A new study tracking 25 European countries from 2017 to 2023 documents a problematic reality: when droughts strike, hydropower and other renewables don’t work as well as they might.

As a result, countries have to fire up more fossil fuel power plants and import energy to keep the lights on.

Europe risks a vicious cycle where conditions made worse by carbon emissions force countries to emit even more carbon.

In this case, researchers found power production in the EU from fossil fuels increased over the seven-year-period by 180 TWh, which is the equivalent of 7 per cent of the EU’s total generation in 2022, according to a 2023 European Electricity Review.

So as climate change makes dry spells more frequent and severe, Europe risks a vicious cycle where conditions made worse by carbon emissions force countries to emit even more carbon.

Here’s the size of the problem: Fossil fuel plants used to fill the energy gap during the seven drier-than-average years the researchers studied emitted an extra 141 million tonnes of CO₂ equivalents. That’s more than the total annual emissions from fossil fuel combustion in the Netherlands

There’s the goal of reducing imports of fossil fuels from these geopolitical areas for energy security. So there are a lot of positive advantages to the growth in renewables in Europe.

“It’s true that today we are still dependent on fossil fuels to compensate for shortages in renewable energy, but there are solutions that can help us get rid of this dependency,” said Francesco Cherubini, the senior author of the paper and head of the Norwegian University of Science and technology (NTNU’s) Industrial Ecology Programme.

“We are on track to move away from this problem, but we still need changes in our electricity systems and networks,” he said.

Drought doesn’t just cause Europe’s CO₂ emissions to skyrocket. Burning fossil fuels also releases air pollutants that have a direct effect on people’s health.

This is an effect of climate change that people experience directly.This is something that impacts your pocket, because of electricity bills and electricity supplies.

Here, the researchers looked at three common pollutants released by burning fossil fuels: sulphur dioxide, nitrogen oxides and very fine inhalable particles, called PM2.5.

None of these are good for us or the environment. Sulphur dioxide causes acid rain. Oxides of nitrogen irritate your lungs and cause smog.

PM2.5 particles are so small that when you inhale them, they actually enter your bloodstream. That can affect your heart and lungs, according to the US Environmental Protection Agency.

In this case, PM2.5 emissions represented roughly 4 per cent of the total amount of air pollutants. But the researchers found that the particles were responsible for 20 per cent of the harms the pollutants caused for human health.

By mapping each country's energy mix, the researchers could pinpoint which countries suffered most from excess pollution when fossil fuels were used to fill the electricity gap.

Natural gas was the most commonly used fossil fuels in this situation. Power production from coal and its dirtier cousin, lignite was just one-fifth of that from natural gas.

But pollution from coal and lignite plants was 10 times higher for PM2.5 and 130 times higher for sulphur dioxide compared to pollutants from burning natural gas.

When it came to PM2.5 emissions, Bulgaria, Spain, and Italy topped the charts. That’s because they’re in a sweet spot where emissions from lignite plants in eastern Europe and from coal plants in western Europe converge.

France was the opposite: droughts actually cut the country’s use of coal, for a variety of reasons. That meant negative PM2.5 emissions during dry spells.

The social and environmental cost of this drought-related use of fossil fuel plants was an estimated $26 billion.

It may seem counterintuitive, but Cherubini says one of the best solutions now is for countries to continue to invest in renewable energy and expand cross-border power interconnections.

Societies need to stop adding more CO₂ to the atmosphere, he says, because that will absolutely make the problem worse over time.

There are other benefits.

“This will also reduce air pollution,” he said. “Renewables are also getting cheaper, and are cheaper than investing in fossil fuel fired plants.”

Another incentive is being made evident by the war in the Middle East is energy security.

“There’s the goal of reducing imports of fossil fuels from these geopolitical areas for energy security,” he said. “So there are a lot of positive advantages to the growth in renewables in Europe.”

European countries are already beginning to adopt some of the approaches that can help cut demand when supply is short.

One is voluntary power cuts when demand is high. This is when factories, commercial buildings or even smart home devices are set up to throttle back their energy use for short periods when peak demand is high.

For example, Norwegian electric car owners can get small discounts if they allow their charging schedule to be synched with times of lower power demand.

Another concerns better connections between countries. There are now links between Norway, Germany and the UK via the NordLink and North Sea Link cables. Those allow surplus power to move from regions that have it to those that don’t.

Some solutions aren’t quite ready for full rollout yet.

Boosting battery storage and developing clean hydrogen are two examples that could to soak up surplus renewable electricity when it's abundant and releasing it when hydropower falls short, Cherubini said.

A warmer planet will mean more, and more severe, droughts. Xianping Hu, a researcher in NTNU’s Industrial Ecology Programme and the lead author of the article, says their findings should be a wakeup call for Europe.

“We need to be prepared when something extreme happens,” he said. “We have to build our systems to be more resilient.”

Global warming can seem abstract, Cherubini added, but when severe droughts affect power prices, it makes this problem concrete.

“This is an effect of climate change that people experience directly,” he said. “We’re not talking about melting glaciers in the north, or flooding in the tropics. This is something that impacts your pocket, because of electricity bills and electricity supplies.”