The Impossible Dream of Emissions Reduction

Lowering CO2 emissions while also increasing energy consumption and GDP is an impossible dream. Emissions will at best stop increasing as long as energy consumption and GDP continue to grow.

In its World Energy Outlook 2023, the IEA (International Energy Agency) expects world GDP to double by 2050 and total energy consumption to increase but somehow the agency believes that CO₂ emissions will fall from 37 to 30 billion tons (Figure 1).

The problem with that projection is that energy consumption and CO₂ emissions have a statistically perfect, linear correlation. Figure 1 shows that the correlation coefficient R² between energy consumption and CO₂  emissions since 1800 is 0.997 (1.0 is perfect).

It is only slightly more hopeful that the correlation between energy consumption and CO₂emissions is also perfect but at least its slope has flattened over the last decade.

Figure 3. The correlation between world GDP and CO₂ emissions is statistically perfect since 1800. Its slope has changed since about 2012. Source: Our World in Data & Labyrinth Consulting Services, Inc.

Those correlations complicate the popular idea that CO₂ emissions can be substantially reduced by substituting renewable energy for energy from fossil fuels. IEA’s latest report, however, suggests that the seemingly impossible is possible—energy consumption is expected to increase +21% but emissions will fall -20% by 2050.

Coal accounted for 45% of all CO₂ emissions from combustion activities in 2022 and 71% of emissions from coal are from electric power generation (Figure 4). That is the best explanation for why climate-change efforts are focused on power generation even though electricity accounts for only about 20% of world energy consumption.

I am going to simplify analysis by initially limiting discussion to electric power.

IEA’s reference case Stated Policies Scenario suggests that renewable sources will increase from 29% of total electric power in 2022 to 70% in 2050, and that generation from coal will fall from 36% in  2022 to 9% in 2050 (Figure 5). Electric power generation will increase 86% from 29 terawatt hours (TWh) in 2022 to 54 TWh in 2050. Electricity will increase from 20% to 30% of total final consumption by 2050.

As a consequence, IEA expects that coal consumption will fall -7.5 exajoules (EJ) and that its CO₂ emissions will decrease -6.5 gigatons (Figure 6). In its recently published International Energy Outlook 2023, the EIA (Energy Information Administration) disagrees. EIA projects that coal use will rise +2.3 EJ, and that coal emissions will increase +0.6 gigaton by 2050. The difference in CO₂ emissions between those forecasts is +7.6 gigatons! EIA’s projection seems more reasonable based on the historical correlation between energy consumption and emissions (Figure 2).

At the same time, global carbon emissions have flattened as renewable energy capacity has increased but this required a four-fold average annual increase in renewable capacity since 2012 (Figure 7). Expenditures are estimated at more than $3 trillion over the last decade.

Limiting the increase in carbon emissions from energy use is an important step in the right direction but a solution for climate change requires more.

IEA and EIA CO₂ data includes only emissions from energy combustion. Total CO₂-equivalent emissions including land-use change, methane and nitrous oxide has averaged about 17 gigatons (+52%) more than reported CO₂ over the last 20 years (Figure 8).

I do not mean to disparage progress or to imply that efforts to address climate change are a waste of time. On the contrary, IEA and EIA have provided valuable new data that helps evaluate the present state of those efforts. At the same time, there is no path forward toward reduction of carbon emissions that does not include limiting energy consumption and economic growth.

I am not optimistic that this will occur voluntarily. It will happen because the planet is a system that will self-organize around its own needs if society cannot see beyond its own selfish interests.