Venice canal waters

Breathe, pause and reset

Image credit: Getty Images

As city streets become deserted and factories stand idle, air quality and wildlife are seeing immediate benefits, but what happens after lockdown is lifted?

The stay-in-place policies adopted by many governments around the world in response to the Covid-19 virus have reduced air and road traffic, two of the largest contributors to greenhouse gas emissions.

In Europe, reduced power use and manufacturing activity are estimated to have reduced emissions by 400 million metric tonnes, or 9 per cent of the year’s target emission levels.

For 15 years, Nasa has been measuring levels of NO2 – the gas emitted by vehicles, power and industrial plants – using data from its Ozone Monitoring Instrument on the Aura satellite. This year, levels were lower than 2019, due to environmental regulations China had introduced, but average amounts detected in 2020 in eastern and central China were 10 to 30 per cent lower than have been observed since 2005.

Asthma sufferers are expected to benefit immediately from reduced fine particulate matter measuring less than 2.5µm (PM2.5), which can irritate the respiratory tract, restricting breathing. These particulates can also enter the bloodstream via the lungs to cause other health problems.

Other events in recent history have also seen air quality improve. The UK introduced the 1956 Clean Air Act, which reduced smoke pollution. Its immediate results were the return of rare bird breeds such as hoopoes, bearded tits and house martins, and hawks were seen near London’s Piccadilly Circus.

Following the financial crash of 2008, there was a brief decline in emissions of about 1.4 per cent in 2009 but the recovery saw levels exceed pre-crash levels by over 5 per cent.

Professor Rob Jackson, chair of the Global Carbon Project, which works with his lab at Stanford University in California to measure greenhouse emissions, says: “Neither the fall of the Soviet Union nor the various oil or saving and loan crises of the past 50 years are likely to have affected emissions the way this crisis is.”

The National Centre for Atmospheric Studies (NCAS) has looked at air pollution in 10 cities: Birmingham, Belfast, Bristol, Cardiff, Glasgow, Leeds, London, Manchester, Newcastle and York. It found that NO2 and particulate levels are “significantly lower” than those normally seen at this time of year. The only exceptions were Belfast and York, where NO2 levels were slightly higher than usual. NCAS uses data from background air-monitoring stations, located away from main roads. Levels are compared with those of the same dates in the last five years to account for variations caused by weather patterns.

“The average level of particulate matter is lower in each city this year,” says Professor Alistair (Ally) Lewis, director of science at NCAS. “In the midst of a respiratory health crisis such as this, better air quality can only have a small effect, but it will undoubtedly be positive, relative to business-as-usual levels of pollution.”

A caveat is that air pollution can be affected by rain, which can dilute levels, so further analysis is required to establish the exact cause of these changes.

Sensors can gather air pollution data remotely but monitoring water quality and wildlife has been halted as researchers are confined to their homes. There is visible evidence of clearer waters, most notably in the canals of Venice in March, but this is due to reduced boat traffic, which has allowed sediment to settle, making the water clearer, which seems to be attracting fish and swans. The benefits from the reduced air pollution to rivers and animals will be quantifiable only after this period of isolation.

There are anecdotal reports of increased birdsong, says Anna Feeney, PR executive for the Royal Society for the Protection of Birds, but this may be due to reduced background noise. “If there is a boost in the number of breeding pairs next year, it will be difficult to say if it is climate-related,” she adds. Certainly, less traffic on the roads has led to less roadkill (foxes and hedgehogs) and fewer amphibians being killed as they migrate, but this also means that birds of prey will have less live creatures or carrion for food, she says.

Ground-nesting birds and those that nest on beaches may benefit as the nests will be walked past by fewer people and should not be disturbed.

The quieter roads are emboldening wildlife to venture into towns. A herd of wild Kashmiri goats came down from the Great Orme headland to wander around Llandudno in Wales, and deer and wild boar have been photographed roaming empty streets in Paris.


Find out where it’s app

Technology is helping individuals track the changes in their environment. The European Environment Agency (EEA) has developed the City Data Viewer, which tracks the weekly average concentrations of NO2, PM10 and PM2.5 (particulates measuring 10 and 2.5μm respectively). Weekly average concentration levels are calculated from daily mean values collected from over 3,000 air pollution measurement stations across Europe.

Some stand-out figures recorded so far are Barcelona, where the average concentration of NO2 for the week of 16-22 March 2020 was 55 per cent lower than for the same week in 2019, and London, where levels were 42 per cent lower.  

Earth Day has launched the Earth Challenge 2020 app, which it hopes will be the world’s largest citizen science environmental research project. “We want to help normalise citizen science and the process of participating,” says Anne Bowser, director of innovation at the Wilson Center think tank. “Everybody has social media, everybody is used to taking pictures, why not do it for scientific research?” she asks.

The global pandemic has curtailed the launch of the project on the 50th anniversary of Earth Day on 22 April. “We would have expected around 100 million data points to come out of Earth Day in a week or so,” says Kathleen Rogers, president of Earth Day. Instead there will be small-scale launches before a major launch in September.

“Unfortunately, the air quality getting better is going to be a blip,” Bowser concedes. “The opportunity here is to demonstrate that what humans do does make a difference on the environment.

The initial Challenge apps are for air quality and plastic pollution, with others to follow.

The closure of businesses means weekday power usage in Europe has declined. “Power demand is now significantly below the 2015-2019 range in many major European markets,” says Catherine Robinson, executive director at IHS Markit. “There are signs that demand is stabilising in those markets with lockdowns in place the longest. Across much of Europe, the weekday profile now resembles what you would see during a typical weekend,” she adds. The exception is Germany, which remained in its historical range, thought to be due to chemical industries still operating.  

The US, however, has reported an increase in residential power supply, as TVs, computers and power-hungry devices such as games consoles are used more than usual.

Renewable energy (solar, wind, tidal energy and hydroelectricity) could receive an impetus from a global lockdown. In the UK, renewable energy increased by 10 per cent compared with the March-April 2019 period, accounting for 43 per cent of generated electricity, while coal and gas reduced by 35 per cent and 24 per cent respectively. In Germany, renewables accounted for 60 per cent, up 12 per cent, compared with the same period in 2019.

Björn Ullbro, vice president for Europe and Africa at Wärtsilä Energy Business, comments: “The impact of the Covid-19 crisis on European energy systems is extraordinary. We are seeing levels of renewable electricity that some people believed would cause systems to collapse, yet they haven’t – in fact they are coping well.”

‘The impact of the Covid-19 crisis on European energy systems is extraordinary. We are seeing levels of renewable electricity that some people believed would cause systems to collapse, yet they haven’t – in fact they are coping well.’

Björn Ullbro, Wärtsilä Energy Business

The UK wind power industry, however, has been set back by production stoppages. Analyst GlobalData reports that installations for wind power could fall to 980MW in 2020, from 2.47GW in 2019, as companies stop production during the lockdown period. “Globally, the UK has become one of the most eminent players in the offshore wind market, with cumulative installed capacity growing from 1.34GW in 2010 to 9.97GW in 2019,” says Somik Das, senior power analyst at GlobalData. However, the Covid-19 pandemic could make it harder for wind farms to stay operational, he continued, as a shortage of engineering staff could extend repair times.  

The second half of this year would be critical for the industry, he says, depending on the rate of approval for projects and how quickly they can be carried out.

Wind turbine prices may increase by up to 10 per cent for the rest of the year in the UK, Das warns, as the quarantine measures may affect the movement of materials and staff, creating a supply bottleneck and lower production rates.

Wärtsilä reports that coal-based power generation fell by 29 per cent across the EU and UK between 10 March and 10 April in 2020 compared to the same period in 2019, and renewables increased by 8 per cent compared to 2019.  

Electric vehicle batteries may also be affected, as lithium mines are closed or have reduced production in response to the pandemic. Roskill, a consultancy serving the metal and mineral industries, estimates that approximately 110kt of lithium carbonate equivalent, the lithium compound, worth approximately $960m, could be lost this year.

Mining is one of the industries expected to ramp up quickly once restrictions are lifted. Roskill also reported that China’s metals and mining industries are showing signs of recovery, with economic activity beginning to return to pre-pandemic levels and consistent with a sharp recovery and full recovery by May or June, “assuming a second outbreak can be avoided”.

China’s oil and gas industry is also progressing with projects that had been delayed, according to GlobalData.  

It remains to be seen how permanent any of the benefits recorded thus far may be. More durable effects may be seen if people around the world have the collective will to maintain the behaviours that have resulted in better air quality and improved natural habitats. Will individuals reducing air travel, car journeys and reliance on fossil fuels be viable for countries whose economies have been devastated by the virus and the lockdown mechanism to prevent its spread?


A snapshot in time

Less air travel during the pandemic’s lockdown has reduced the levels of carbon dioixide (CO2) in the air. CO2 is classed as a greenhouse gas, which traps thermal energy, causing global temperature increases and affecting the Earth’s climate.

Mauna Loa CO2 measurement station is located on the slopes of the Mauna volcano in Hawaii and has measured atmospheric CO2 since 1958. In 2013, the centre recorded a daily mean concentration of CO2 in the atmosphere above 400 parts per million (ppm) for the first time. Although levels can be affected by weather conditions such as wind direction, there is a consistent increase of around 2ppm per year. In the 19th century, before the industrial revolution, global CO2 levels were 280ppm.

If measurements only began in 1958, how do we know the levels from hundreds, even millions of years ago? The answer is ice cores. From around the same time as Mauna Loa was established, researchers have been drilling deep into the ice in Greenland and Antarctica, extracting cores that contain air trapped in bubbles in the ice thousands of years ago. The air is extracted by a vacuum and analysed.

The ice cores show that levels of CO2 have gone up and down over millions of years. Variations occur as the Earth turns around the Sun but the last time CO2 levels were 400ppm was 300 million years ago, when early camels and horses were evolving but there were no humans. The Earth was also 3°C warmer than today.

Scientists are most worried about the rapid rate of change in CO2 levels. The Earth has been warmer, in the Eocene period (55 million years ago) and in the Jurassic period (183 million years ago) but these stages are all associated with major extinction events.


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