As coronavirus spreads and impacts work and travel worldwide, reduction in carbon monoxide mainly from cars had been reduced by nearly 50% compared with last year and helped levels of air pollutants, CO2 and other warming gases fall rapidly over some cities and regions, researchers in New York told the BBC as their early results showed.
Emissions of the CO2 gas that cause heating of the planet have also fallen sharply.
However, after the pandemic, emission levels could rise rapidly as per the warnings.
As the coronavirus pandemic is ramping down the economic activity globally, it is hardly surprising that energy and transport-related emissions of a variety of gases would be reduced.
Scientists say that when CO2 emissions are at their peak by May, the levels recorded might be the lowest since the financial crisis over a decade ago due to the decomposition of leaves.
According to the data collected in New York this week, the instructions to curb unnecessary travel are having a significant impact.
Researchers at Columbia University say traffic levels in the city were estimated to be 35% down than a year ago. Emissions of carbon monoxide, mainly from cars and trucks, have fallen by around 50% for a couple of days this week.
There was a 5-10% drop in CO2 over New York and a major drop in methane as well, they have also found.
“New York has had exceptionally high carbon monoxide numbers for the last year and a half,” said Prof Róisín Commane, from Columbia University, who carried out the New York air monitoring work.
“And this is the cleanest I have ever seen it. It’s less than half of what we normally see in March.”
These findings echo the environmental impacts connected to the virus outbreaks in China and in Italy, although there are a number of caveats.
An analysis carried out for the climate website Carbon Brief by the experts suggested that over a two week period, there had been a 25% drop in the use of energy and emissions in China. They believe that it is likely to lead to an overall fall of about 1% in China’s carbon emissions this year.
Significant falls in nitrogen dioxide related to reduced car journeys and industrial activity have been recorded both in China and Northern Italy. The gas is not only a serious air pollutant but also a powerful warming chemical.
Across many countries as millions of people working from their home and aviation grinding to a halt, a range of emissions are likely following the same downward path.
However, as people are working from home, it will likely increase the use of home heating and electricity, but the curbing of commuting and the general slowdown in economies will possibly affect overall emissions.
“I expect we will have the smallest increase in May to May peak CO2 that we’ve had in the northern hemisphere since 2009, or even before,” said Prof Commane.
People who believe that the shutdown will impact CO2 levels for the whole of this year echoed this view.
“It will depend on how long the pandemic lasts, and how widespread the slowdown is in the economy particularly in the US. But most likely I think we will see something in the global emissions this year,” said Prof Corinne Le Quéré from the University of East Anglia.
“If it lasts another three of four months, certainly we could see some reduction.”
The way the governments decide to re-stimulate their economies once the pandemic eases, likely to make a significant difference to the scale of carbon emissions and air pollution.
After the global financial crash in 2008-09, carbon emissions shot up by 5% because of stimulus spending that boosted the use of fossil fuel.
However, governments will have a chance in the coming months to alter that result. For e.g., they could insist that far more stringent reductions in aviation emissions would be tied to any bailout of airlines.
“Governments now have to be really cautious on how they re-stimulate their economies, mindful of not locking in fossil fuels again,” said Prof Le Quéré.
“They should focus those things that are ready to go that would lower emissions, like renovating buildings, putting in heat pumps and electric chargers. These are not complicated and can be done straight away, they are just waiting for financial incentives.”
However, some argue that if the pandemic continues for a long time, any stimulus would more likely focus on promoting any economic growth regardless of the impact on the environment.
“I certainly think climate could go on the back burner, and in this case, I don’t think there is much hope that stimulus goes to clean energy,” said Prof Glen Peters from the Centre for International Climate Research.
“Any stimulus will help those with job losses such as tourism and services. I think this is very different to the global financial crisis. The only silver linings could be to learning new practices to work remotely, and buying a few years of lower growth allowing solar and wind to catch up a bit, though, these may be rather small silver linings.”
