The sky really IS a deeper shade of blue: Reduced pollution levels during lockdown are making UK skies look like we’re on a tropical island, scientists say
- Drastic falls in traffic, and the resultant levels of pollution, have given the heavens a rich hue that can usually only be found somewhere more exotic
- Climate professor William Collins said the sky is naturally a deep blue but pollution adds a haze that makes it look paler as the fine particles absorb light
- Another short-term benefit is that deep blue skies have a positive psychological effect, even if we are stuck indoors as the clear skies put us in a better mood
It might seem like a cruel trick of the mind for those trapped indoors during lockdown – but Britain’s skies really have turned a deeper shade of blue.
Drastic falls in traffic, and the resultant levels of pollution, have given the heavens a rich hue that scientists say is usually found only on remote tropical islands.
Fine particles from vehicle emissions dull the light we normally see, even on a sunny day. But with far fewer cars choking the roads and just a fraction of the normal number of jets in the air, the sky is more vivid.
William Collins, a climate professor at the University of Reading, said the sky is naturally a deep blue but pollution adds a haze that makes it look paler as the fine particles absorb light.
People practicing social distancing at Tynemouth beach as the UK continues in lockdown to help curb the spread of the coronavirus
‘The absence of traffic will be having an effect,’ he said, adding that there was ‘no question’ the current skies were ‘the kind of blue you’d expect to see on a nice tropical island somewhere. Everybody’s been noticing it’.
The effect of reduced pollution is even more dramatic when the wind is coming from the east, as it is at present.
‘At the moment, the wind direction is coming over the Channel from the Continent which we would normally expect to be very polluted, and which would also make our skies hazier,’ Prof Collins added.
Not all the effects of reduced traffic are so visible, but levels of nitrogen dioxide – which is linked to lung problems and reduced life expectancy, as well as acid rain – are also plummeting.
Professor James Lee, an expert in atmospheric chemistry at the University of York, said: ‘Since the lockdown there has been quite a large drop in nitrogen dioxide pretty much uniformly in every city that we’ve looked at by 30 to 40 per cent.’
But he cautioned that the ‘relatively short period of relief’ would probably not be enough to make a difference to public health in the longer term. ‘What it does show is what can be achieved,’ he said.
Blue skies over a London park as the lack of pollution makes the sky a more vivid blue
‘We’re looking at this as a little bit of a window into the future when, say, in ten, 15, 20 years from now, where a lot of the vehicle fleet is likely to be electric, this is what the air is going to be like in our cities.
‘Secondly, people may realise once the restrictions have been lifted that maybe we don’t need to travel as much, don’t need to work in the office as much, and that has an immediate effect on the air and our wellbeing.
‘I hate to say it’s an exciting time to be an atmospheric scientist, but it kind of is. We would never have expected to be able to have something like this.
‘It’s an awful thing that’s happening but if there is one slight silver lining, it’s that the air in the cities is much cleaner.’
Another short-term benefit is that deep blue skies have a positive psychological effect, even if we are stuck indoors.
‘I may be sitting in a study surrounded by computer screens,’ says Prof Collins.
‘But I can look out of the window and see a nice blue sky – so that does make being shut away slightly more bearable.’
People are pictured making the most of the greenery at Binfield Health in Oxfordshire this week