At the same time, the relative size of the energy sector as a function of the whole economy has shrunk, from a dominant contribution (especially if we regard food as a fuel) to just 9% for the energy and 3% for the food sectors in developed countries today, for example Sweden (Figure 3).
Energy is the essential driver of modern civilisation. World GDP this year is estimated at $88 trillion, growing to $108 trillion by 2023, with the energy sector then being of order $10 trillion. But renewables have played, and will continue to play, a peripheral role in this growth. Industrialisation was accompanied by a steady and almost complete reduction in the use of renewables (Figure 4).
Then, in response to the oil crises in the 1970s, there was a big increase in research into wind and solar photovoltaics, as the US tried to wean itself off dependence on foreign fossil fuels, but this had little impact on the economy, and the pressure to achieve energy independence waned during the 1980s, although R&D continued. In recent years, there has been an uptick in renewables use, but this has been entirely the result of the pressure to decarbonise the global economy in the context of mitigating climate change, and the impact has again been nugatory. Modern renewables remain an insignificant share of the energy supply (Figure 5). Indeed MIT analysts suggest the transition away from fossil fuel energies will take 400 years at the current rate of progress.
In order to keep global temperatures to within 1.5◦C of pre-industrial levels, we intend to eliminate emissions of greenhouse gases (mainly carbon dioxide) by replacing all the energy developments since about 1880 with zero-carbon alternatives. This is to be achieved by 2050. Figure 6 shows the scale of what has been proposed. Even reaching the old target of an 80% reduction in carbon dioxide emissions would be miraculous; this is a level of emissions not seen since 1880. I assert that a herd of unicorns will be needed to deliver this target, let alone full decarbonisation. I also point out the utter nonsense of Extinction Rebellion’s demands to complete the task by 2025.
Contemporary drivers of energy needs 1995–2035
I wish to focus on the drivers of global energy demands today by looking back and forward twenty years. Figure 7 shows data from BP covering the period 1965–2035 on the demand for global energy by fuel type. The data to 2015 is historic and not for challenge.
One notes that we have not had an ‘energy transition’: fossil fuels have continued to grow steadily at a rate about 7–8 times that of renewable technologies over the last 20 years. The energy demand of the major developed countries has been static or in small decline over that period. Most of the increase has come from growth in the global middle class, which increased by 1.5 billion people in the 20 years to 2015. The World Bank is anticipating a further increase of 2.5 billion by 2035, much of it the result of China’s Belt and Road Initiative, and BP estimate a further 40% growth in global energy demand by then. The whole of Figure 7 can be explained quantitatively if one assumes that a middle class person (living in a high-rise building with running water and electricity, without any mention of personal mobility – the World Bank definition of middle class existence – uses between three and four times the amount of energy per day as a poor person in a rural hovel or urban slum. You should be under no illusions: this is a humanitarian triumph. It is the delivery of the top Sustainable Development Goals – the elimination of poverty and hunger – that has been and will remain the main driver of energy demand for the foreseeable future.
And this improvement in human welfare will be driven almost entirely by fossil fuels. BP suggest that by 2035, renewables will still only be delivering about 10% of energy demand, less than one sixth of fossil fuel provision. And one sees a smooth evolution rather than any break points that would indicate major advances or abrupt changes in the energy sector.
Decarbonisation progress to date
In the UK, the Climate Change Committee has, on the face of it, overseen a steady fall in UK emissions of carbon dioxide since its formation in 2008. However, the fall started in 1990 and has continued at a very steady rate since (Figure 8a).