Climate action could avert hundreds of heat-related deaths in these 15 US cities

Taking action to combat global warming can now be measured in lives saved rather than in degrees of temperature change. This is the result of a new study published Wednesday in the journal Science Advances, which has quantified the number of heat-preventable deaths that could be prevented in 15 US cities by actually meeting the global targets for reducing carbon emissions as opposed to continuing their usual activities.

One of the deadliest threats of the climate crisis is the extreme heat. It kills more Americans each year than any other weather event. When your body can no longer regulate its core temperature, it can result in heat exhaustion, stroke, heart attack, or a range of other health problems that can lead to premature termination. Climate change is expected to result in more heat waves back-to-back, made even more unbearable in cities through the urban heat island effect. Cities and neighborhoods with more asphalt trapping heat than their surrounding communities tend to experience warmer temperatures. These areas are often those of people of color and low-income residents.

By studying observed temperatures, mortality data and climate projections, researchers at the University of Bristol in the United Kingdom have calculated the estimated annual number of heat-related deaths in several major American cities, including New York , Atlanta, Los Angeles, Chicago and Houston. , and Seattle, according to three climate scenarios: If the world meets the minimum standards set by the historic 2015 Paris agreement (limiting global average temperatures to 2 degrees Celsius – 3.6 degrees Fahrenheit – from pre-industrial levels of here 2100), achieve a more ambitious goal touted by many scientists and communities most vulnerable to climate (stopping at 1.5 ° C or 2.7 ° F warming), and if we just continue to live normally ( and the first 3 degrees C, 5.4 degrees F, warming).

Adapted from Lo et al 2019, Science Advances

Heat death at +1.5 ° C (+ 2.7 ° F) warming
More and more scientific evidence has shown that the 1.5 ° C warming is the threshold from which we can avoid the most severe damage. And yes, aboriginal peoples, small island nations and other countries most affected by climate change have been saying this for years. Now supported by the historic report of the Intergovernmental Panel on Climate Change (IPCC) last year, it is this ambitious goal that most climate activists would like to see take action.

• Most deaths due to heat per 100 000 inhabitants: Miami (248)
• Less deaths due to heat per 100,000 inhabitants: Phoenix (14)
• The highest percentage of deaths due to heat avoided per 100 000 inhabitants compared to + 3 ° C: Phoenix (58% less deaths)

Deaths due to heat at +2 ° C (+3.6 ° F) from warming
This is the difficult target set out in the Paris agreement. Back to 2015: After more than two decades of negotiations, world leaders have finally decided to work together to avert a climate catastrophe. Each country is committed to reducing its greenhouse gas emissions in order to prevent the world from warming beyond 2 degrees Celsius above pre-industrial temperatures.

Since then, of course, the most ambitious 1.5 degrees Celsius have become a prime target. The question is whether this is realistic, as many countries have already fallen behind the initial promises of their Paris agreement.

• Most deaths due to heat per 100 000 inhabitants: Miami (323)
• Less deaths due to heat per 100,000 inhabitants: Phoenix (20)
• Highest percentage of heat-related deaths averted per 100,000 population compared to + 3 ° C: Phoenix, Seattle (39% less deaths)

Deaths due to heat at +3 ° C (+6.5 ° F) of warming
Four years after Paris, the world is in the process of seeing the average global temperature rise significantly by 3 ° C (6.5 ° F). According to the study, this level of warming could make a deadly difference in many cities studied.

• Five cities with the highest number of heat deaths per 100,000 population: Miami (520), Detroit (204), St. Louis (113), Seattle (103), Philadelphia (95)

What makes some places more vulnerable to heat deaths than others?

The researchers say that the probability of a city suffering heat-related deaths is largely related to factors such as the density of a city's population density, its larger population, such as the elderly, and his readiness for the heat. the emergencies.

The city of New York, for example, has a lot to gain by keeping up with climate goals in the event of a heat wave over a 30-year period – 1,980 deaths due to total heat according to a scenario of 1.5 ° C against 5 798 deaths due to the total heat at 3 ° C. scenario. Of course, it has the largest population of places examined, so it goes without saying that it has one of the largest accounts of the number of lives saved if we are able to curb global warming.

There are also regional differences in how each city would rank according to its culture and location. Some areas of the United States, including many more northerly cities, will experience a higher average temperature increase that they may not be prepared for. Others, like Phoenix, have a higher percentage of the population already equipped with air conditioning.

What can cities do to reduce the number of deaths from heat?

Scientists claim that the purpose of this study is to inform policymakers before the deadline of the signatory countries of the Paris Agreement to present renewed climate commitments in 2020. In addition to reducing emissions, cities can do a lot to reduce the risk of heat. HIV / AIDS-related deaths, such as educating the public about heat-related illness symptoms, improving infrastructure and public health programs, and expanding access to air conditioning.

Places like New York are already taking steps to calm down, including ensuring that heat-absorbing urban spaces have more green space and ensuring that older people, communities of color and other populations vulnerable people have access to air conditioning. The city is also committed to reducing its carbon emissions by adopting ambitious environmental policies.

Rather than thinking of climate change solely in terms of your metropolitan area, researchers hope that these figures will inspire leaders to take action to combat climate change and badess its long-term effects. "If this happens in a country like America, you can bet that its impact on developing countries is much worse," said co-lead author Dann Mitchell, climate specialist in Bristol.