Heatwaves are not as visible as floods and earthquakes, but they can be just as deadly. A recent study estimated that a ten-day spell of extreme heat starting on June 23rd killed around 2,300 people in 12 European cities. The researchers say that climate change made the heatwave between 1°C and 4°C hotter, enough to explain two-thirds of the deaths. High temperatures cause heat stroke, strain the heart and worsen chronic illnesses such as diabetes. More red alerts were issued across Europe on August 10th.
Europe is both warming faster than most parts of the world and, compared with other rich regions, appears to be ill-equipped to cope. Since the mid-1990s average temperatures on the continent have risen by 0.53℃ per decade, more than double the global land average of 0.26℃. Changing weather patterns have created more frequent and intense heatwaves. Europe’s efforts to cut air pollution over the past few decades have also raised temperatures, as some pollutants reflect sunlight back into space. And the fact that some of Europe is in the Arctic matters, too. The Arctic is the fastest-warming region on Earth; as ice melts it reflects less sunlight, speeding up the process.
But European cities appear to suffer more than cities in other rich regions even when peak temperatures are similar. Data from Kai Chen, of the Yale School of Public Health, and his colleagues shows that, when comparing cities with similar climates, the increase in mortality on days with temperatures in the 99th percentile for that location is far higher in Europe than in Asia or the Americas. For example, Turin, in northern Italy, and Toronto, Canada’s biggest city, have similar temperatures on their hottest days. But the risk of death on these days rises by more than 50% in Turin compared with 14% in Toronto.
Europe’s lack of air conditioning is surely part of the problem. The share of homes with air con in Britain, the Netherlands and Italy is still estimated to be only 5%, 20% and 49%, respectively. In America and Japan the figure is 91%. In countries that have increased their use of air con, deaths have come down. In Spain the share of homes with air con rose from 5% in 1991 to more than 40% today. Over the same period the risk of death from heat on hot days fell by 30-60%.
European cities, % increase in risk of death on days with 99th percentile temperature
By region
Northern
Western
Eastern
Southern
Hotter places tend to have a greater mortality risk when temperatures rise. But Pierre Masselot and his colleagues at the London School of Hygiene and Tropical Medicine found that Europe’s cities vary widely in their vulnerability to heat. Accounting for differences in local temperatures, the riskiest cities tend to be some of the continent’s most built-up urban areas. Dark surfaces made of concrete and tarmac absorb and retain heat, which makes big cities, especially those with few green spaces, hotter than more rural areas (this is not always captured in air-temperature data that are based on modelling). Other building materials also play a role: the iconic grey zinc roofs in Paris bake the flats beneath them. The relative risk of death in Paris rises by 56% on 99th-percentile days, far more than in places with similar temperatures.
Italian cities fare particularly poorly: Bologna tops the risk table and among large cities Milan is worst. Why it suffers more than Rome, which endures similar heat, is unclear. One reason may be that Milan is one of the most polluted cities in Italy: although pollutants can cool a region, high levels of particulates also worsen heat’s effects on health. Italy’s ageing population may add to the risk—40% of heat-related deaths occur in people aged over 85.
European cities, % increase in risk of death, by temperature
By region
Northern
Western
Eastern
Southern
The researchers also found that Amsterdam and London are far deadlier in hot weather than other European cities with similar temperatures. In both London and Copenhagen, for example, the 99th-percentile daily average is about 22°C (although daily maximums are several degrees higher). In London that raises the death risk by 45%, in Copenhagen by 14%. On average, a 22°C day in London is as deadly as 28°C across other European cities. Places with more poverty also suffer more during heatwaves. Poorer areas tend to have less green space, worse housing and residents who are more vulnerable. An analysis by Carbon Brief, a climate-news website, found that people in the most deprived neighbourhoods in English cities were three times more likely to experience extreme heat than those in the least deprived ones.
Scorching summers might also mean warmer winters. That could bring down deaths related to cold weather, which in Europe outnumber those from heat. A separate study by Dr Massalot found that many cooler cities may see a reduction in the overall death rate from extreme temperatures over the next 25 years. But, if no changes are made, already hot cities in Europe will see big increases in excess deaths related to heat. Florence is among the places that are forecast to suffer the most: by 2050 its death rate from heat may triple compared with the level in 2010, to 105 deaths per 100,000 people. Even cooler cities will feel the heat. Dublin’s heat-related mortality rate could increase more than ten-fold, albeit from a much lower base. To save lives, Europe needs to find ways to keep cool over the summer.■
Heatwaves are not as visible as floods and earthquakes, but they can be just as deadly. A recent study estimated that a ten-day spell of extreme heat starting on June 23rd killed around 2,300 people in 12 European cities. The researchers say that climate change made the heatwave between 1°C and 4°C hotter, enough to explain two-thirds of the deaths. High temperatures cause heat stroke, strain the heart and worsen chronic illnesses such as diabetes. More red alerts were issued across Europe on August 10th.
Europe is both warming faster than most parts of the world and, compared with other rich regions, appears to be ill-equipped to cope. Since the mid-1990s average temperatures on the continent have risen by 0.53℃ per decade, more than double the global land average of 0.26℃. Changing weather patterns have created more frequent and intense heatwaves. Europe’s efforts to cut air pollution over the past few decades have also raised temperatures, as some pollutants reflect sunlight back into space. And the fact that some of Europe is in the Arctic matters, too. The Arctic is the fastest-warming region on Earth; as ice melts it reflects less sunlight, speeding up the process.
But European cities appear to suffer more than cities in other rich regions even when peak temperatures are similar. Data from Kai Chen, of the Yale School of Public Health, and his colleagues shows that, when comparing cities with similar climates, the increase in mortality on days with temperatures in the 99th percentile for that location is far higher in Europe than in Asia or the Americas. For example, Turin, in northern Italy, and Toronto, Canada’s biggest city, have similar temperatures on their hottest days. But the risk of death on these days rises by more than 50% in Turin compared with 14% in Toronto.
Europe’s lack of air conditioning is surely part of the problem. The share of homes with air con in Britain, the Netherlands and Italy is still estimated to be only 5%, 20% and 49%, respectively. In America and Japan the figure is 91%. In countries that have increased their use of air con, deaths have come down. In Spain the share of homes with air con rose from 5% in 1991 to more than 40% today. Over the same period the risk of death from heat on hot days fell by 30-60%.
European cities, % increase in risk of death on days with 99th percentile temperature
By region
Northern
Western
Eastern
Southern
Hotter places tend to have a greater mortality risk when temperatures rise. But Pierre Masselot and his colleagues at the London School of Hygiene and Tropical Medicine found that Europe’s cities vary widely in their vulnerability to heat. Accounting for differences in local temperatures, the riskiest cities tend to be some of the continent’s most built-up urban areas. Dark surfaces made of concrete and tarmac absorb and retain heat, which makes big cities, especially those with few green spaces, hotter than more rural areas (this is not always captured in air-temperature data that are based on modelling). Other building materials also play a role: the iconic grey zinc roofs in Paris bake the flats beneath them. The relative risk of death in Paris rises by 56% on 99th-percentile days, far more than in places with similar temperatures.
Italian cities fare particularly poorly: Bologna tops the risk table and among large cities Milan is worst. Why it suffers more than Rome, which endures similar heat, is unclear. One reason may be that Milan is one of the most polluted cities in Italy: although pollutants can cool a region, high levels of particulates also worsen heat’s effects on health. Italy’s ageing population may add to the risk—40% of heat-related deaths occur in people aged over 85.
European cities, % increase in risk of death, by temperature
By region
Northern
Western
Eastern
Southern
The researchers also found that Amsterdam and London are far deadlier in hot weather than other European cities with similar temperatures. In both London and Copenhagen, for example, the 99th-percentile daily average is about 22°C (although daily maximums are several degrees higher). In London that raises the death risk by 45%, in Copenhagen by 14%. On average, a 22°C day in London is as deadly as 28°C across other European cities. Places with more poverty also suffer more during heatwaves. Poorer areas tend to have less green space, worse housing and residents who are more vulnerable. An analysis by Carbon Brief, a climate-news website, found that people in the most deprived neighbourhoods in English cities were three times more likely to experience extreme heat than those in the least deprived ones.
Scorching summers might also mean warmer winters. That could bring down deaths related to cold weather, which in Europe outnumber those from heat. A separate study by Dr Massalot found that many cooler cities may see a reduction in the overall death rate from extreme temperatures over the next 25 years. But, if no changes are made, already hot cities in Europe will see big increases in excess deaths related to heat. Florence is among the places that are forecast to suffer the most: by 2050 its death rate from heat may triple compared with the level in 2010, to 105 deaths per 100,000 people. Even cooler cities will feel the heat. Dublin’s heat-related mortality rate could increase more than ten-fold, albeit from a much lower base. To save lives, Europe needs to find ways to keep cool over the summer.■
Heatwaves are not as visible as floods and earthquakes, but they can be just as deadly. A recent study estimated that a ten-day spell of extreme heat starting on June 23rd killed around 2,300 people in 12 European cities. The researchers say that climate change made the heatwave between 1°C and 4°C hotter, enough to explain two-thirds of the deaths. High temperatures cause heat stroke, strain the heart and worsen chronic illnesses such as diabetes. More red alerts were issued across Europe on August 10th.
Europe is both warming faster than most parts of the world and, compared with other rich regions, appears to be ill-equipped to cope. Since the mid-1990s average temperatures on the continent have risen by 0.53℃ per decade, more than double the global land average of 0.26℃. Changing weather patterns have created more frequent and intense heatwaves. Europe’s efforts to cut air pollution over the past few decades have also raised temperatures, as some pollutants reflect sunlight back into space. And the fact that some of Europe is in the Arctic matters, too. The Arctic is the fastest-warming region on Earth; as ice melts it reflects less sunlight, speeding up the process.
But European cities appear to suffer more than cities in other rich regions even when peak temperatures are similar. Data from Kai Chen, of the Yale School of Public Health, and his colleagues shows that, when comparing cities with similar climates, the increase in mortality on days with temperatures in the 99th percentile for that location is far higher in Europe than in Asia or the Americas. For example, Turin, in northern Italy, and Toronto, Canada’s biggest city, have similar temperatures on their hottest days. But the risk of death on these days rises by more than 50% in Turin compared with 14% in Toronto.
Europe’s lack of air conditioning is surely part of the problem. The share of homes with air con in Britain, the Netherlands and Italy is still estimated to be only 5%, 20% and 49%, respectively. In America and Japan the figure is 91%. In countries that have increased their use of air con, deaths have come down. In Spain the share of homes with air con rose from 5% in 1991 to more than 40% today. Over the same period the risk of death from heat on hot days fell by 30-60%.
European cities, % increase in risk of death on days with 99th percentile temperature
By region
Northern
Western
Eastern
Southern
Hotter places tend to have a greater mortality risk when temperatures rise. But Pierre Masselot and his colleagues at the London School of Hygiene and Tropical Medicine found that Europe’s cities vary widely in their vulnerability to heat. Accounting for differences in local temperatures, the riskiest cities tend to be some of the continent’s most built-up urban areas. Dark surfaces made of concrete and tarmac absorb and retain heat, which makes big cities, especially those with few green spaces, hotter than more rural areas (this is not always captured in air-temperature data that are based on modelling). Other building materials also play a role: the iconic grey zinc roofs in Paris bake the flats beneath them. The relative risk of death in Paris rises by 56% on 99th-percentile days, far more than in places with similar temperatures.
Italian cities fare particularly poorly: Bologna tops the risk table and among large cities Milan is worst. Why it suffers more than Rome, which endures similar heat, is unclear. One reason may be that Milan is one of the most polluted cities in Italy: although pollutants can cool a region, high levels of particulates also worsen heat’s effects on health. Italy’s ageing population may add to the risk—40% of heat-related deaths occur in people aged over 85.
European cities, % increase in risk of death, by temperature
By region
Northern
Western
Eastern
Southern
The researchers also found that Amsterdam and London are far deadlier in hot weather than other European cities with similar temperatures. In both London and Copenhagen, for example, the 99th-percentile daily average is about 22°C (although daily maximums are several degrees higher). In London that raises the death risk by 45%, in Copenhagen by 14%. On average, a 22°C day in London is as deadly as 28°C across other European cities. Places with more poverty also suffer more during heatwaves. Poorer areas tend to have less green space, worse housing and residents who are more vulnerable. An analysis by Carbon Brief, a climate-news website, found that people in the most deprived neighbourhoods in English cities were three times more likely to experience extreme heat than those in the least deprived ones.
Scorching summers might also mean warmer winters. That could bring down deaths related to cold weather, which in Europe outnumber those from heat. A separate study by Dr Massalot found that many cooler cities may see a reduction in the overall death rate from extreme temperatures over the next 25 years. But, if no changes are made, already hot cities in Europe will see big increases in excess deaths related to heat. Florence is among the places that are forecast to suffer the most: by 2050 its death rate from heat may triple compared with the level in 2010, to 105 deaths per 100,000 people. Even cooler cities will feel the heat. Dublin’s heat-related mortality rate could increase more than ten-fold, albeit from a much lower base. To save lives, Europe needs to find ways to keep cool over the summer.■
Heatwaves are not as visible as floods and earthquakes, but they can be just as deadly. A recent study estimated that a ten-day spell of extreme heat starting on June 23rd killed around 2,300 people in 12 European cities. The researchers say that climate change made the heatwave between 1°C and 4°C hotter, enough to explain two-thirds of the deaths. High temperatures cause heat stroke, strain the heart and worsen chronic illnesses such as diabetes. More red alerts were issued across Europe on August 10th.
Europe is both warming faster than most parts of the world and, compared with other rich regions, appears to be ill-equipped to cope. Since the mid-1990s average temperatures on the continent have risen by 0.53℃ per decade, more than double the global land average of 0.26℃. Changing weather patterns have created more frequent and intense heatwaves. Europe’s efforts to cut air pollution over the past few decades have also raised temperatures, as some pollutants reflect sunlight back into space. And the fact that some of Europe is in the Arctic matters, too. The Arctic is the fastest-warming region on Earth; as ice melts it reflects less sunlight, speeding up the process.
But European cities appear to suffer more than cities in other rich regions even when peak temperatures are similar. Data from Kai Chen, of the Yale School of Public Health, and his colleagues shows that, when comparing cities with similar climates, the increase in mortality on days with temperatures in the 99th percentile for that location is far higher in Europe than in Asia or the Americas. For example, Turin, in northern Italy, and Toronto, Canada’s biggest city, have similar temperatures on their hottest days. But the risk of death on these days rises by more than 50% in Turin compared with 14% in Toronto.
Europe’s lack of air conditioning is surely part of the problem. The share of homes with air con in Britain, the Netherlands and Italy is still estimated to be only 5%, 20% and 49%, respectively. In America and Japan the figure is 91%. In countries that have increased their use of air con, deaths have come down. In Spain the share of homes with air con rose from 5% in 1991 to more than 40% today. Over the same period the risk of death from heat on hot days fell by 30-60%.
European cities, % increase in risk of death on days with 99th percentile temperature
By region
Northern
Western
Eastern
Southern
Hotter places tend to have a greater mortality risk when temperatures rise. But Pierre Masselot and his colleagues at the London School of Hygiene and Tropical Medicine found that Europe’s cities vary widely in their vulnerability to heat. Accounting for differences in local temperatures, the riskiest cities tend to be some of the continent’s most built-up urban areas. Dark surfaces made of concrete and tarmac absorb and retain heat, which makes big cities, especially those with few green spaces, hotter than more rural areas (this is not always captured in air-temperature data that are based on modelling). Other building materials also play a role: the iconic grey zinc roofs in Paris bake the flats beneath them. The relative risk of death in Paris rises by 56% on 99th-percentile days, far more than in places with similar temperatures.
Italian cities fare particularly poorly: Bologna tops the risk table and among large cities Milan is worst. Why it suffers more than Rome, which endures similar heat, is unclear. One reason may be that Milan is one of the most polluted cities in Italy: although pollutants can cool a region, high levels of particulates also worsen heat’s effects on health. Italy’s ageing population may add to the risk—40% of heat-related deaths occur in people aged over 85.
European cities, % increase in risk of death, by temperature
By region
Northern
Western
Eastern
Southern
The researchers also found that Amsterdam and London are far deadlier in hot weather than other European cities with similar temperatures. In both London and Copenhagen, for example, the 99th-percentile daily average is about 22°C (although daily maximums are several degrees higher). In London that raises the death risk by 45%, in Copenhagen by 14%. On average, a 22°C day in London is as deadly as 28°C across other European cities. Places with more poverty also suffer more during heatwaves. Poorer areas tend to have less green space, worse housing and residents who are more vulnerable. An analysis by Carbon Brief, a climate-news website, found that people in the most deprived neighbourhoods in English cities were three times more likely to experience extreme heat than those in the least deprived ones.
Scorching summers might also mean warmer winters. That could bring down deaths related to cold weather, which in Europe outnumber those from heat. A separate study by Dr Massalot found that many cooler cities may see a reduction in the overall death rate from extreme temperatures over the next 25 years. But, if no changes are made, already hot cities in Europe will see big increases in excess deaths related to heat. Florence is among the places that are forecast to suffer the most: by 2050 its death rate from heat may triple compared with the level in 2010, to 105 deaths per 100,000 people. Even cooler cities will feel the heat. Dublin’s heat-related mortality rate could increase more than ten-fold, albeit from a much lower base. To save lives, Europe needs to find ways to keep cool over the summer.■