Interested in this kind of news? Receive them directly in your inbox. Delivered once a week. Sign Up In terms of air pollution, the levels recorded in Lisbon showed air quality at its best since 1994 – and possibly earlier than that, because air quality monitoring only began in Portugal in 1994. The average annual limit value for NO2 in the capital city is 40 micrograms per cubic metre. Last year, the monitoring station registering the worst levels in Lisbon (in Liberty Avenue) recorded 55 µg/m3, yet during lockdown this was down to 20µg/m3. CO2 emissions were also down, thanks to a reduction in electricity consumption of 13%. Emissions for the three months March-May fell by 1.4 million tonnes compared with the same period in 2019. Although the state does not measure noise levels, Zero has been measuring noise for years. We measured noise over a 48-hour period near Lisbon airport and found that, for the first time, the city was compliant with its required limit values (thanks to a combination of less road and air traffic). Compared with measurements taken last July, noise levels were 11 decibels lower during lockdown. We had people saying they could hear the birds, and they could finally enjoy Lisbon’s parks for the areas of nature they are intended to be. Such gains were never going to be sustained when the restrictions began to be eased, and by the second half of May the Liberty Avenue NO2 measurements were back up to 38µg/m3. But we have reason to hope that some of the benefits will be maintained. Since public health is such an important issue, the fact that air pollution came down so drastically when car traffic largely disappeared has made the case that we have to change mobility patterns. The problem is that public transport isn’t really a solution. Lisbon’s public transport was already collapsing under the weight of its own success, largely because government incentives for individuals and families to use trains and buses had led to a demand that could not be met before social distancing was necessary and it is even harder now. The city authorities in Lisbon are investing in cycling. Lisbon is the current European Green Capital, so it has to set some kind of example, and it has a support package for cycling, including help for people buying bikes, cycle lanes, and cycle sharing schemes. In addition, the Portuguese government is offering a subsidy of 10% of the price up to €100 for people buying bikes but the municipality will support 50%, up to €350 . Another gain from the lockdown period should come in the number of people working from home. It has been agreed that 25% of people working in public administration will work from home, and many companies have realised that it costs them less to have workers at home rather than in the office. The biggest obstacle to keeping the gains from the coronavirus period appears not to come from any lobby arguing against cleaner air or more home working, but from a lack of proactivity on the part of the national and city authorities. That is why Zero has used the numbers from our monitoring of noise, air pollution and CO2 emissions to put pressure on municipalities to develop measures to prevent concentrations going back to the old normal. We have seen that drastic reductions are possible – we just have to make them permanent.