Discoveries

November 30, 2023

The Weekend Shift

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While most people get to rest on the weekend, plants work harder. Satellite data showed that human activity could be linked to levels of photosynthesis made by plants, and their capacity to hold carbon dioxide, reported New Scientist.

Photosynthesis is a chemical reaction through which plants capture light from the Sun and CO2, and release sugar.

A group of researchers measured how much plants in Europe were photosynthesizing from 2018 to 2021 by looking at satellite measurements of light emitted by plant leaves – specifically, their green pigment called chlorophyll.

They analyzed these data and compared them with measurements of air pollution over the same period.

Their findings showed there was a correlation between pollution and photosynthesis: The lower the amount of aerosols, the higher the rates of photosynthesis.

Aerosols are fine particles in the air, such as dust or smoke. They can block sunlight from reaching plants, depriving them of their source of life.

Smoke from wildfires is a type of aerosol, but humans emit aerosols too, through transport and industrial activities, to name a few.

Satellite data showed that in 64 percent of Europe, plants were photosynthesizing more on the weekend, while human activity – and thus air pollution– was limited. Researchers added that they noticed a “weekly cycle.”

Another interesting finding concerned the infamous year 2020. As Covid-19 forced governments around the world to impose lockdowns, aerosol levels dropped dramatically, and photosynthesis occurred consistently throughout the week.

This alerted the researchers who, basing their calculations on 2020 aerosol pollution levels, established that plants could hold more than 41 million extra tons of CO2.

Such efforts would improve people’s health, benefit the ecosystem, and contribute to reducing greenhouse gas emissions which affect climate change.

This story originally appeared in the November 30, 2023 newsletter, Tragedy Redux.