How much could be heated Bucharest to 2100 – in the most pessimistic scenario we could have dozens of summer days
Landscape from Bucharest (photo Calinescu Silviu, Dreamstime.com)
Bucharest becomes warmer, there are more and more hot days and more and more tropical nights. The heating will continue, meteorologists have four scenarios, and in the most pessimistic, at the end of the century it would be three months in which the air temperature can exceed 30 C, an article infoclim.ro, signed by two ANM researchers, shows.
A capital that will suffer much because of climate change
Bucharest is among the most exposed European capitals to the effects of climatic changes, especially to the heat waves. According to a report by the World Bank Group (2023), the capital of Romania is on the 3rd place in Europe at the risk of mortality associated with extreme temperatures, after Istanbul and Athens.
The surfaces covered with concrete, bitumen, asphalt or other similar materials change the temperature by a few degrees, in proportion to the size of the surface. Thus, the cities of the size of Bucharest (several hundred ha) can change the ambient temperature, becoming warmer by 5-6 ⁰C than the surrounding region, thus generating the phenomenon called “urban heat island”, explained in the article.
Meteorologists are based on four scenarios to estimate how the climate will evolve until 2100, starting from a moderate one, to a severe one. In which we will fit, it depends a lot depending on the measures we will take (the growth of the green surfaces in the cities, the use of less absorbent heat for infrastructure, the thermal rehabilitation of the buildings).
The most severe scenario indicates a prolonged summer
Tropical days, ie those in which the air temperature exceeds 30 ° C, are increasingly frequent in the capital, and the tendency is growing and more accelerated in the following decades. In the most pessimistic scenario, the one with high emissions, the annual number of tropical days could exceed 100 until the end of the century.
Basically, we could have another three months in which the air temperature exceeds 30 ° C. In contrast, the moderate scenario that involves emission reduction policies, shows a slower but still significant growth.
Basically, every two years we have an extra tropical day in the most severe scenario. Tropical nights, those in which the air temperature remains at values higher than 20 ° C, tend to be more frequent. If at the beginning of the twentieth century such nights were generally rare, after 2000 there are over 20 tropical nights each year.
The difference between the number of tropical nights from the Bucharest-Filit weather stations (located in the city center) and Bucharest-Filret (located on the northern periphery) highlights the influence of the city on the air temperature (the effect of urban heat).
Starting with 2050, the maximum average temperature of July could frequently exceed 32 ° C in the darkest scenario. In the more optimistic version (with successful mitigation measures), the growth is slower, reaching 32 ° C especially towards the end of the century.
The research also shows that during the summer, the population that lives on more than 50% of the capital's surface is subject to a high and very high risk of extreme temperatures and heat waves, which coincides with the surface of the anthropic city. Basically, only the areas near the parks and lakes, but also the areas with 1-2 floors and gardens are less affected by the thermal risk.
The article is signed by Sorin Cheval (geographer specialized in climatology) and by Vlăduț Fălcescu (meteorologist within the Climatology Directorate of the National Meteorological Administration).
Photo source: dreamstime.com
