Auteur : Agence Science Presse - Maxime Bilodeau
The lockdown has caused an historic drop in greenhouse gas (GHG) emissions. But this represents only a small fraction of what we emit. Involuntary efforts made this GHG reduction possible. They teach us three things about the efforts still required to fight the climate crisis, the Rumour Detector explains.
1) Half of humanity was on a “break”. Where do the greenhouse gas (GHG) emissions come from despite the Great Lockdown?
Researchers estimated GHG emissions from January to April in a study published on May 19 in Nature Climate Change. The study covered 69 countries representing 85% of the world’s population and 97% of global emissions.
Their analysis shows sharp drops in GHG emissions from surface transportation (-50% compared to the equivalent average in 2019) and air transportation (-75%). In fact, the decrease in transportation needs is the source of the biggest reductions due to the lockdown. Telework and the closing of borders to travellers explain this in turn. Surface and air transportation respectively accounted for 20.6% and 2.8% of GHG emissions in 2019, according to the authors.
Lower electricity production also accounts for a reduction of GHG emissions. But this drop is less radical (-15%). While offices were closed, they still had to be heated. In the meantime, residential power consumption increased by 5%, driven by the lockdown. Electricity production was the leading GHG emitter in 2019. It had a relative weight of 44% of emissions. Remember that for much of the planet, electricity still comes from fossil fuels.
Finally, the industrial sector’s GHG emissions decreased by 35%. The industrial sector includes production of materials and all manufacturing activities. This figure represents maintenance of economic activities considered essential despite the imposition of confinement measures. Industrial activity was the origin of 22.4% of global GHG emissions in 2019.
Reduction of CO2 emissions per sector, January to April
From left to right: electricity, industry, transportation (Nature Climate Change)
2) Does the year 2020 guarantee that GHG reduction targets will be met in the future ?
Estimates vary, but experts agree that all this could translate into an historic drop of 4% to 8% of GHG emissions over the entire year 2020. This may seem low compared to the reductions of 15% to 75% mentioned above, depending on the sector. But remember that these 15% to 75% reductions are only valid for the first four months of the year. The final balance for 2020 will depend on the rhythm of the return to normal economic activity. The later this happens, the bigger the global decreases will be.
But the international community would have to reduce GHG emissions by 7.6% per year from 2020 to 2030 to honour the commitments made in the Paris Climate Agreement. The Annual Report of the United Nations Environment Program noted this fact last fall.
In other words, we’ll have to maintain a GHG rhythm similar to the possible decrease due to the lockdown in 2020. That’s if we want to limit global warming to 1.5 degrees Celsius by 2100. According to the study published in Nature Climate Change, a massive shift to green energy to produce electricity seems to be essential to meet these goals.
3) Is Québec any different in reducing its GHG?
Québec isn’t in the same position, because its electricity doesn’t come from fossil fuels. Its reduction of GHG emissions since the beginning of 2020 may reach 10.3 million tonnes of C02 equivalent GHG by the end of the year. Le Journal de Montréal reported this in May. The reduction is explained by a slowdown of industrial activity and a sharp decrease in automobile traffic. The province is on the right track to meet its 2020 GHG reduction target. This wasn’t the case just before COVID-19.
The transportation sector weighs heavily in the balance of Québec GHG emissions. In 2017, road, air, marine, rail and off-road transportation generated 43.3% of its GHG emissions. Road transportation alone accounted for nearly 80% of transportation emissions, or 34% of total GHG emissions. Industrial activity ranked second, with 30% of GHG emissions.
It’s normal for a slowdown of these two sectors in 2020 to improve Québec’s annual environmental balance just as quickly. But it’s still unknown if this projected reduction of GHG emissions in 2020 will be repeated in the years ahead… or whether it will be a historical anomaly due to the Great Lockdown.