A recent paper by The International Renewable Energy Agency attempts to quantify what a decarbonized economy might look like. The report compares energy use and CO2 emissions to show what 12 major economies might look like in 2050 if they cut their carbon dioxide emissions by 80 percent.
The findings show the challenges ahead to make deep cuts in emissions, and highlights that many countries are already reducing emissions.
They conclude that such a target is technically and economically feasible, but it would mean significant changes in how we live and do business.
Carbon Dioxide Emissions
The report examined the effect of steep reductions in CO2 emissions on energy use and the economy.
Global greenhouse gas emissions will increase from 46 billion tons to 65 billion tons on a business-as-usual trajectory by 2050.
A substantial reduction in emissions that hold warming below 2°C, would reduce global greenhouse gas emissions to 21 billion tons by 2050 [81% less than business-as-usual trajectory].
Energy Use and GDP
Cutting emissions by 80 percent would reduce global energy use by roughly 37 percent. This is because a lack of carbon-based fuels would require more efficient energy use and a switch to renewables.
In all 12 countries studied, GDP growth was larger than energy use growth. This means that countries could reduce emissions while at the same time growing their economies.
However, if economic growth outpaces emission reductions due to more efficient energy use, CO2 emissions would flatline or even rise slightly between 2020-2050 in many countries.
Even with rapid decarbonization, electricity generation accounts for only 20-40% of total primary energy demand by 2050 in all 12 countries studied. This is because widespread electrification of end uses, like heating and transport, offsets the gains made through switching to low carbon energy sources like renewables or nuclear power.
For example: In the USA, 80 percent of heat demand would be met by a combination of heat pumps and biomass fuels [70%] or natural gas [10%] in 2050.
In some countries, oil use continues to grow but at a much slower rate than current trends – due to greater fuel efficiency from electric drivetrains.
A Reversible Trend?
The report suggests that getting emissions down to 80 percent below 1990 levels is definitely possible but we still can’t tell if decarbonization is sustainable and at what cost.
It could be reversible, just like we’ve seen in historical examples of technological change [for example, coal]. Technology development drove down emissions by increasing energy efficiency and reducing costs for renewables, which allowed emissions to grow again without much government intervention or legislation.
The study discusses various sources of emissions to examine how economic growth, energy use and the energy mix changes with rapid reductions in emissions. However, it does not discuss land use [deforestation] or agriculture, which are important sources of greenhouse gas emissions. And it also omits black carbon [soot], another major threat to global climate stability with local impacts.
The report also does not quantify the social or environmental impacts of decarbonization – for example, how changes to energy use might affect employment levels in various sectors. Nor does it discuss the possibility of negative emission technologies [carbon capture & storage].
Rapid reductions in carbon emissions are technically feasible, but they will require an overhaul of our energy systems and lifestyles. This would be an incredible challenge, but we knew that already. This is why we need ambitious climate policy and technology pushing us forward towards a clean energy future, rather than just sticking with business as usual or becoming pessimistic about the challenge. The good news is that such rapid emission cuts mean that economic growth can continue uninterrupted.