Damp outlook: Rainy days harm the economy

By Mark Waghorn via SWNS

Rainy days really do harm the economy, according to new research.

Productivity goes down when the number of wet days go up.

Rich countries are worst affected - with service and manufacturing sectors hit most.

The findings have implications for climate change due to more frequent weather extremes.

Lead author Dr. Leonie Wenz, of the Potsdam Institute for Climate Impact Research in Germany, said: "This is about prosperity, and ultimately about people's jobs.

"Economies across the world are slowed down by more wet days and extreme daily rainfall – an important insight that adds to our growing understanding of the true costs of climate change."

In July, record-breaking rainfall brought severe floods to Europe, where 200,000 properties lost electrical power.

In the same month, torrential rain with up to 202 mm in a single hour led to devastating floods in Henan province, China, uprooting more than one million people.

The catastrophic events each caused about £9 billion ($12.3 billion) in property damage.

"Macro-economic assessments of climate impacts have so far focused mostly on temperature and considered - if at all - changes in rainfall only across longer time scales such as years or months, thus missing the complete picture,"Dr. Wenz said.

"While more annual rainfall is generally good for economies, especially agriculturally dependent ones, the question is also how the rain is distributed across the days of the year.

"Intensified daily rainfall turns out to be bad, especially for wealthy, industrialized countries like the US, Japan or Germany."

The UK is now seven percent wetter than it was when the study began. In recent years, we've seen the devastation flooding has caused.

Whole communities have been left struggling to cope. Between November 2019 and February 2020, severe winter flooding occurred across the country.

Last summer, London was hit by a series of flash floods that left homes and businesses underwater.

The west coast of Scotland is one of the rainiest places on the continent - with places that receive over 3,000 mm per year.

In some years rainfall can even reach about 6,000 mm - unseen in other parts of Europe.

The international team analysed sub-national economic output for 1,554 regions across 77 countries from 1979 to 2019.

They combined the data from agricultural, industrial and services sectors with high-resolution records of global daily precipitation over the past 40 years.

By using detailed statistics beyond simple averages the researchers found rain has the most profound financial effect.

It suggests intensified deluges driven by global warming from burning oil and coal will harm the global economy.

Droughts that differ from historical monthly averages may also lead to economic losses.

First author Maximilian Kotz, a PhD student at Potsdam, said: "We identify a number of distinct effects on economic production, yet the most important one really is from extreme daily rainfall.

"This is because rainfall extremes are where we can already see the influence of climate change most clearly, and because they are intensifying almost everywhere across the world."

Alterations in the Earth's hydrological cycle are anticipated as a result of manmade climate change.

Water availability affects agricultural productivity, labour outcomes and conflict. Flash flooding can cause damage and impact economic output.

Rainfall predictions are hard to model - or assessed on a single country basis. It is difficult to estimate the global economic cost.

By loading the Earth's atmosphere with greenhouse gases from traffic and industry, humanity is heating the planet.

Warming air holds more water vapor - that eventually becomes rain. The effect explains the increasing number of floods.

Atmospheric dynamics make regional changes in annual rainfall average complicated but daily rainfall extremes are increasing globally due to the 'water vapour effect.'

Co-author Professor Anders Levermann, also from Potsdam, said: "Our study reveals it's precisely the fingerprint of global warming in daily rainfall which have hefty economic effects that have not yet been accounted for but are highly relevant.

"Taking a closer look at short time scales instead of annual averages helps to understand what's going on.

"It's the daily rainfall which poses the threat. It's rather the climate shocks from weather extremes that threaten our way of life than the gradual changes.

"By destabilizing our climate we harm our economies. We have to make sure our burning of fossil fuels does not destabilize our societies, too.”

The study was published in the journal Nature.