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Climate roulette

roulette fin.jpg
Is the climate gun already loaded?

By James Dacey

Mankind is playing a Russian roulette with the climate, according to a study published today in the Proceedings of the National Academy of Sciences.

Elmar Kriegler of the Potsdam Institute for Climate Impact Research and his colleagues sought to find out what leading scientists really think will happen to the climate.

So Kriegler surveyed 43 scientists to gauge the impact of rising temperatures on five major components of the global climate system.

They calculate a one in six chance that a “tipping event” will occur if the temperature increases by two to four degrees in the next two hundred years.

The five systems concerned are:

Major changes in the North Atlantic Ocean circulation
The Greenland and West Antarctic ice sheets
The Amazon rainforests and El Nino.

They define a tipping point as “the event of initiating the transition, or making its future initiation inevitable”. Essentially they are saying that beyond these points the climate will reach a kind of elastic limit – beyond which, we will feel the wrath of the climate and there’ll be nothing we can do about it.

Realising that previous surveys have been met with a fair degree of apathy they used “imprecise probabilities” – a part of Bayesian statistics.

This new mathematics has been controversial but advocates say it can weigh up a given hypothesis in a more rounded way than classical statistics.

Developed in the 1980s and 1990s Bayesian statistics seem to have gained most traction in the field of operations research and economic decision making.

“The currently discussed long-term targets of 50% reduction globally by 2050 (and 80% reduction for the industrial countries), with a continuing reduction after 2050 is an important step in this direction, but does not guarantee the reaching of the 2 degree target,” Kriegler told

This may sound like a very gloomy forecast but Kriegler was a bit more pragmatic about taking co-ordinated international action:

“Nevertheless, these [targeted reductions] are a useful benchmark to focus the minds of politicians and society. Reaching this goal requires at least the following – in the order of importance:

1) A massive decarbonisation of the energy system, starting in the electricity sector;
2) A strong increase in energy efficiency;
3) A stop to tropical deforestation, and an increase of the forest area in the tropics in the long run;
4) A massive reduction of CH4 and N2O emissions from the agricultural sector.”

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  1. Terry W. Brookman

    YES! Your timing is all wrong as climate change is happening much faster than most think. There are more factors involved as positive feedback increases, you should also factor in subsurface heat blooms.

  2. Timray

    Hmmmm….making statistics reach the conclusion you want…how novel.

  3. Nick Cook

    In developed countries about 30% of the energy budget is used for transport. By converting to predominantly electric (land) transport the energy budget for this could be cut by about 75%, compared to current usage. Furthermore, if this energy is supplied from ‘green’ electricity this would take about 30% out of our CO2 emissions at a stroke. Apart from gross energy requirement reduction direct solar electricity is about the most efficient way of collecting solar energy.
    For example, about 3 sq-m of CPV solar panel (possibly less) in the Sahara Desert could provide enough electricity to run a family sized BEV doing about 10,000 miles/ 16000Km per year. On the other hand, powering a conventional car with liquid biofuel would require upwards of a thousand, probably several thousand, sq-m of land to produce enough biomass energy. For comparison people need about 2.3KWh/day (2,000Kcal) which requires a minimum of 200 sq-m/person if all you eat is potatoes, realistically 500-1000 sq-m. The logic/maths is quite simple; sunlight to electricity conversion efficiency for CPV is ~35%, but sunlight to biofuel via photosynthesis

  4. Playing Russian roulette with with phenomena that have longer time scales than our economic time scales is common in organisations.
    I work in the area of Disaster Recovery, most of our clients come to us because they have already had a disaster.
    Even when top management has approved a DR plan, implementing it within the organisation is met with significant resistance fueled by self interest and ignorance.
    If humanity behaves like a typical organisation, then we will go over a ‘tipping point’ before we recognise and act on a significant risk event.
    When we do finally decide to act, implementing an agreed climate plan will be met with resistance, ignorance and self interest.
    Perhaps the to best course of action is to leave the planet, following the dolphins lead from Hitch Hikers Guide the Galaxy: “so long and thanks for all the fish”.


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