Newswise – Warming during Europe’s summer months has been much faster than the global average, shows a new study conducted by researchers at Stockholm University and published in Amwaa Journal of Geophysical Research. As a result of human emissions of greenhouse gases, the climate across the continent has also become drier, particularly in southern Europe, leading to worse heat waves and increased fire risks.
According to the United Nations’ Intergovernmental Panel on Climate Change (IPCC), warming over land areas is happening much faster than over oceans, at 1.6 degrees and 0.9 degrees, respectively. This means that the global budget for greenhouse gas emissions to stay below 1.5 degrees of global warming has already been exhausted. Now, the new study shows that the emissions budget was also used to avoid a two-degree temperature rise over large parts of Europe during the summer half year (April-September). In fact, measurements reveal that warming during the summer months in large parts of Europe over the past four decades has already exceeded 2 degrees.
“Climate change is dangerous because it leads, among other things, to more frequent heat waves in Europe. These, in turn, increase the risk of fires, such as the devastating fires in southern Europe in the summer of 2022,” says Paul Glantz, associate professor at Stockholm University Department of Environmental Sciences, and lead author of the study.
In southern Europe, the so-called warming-induced positive feedback is clearly visible, that is, warming is amplified by soil drying and reduced evapotranspiration. Furthermore, there was less cloud coverage over large parts of Europe, possibly as a result of less water vapor in the air.
“What we’re seeing in southern Europe is consistent with what the Intergovernmental Panel on Climate Change has predicted, which is that increasing human impact on the greenhouse effect will lead to drier regions on Earth,” says Paul Glantz.
The effect of aerosol particles
The study also includes a section on the estimated effect of aerosol particles on temperature increase. According to Paul Glantz, rapid global warming, for example, in Central and Eastern Europe, is primarily a consequence of anthropogenic emissions of long-lived greenhouse gases, such as carbon dioxide. But since emissions of short-lived aerosol particles from, say, coal-fired power plants have fallen dramatically over the past four decades, the combined effect has led to a severe temperature increase of more than 2 degrees.
“Aerosol particles, before they began to decline in the early 1980s in Europe, masked human-caused greenhouse gas warming of just over 1 degree on average in the summer half of the year. As aerosols in the atmosphere decreased, so did the degree Heat quickly. Human carbon dioxide emissions remain the biggest threat because they affect the climate for hundreds to thousands of years,” says Paul Glantz.
According to Paul Glantz, this effect provides a harbinger of future warming in regions where aerosol emissions are high, such as India and China.
Key Facts – The greenhouse effect and the aerosol effect
Burning fossils releases aerosol particles and greenhouse gases. Although their source is common, their impact on climate varies.
about the greenhouse effect
Greenhouse gases are largely unaffected by solar radiation while efficiently absorbing infrared radiation, resulting in re-emission towards Earth’s surface. The Earth absorbs both solar and infrared radiation, warming the lower part of the atmosphere in particular.
Timescale: Greenhouse gases are generally long-lived in the atmosphere. This applies above all to carbon dioxide, where human emissions affect the climate for hundreds to thousands of years. It also means that greenhouse gases are spread evenly across the planet.
About the effect of aerosols
Unlike greenhouse gases, aerosol particles affect the incoming solar radiation, that is, they scatter part of the sunlight back into space which leads to a cooling effect. Human emissions of aerosols can enhance this cooling effect.
Time and space: Airborne human aerosol particles are about a week old, which means they mainly cool the climate locally or regionally and in the short term.
According to the Paris Agreement, all parties must commit to significantly reducing greenhouse gas emissions, but it is also important to reduce the concentrations of aerosol particles as well because, in addition to their impact on the climate, aerosol particles in polluted air cause nearly eight million. premature deaths every year around the world.