Decarbonising the world: a dead horse flogging itself?

Pierre Aury questions whether we have our priorities right when it comes to making the world a greener place.

The Marine Environment Protection Committee had its 81st meeting last month. In a strange case of perhaps the first documented instance of a dead horse flogging itself, shipping has embarked on a crusade to become the only industry in the world that can decarbonise itself fully and quickly! But first the big picture.

The graph shows world CO2 emissions rebased at 100 in 1960 in blue (LHS) and the CO2 concentration in the atmosphere also rebased at 100 in 1960 in red (RHS).

Funnily enough, we have a fixation on the absolute number of tons of CO2 emitted annually when in fact what matters is the concentration of CO2 in the atmosphere which is what is responsible for global warming.

The problem is that 50% of the CO2 emitted will stay more than 120 years in the atmosphere. As can be seen in the graph above the dramatic reduction of emissions due to covid is not reflected in the concentration curve. The concentration of CO2 in the atmosphere will only start to go down the year we emit less CO2 than what disappear naturally from the atmosphere. Taking a half-life of 120 years means that every year about 0.4% of the CO2 present in the atmosphere is disappearing (50/120=0.41) when our emissions have been increasing at a compounded rate of 1.3% per annum over the last 30 years…simple but cruel maths.

In a nutshell all this decarbonising of our economy is indeed the right solution, but will only show results in the long term. Is this the first instance of politicians doing something for a long term gain? Intriguing as well is the fact that the decarbonising framework which is put in place is implicitly based on a fairy tale which goes along these lines. A long time ago human beings were burning wood. Wood was then replaced by coal which in turn was replaced by oil and gas. So we are just about to see a repeat of that phasing out/ phasing in process with now zero carbon or net zero energies about to replace oil and gas. Simple, no? Simple, yes but untrue. Humanity has never burnt more wood than now. In fact, every time a new source of energy appeared it did not replace the previous one, it actually catered for new uses. This phenomenon, known as the rebound effect, also called the Jevons paradox, is well documented over the centuries.

But let us go down now to the sector level. The pie chart below shows selected sectors with their relative share of global CO2 emissions:

Two sectors together account for more than 50% of global emissions: electricity generation and agriculture together cover 53% of all emissions. Add cars and vans and you have 60% of all emissions. Now using, again, simple maths, a decrease of 10% of the emissions of the electricity generation sector would be more than a decrease of 100% of the emissions of the shipping sector. A decrease of 10% of both the electricity generation and agricultural sectors would be more than a decrease of 100% of the emissions of the shipping and aircraft sectors together.

A 30% decrease of emissions of cars and vans would equate to all emissions of the shipping sector. We know how to cut car emissions by 30% – just go away from two tons or more cars to one ton cars as we used to have not so long ago which we are nowhere near to be doing while at the same time we are kitting dry bulkers with kites.