources of energy can we stay within even the upper limit.
These strategies have become inevitable. Those who fail to admit this fact and continue to pursue policies that serve their own short-term selfish interests must be held legally liable.
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