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A glass half full . . .

Following on from my previous post, I spoke at the opening lunch of Singapore Energy Week on the same subject  – a trillion tonne carbon budget. The core of the story went something like this.

The starting point is a trillion tonne “glass”, now just over half full with industrial revolution carbon (data from IEA and CDIAC), coming both from fossil fuels and deforestation (in reality it is probably worse than this as my simple analysis did not include the other greenhouse gases). The world is filling the “glass” at an increasingly rapid rate and it is now over half full.

If the world continues to fill the “glass” through to 2100, with emissions growing at 1% per annum (as an example – but energy related CO2 emissions have increased at 2% p.a. over the last 40 years – but have dropped by some 3% in the last 12-18 months) then we end up with some two trillion tonnes of carbon emitted since 1750, well above the trillion tonne level that equates to a 50% chance of hitting 2 degrees C – in other words, “two glasses completely full” and a world quite a bit warmer than 2 degrees C.

In reality, the current global hydrocarbon reserve picture does not fully support such a simple proposition. Using the oil, oil-sands, gas and coal reserves data in the BP Statistical Review of World Energy 2009 and assuming that all those reserves are consumed, together with assumptions on the growth in cement manufacture  and continued land use change, the carbon situation looks more like this – two “glasses”, each not quite full.

I then turned attention to solutions with a focus on the largest overall contributor, coal. Today there is some 1000 GW of coal fired power generation, producing about 8 billion tonnes of CO2 per annum. According to the International Energy Agency, emissions are growing at 6% p.a.  The chart below shows growth is accelerating rapidly in China, but also in the rest of the world outside North America.

If we assume that emissions from coal fired power stations double by 2050, then plateau for the remainder of the century, then this alone fills the trillion tonne “glass” from where the world is today. Coal reserves can more than support such a move although it will be a challenging level of production.

One approach is to look to carbon capture and storage  (CCS) for a solution.  CCS represents a safe and sustainable approach for dealing with CO2 emissions and is based on a family of technologies all in use today. Although large scale end-to-end demonstration needs to happen urgently, deployment need not be some distant dream.  As a thought experiment, what if we started building all new coal fired power stations with CCS and either retrofitted with CCS or replaced all existing coal fired power stations by 2050. The global carbon story through to 2100 would change radically and look something like this – a “glass and a bit”, so still not there, but a huge improvement.

This is a pretty heroic assumption, but nevertheless points toward a solution, or at least part of it. In reality we have to do much more, but the focus need only be in five areas. They are;

  1.  More efficient use of the energy sources that are available;
  2.  Increased use of renewable and nuclear sources for the provision of energy;
  3.  Carbon dioxide capture and geological storage in tandem with the use of fossil fuel sources for the provision of energy [or with the chemical conversion of fossil derived materials for the provision of various manufactured products];
  4.  Containment, destruction and reduced usage of greenhouse gases other than carbon dioxide;
  5.  Reducing emissions through land use, land use change and forestry, including reducing emissions from deforestation and degradation.

I concluded with some discussion on the policy measures necessary to do all this, which I have discussed in many previous postings.

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