- Pierce Forster *
- Special for BBC Future
Attributed to him, Getty Images
The planet has already warmed by about 1.2 ° C since the pre-industrial era, when the World Health Organization (WHO) officially declared a pandemic on March 11, 2020.
This led to a sudden and unprecedented decline in human activity. With most of the world closed, factories ceased operating, cars stopped for long periods and planes stopped flying.
Many tremendous changes have occurred since then, but for us, climate scientists, this period also brought some completely new ideas.
And often, it’s unexpected.
Here are three things we learned:
1. Climatology can work in real time
The pandemic has made us think about how to overcome some of the difficulties of monitoring greenhouse gas emissions, and carbon dioxide in particular, in real time.
When several shutdowns began in March 2020, the global carbon budget, which sets emissions trends for this year, will not be released until the end of the year.
Therefore, climate scientists are starting to look for other data that could indicate changes in carbon dioxide emissions.
We use the information about the lockdown as a mirror to global emissions. In other words, if we knew what emissions were from different economic sectors or countries before the pandemic, and we knew how much reduced this activity was, we can assume that their emissions have decreased by the same amount.
In May 2020, a benchmark study combined government shutdown policies with activity data from around the world, and forecast a drop of up to 7% in carbon dioxide emissions by the end of the year, a figure later confirmed by the Global Carbon Project.
This was soon followed by research by my team, which used navigation data from Google and Apple to analyze changes in 10 different pollutants, while a third study again monitored carbon dioxide emissions using fossil fuel combustion and fuel production data. Cement.
Google’s latest mobility data shows that while daily activity has not yet returned to pre-pandemic levels, it has recovered somewhat.
This is reflected in our latest emissions estimates, which, after the limited recovery after the first shutdown, show very stable growth in global emissions during the second half of 2020.
Attributed to him, Getty Images
Although emissions may have decreased due to airlines suspending flights, the lack of air traffic may have caused a slight rise in temperatures.
This was followed by a second slight decline, represented by the second wave in late 2020 and early 2021.
Meanwhile, as the pandemic has progressed, the Carbon Watch project has created ways to monitor carbon dioxide emissions in nearly real time, providing us with a valuable new way to do this kind of science.
2. No significant impact on climate change
In the short and long term, the pandemic will have less impact on efforts to combat climate change than many people expected.
Despite the clear and calm skies, the research I was involved in showed that the lockdown had a slight heating effect in Spring 2020: as the industry stagnated, air pollution decreased as well as the capacity of aerosols, and fine particles from burning fossils. Fuel, to cool the planet by reflecting sunlight away from Earth.
The effect on global temperatures was short-lived and very small (an increase of only 0.03 ° C), but was greater than any other impact due to changes in ozone, carbon dioxide, or flight associated with reservation.
Looking ahead, for 2030, simple climate models estimate that global temperatures will be only about 0.01 degrees Celsius lower as a result of the COVID-19 virus than if countries had fulfilled emissions pledges that were already in place at the height of the epidemic.
These discoveries were later supported by simulations of more complex models.
Many of these national pledges were updated and strengthened last year, but they are still not sufficient to prevent dangerous climate change, and as long as emissions continue, we will consume the rest of the carbon budget.
The longer we take action, the more obvious the need to reduce emissions.
3. This is not a climate action plan
The temporary disruption of normality that we have now seen with successive lockdowns is not only sufficient to prevent climate change, it is also unsustainable: like climate change, the COVID-19 virus has severely affected the most vulnerable.
We need to find ways to cut emissions without the economic and social impacts of lockdowns and find solutions that also boost health, well-being and equality.
Attributed to him, Getty Images
Shutting down the global economy is not a practical way to reduce carbon emissions
The spread of climate ambition and the interference of individuals, institutions and companies are still vital, but they must be sustained and supported by structural economic changes.
My colleagues and I estimate that investing just 1.2% of global GDP in economic recovery packages could mean the difference between keeping the global temperature rise below 1.5 ° C and the future in which we will face more serious impacts – and higher costs.
Unfortunately, green investment is not made at the necessary level. However, many other investments will be made in the coming months.
It is imperative that strong climate action be combined with future investments. The stakes may seem high, but the potential rewards are much greater.
* Pierce Forster is professor of the physics of climate change and director of the Priestley International Climate Center at the University of Leeds, United Kingdom.
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