GEORGE TOWN: The sea looked cleaner and the sky looked brighter when almost the whole world recently went into a lockdown caused by the Covid-19 pandemic. But did the environment really get better?
Not much, according to scientists, but they were still delighted with some of the results.
Atmospheric physicist Dr Yusri Yusup said by mid-January, as China and many other countries began their lockdown, there was a dip in the amount of carbon dioxide (CO2) in the air.
It was lower than in 2018 but still higher than in 2019.
“Malaysia has little impact on CO2 in the air. We produce just 1% of the world’s electricity, but China produces 25%.
“When China went into lockdown, the world’s CO2 level dropped, ” he said.
But only by about five parts per million (ppm) compared with 2018.
Yusri is from Universiti Sains Malaysia and measures parameters in the air from a station in Teluk Bahang.
He said the amount of CO2 in the air dropped from almost 420ppm in early November to about 410ppm by end February.
But in mid-February last year, the CO2 level was lower at about 405ppm.
When China began reopening its economy from late February this year, the amount of CO2 in the air shot steadily up again and reached 430ppm by early May.
“Malaysia’s movement control order (MCO) that began on March 18 has no effect on the CO2 level at all, ” he said.
He stressed that CO2 was a greenhouse gas and not an air pollutant.
Locally, there were big improvements in Malaysia’s air quality, but CO2 readings from Teluk Bahang showed that climate change and global warming hardly slowed even though many industries in the world were closed to deal with the virus.
“It might take five years for CO2 levels to drop after fossil fuel stop burning. The world needs time to absorb all the CO2 we produce.
“The pandemic gave scientists a chance to see what might happen to the environment when human activity slows down on a global scale.
“We can see now what may happen if we drastically cut back on fossil fuel burning.
“We see it might not be worth the effort because we can sacrifice much of the global economy but for little improvement, ” he said, adding that he was conducting a deeper study into the data.
For now, however, Yusri said the cyclic of up and down of CO2 levels followed the same pattern as previous years, pandemic or not.
He said other researchers had found that Malaysia’s air quality improved by as much as 58% during the MCO, “but this is temporary. As soon as the economy reopens fully, the air quality will drop again”.
At sea, marine biologist Prof Datuk Dr Aileen Tan said there was also hardly any change.
“The sea may look cleaner but when we deep-dive into the facts and figures, we found little difference, ” she said.
She said USM’s Centre for Marine and Coastal Studies continued to receive reports of farmed fish in cages dying by the tonnes due to lower dissolved oxygen caused by severe algal blooms at sea.
However, Prof Tan did find one pleasant difference: the sea around Penang has become less acidic during the MCO.
“Much of the acidity is caused by dissolved CO2, which will form acidic bicarbonate compounds in seawater, ” she said.
She said the pH of the sea rose by 0.15 during the MCO (a higher pH means a more alkali state).
“This has a profound effect on shellfish larvae like shrimps and molluscs.
“Being microscopic, even that little drop in acidity will make it easier for them to absorb carbonates and form their shells, ” she said.