Is Spain's wetter weather caused by less pollution? Met office responds

 

IT FEELS as though it's been raining almost non-stop since the lockdown began – or at least 50% of the time, with much of the other 50% bringing ominous-looking clouds. But this is not as grim as it sounds; abundant spring and autumn rain means plenty of plump, tasty fruit and vegetables, well-topped up reservoirs, and consequently, paying less for greengroceries and for water bills in summer – and in Spain, constant hot weather and sunshine are guaranteed for a minimum of three months of the year anyway, after about eight weeks from now.

Yet long-term residents find the constant rain unusual: Much of the centre of the country is bone-dry for the majority of the year, and the Mediterranean experiences torrential downpours in spring and autumn for about four days at a time and then nothing for weeks, and the last time the latter heard a continual patter of drops on the roof and windows for the best part of a couple of months, especially in early spring, was around 15 years ago.

In fact, until about two years ago, most of Spain was gripped in a very worrying drought which even led to water consumption being restricted in the hottest, driest and most densely-populated areas for parts of the day – but this situation seems to be consigned to history.

What's different about this year?

Clearly, 2020 is unusual insofar as the presence of humans, traffic and industry has reduced to almost nil outside, and air pollution in built-up areas has plummeted as a result – in Madrid, where local and regional governments have long been battling to keep this in check, it has fallen by 11% since mid-March and, for the first time in years, if not decades, the Madrid skyline is starkly visible day and night from the town of Alcalá de Henares – 37 kilometres to the east.

And nitrogen dioxide levels have plunged in Spain's main cities by 64% on average – in fact, exactly 64% in Valencia, and even more so in the country's largest two metropolitan areas, Madrid (73%) and Barcelona (83%).

This is not only the case in Spain – residents in the Indian capital of Delhi have reported being able to see the Himalayas from their windows for the first time in over 30 years.

One would assume that the plunging levels of air pollution would be helping to make way for clouds to form, and therefore increasing rainfall in terms of volume and frequency – and Spanish reporters have asked the State meteorological agency, AEMET, if the two are linked.

Its director, José Antonio Maldonado, says rainfall in March this year was 95% above average, making it the fourth-wettest March so far this century and the seventh since 1965 when records began.

According to AEMET's data, several provinces and provincial capitals broke all known records for rain volume within a 24-hour period – Badajoz (Extremadura), Castellón, Murcia, Teruel (Aragón), and in La Rioja's main city, Logroño.

April last year was much wetter than average, Maldonado explains, but – although April 2020 is not yet over – the amount of rain so far this month shows that by the time it finishes this coming Thursday, it will have been considerably soggier than April 2019.

“By the middle of the month, we'd already pretty much exceeded the average April rainfall, and it has continued raining after then – at times, too much, especially in the Mediterranean area and particularly in Catalunya and the Balearic Islands,” reveals Maldonado.

Whilst, officially, a northern-hemisphere spring outside of the tropics runs from March 21 to June 21 – from the spring Equinox to the summer solstice – the meteorological spring covers the whole of March, April and May, with the meteorological summer starting on June 1, according to Maldonado.

These three months were very wet in 2018, more so than they would be in 2019, and yet the same period in 2020 looks set to beat both years.

But does this have anything to do with reduced air pollution?

“No, there's no connection. Last April was very rainy, although March and May were not, and we were all in full operation then,” Maldonado counters.

“That said, the reduction in air pollution means there's less acid rain.”

A term first coined in the 1980s, and which sparked public horror – with everyone's first thought being that it would actually be raining corrosive battery chemicals on their heads – 'acid rain' is merely when the pH level is on the left-hand side of neutral, or over 6.6, and creeping slightly further towards the yellow than the blue.

A lower pH reading in the rainwater means, naturally, a lower pH level in the seas, and this slight imbalance is enough to affect subaquatic flora and fauna, changing reproduction cycles, reducing the levels of certain marine plants, and therefore creating a longer-term impact on the underwater ecosystem.

Surely, then, this means the sudden and near-total halt to polluting human-generated activity will help slow down climate change?

“It's a bit like throwing a glass of water into the high seas,” Maldonado responds, putting a damper on the widespread global optimism.

“This sudden halt is not going to be enough. Climate change is a long-term process and, as soon as we're back up and running again at normal levels, greenhouse gases will, once again, be floating around the atmosphere as they were before.

“A few weeks of very low pollution are not going to have enough of an impact on the evolution of our planet's climate.”

But it's a good place to start, and perhaps the unprecedented slump in smog and murky waters worldwide will spur on authorities and industries to find ways of keeping the planet's air quality as close to that of lockdown time as they can, even once everyone goes back to work and to commuting.