Thousands of heat-related deaths in more than a dozen major US cities may be avoidable if global temperatures are kept under the Paris Climate Goals, according to a new study published in Science Advances.
Combing through national climate and health data, a team of scientists and epidemiologists calculated the number of heat-related deaths that would occur under three different temperature increase scenarios. If mitigation requirements as set forth by the Paris agreement aren’t followed, they say that the nation may see an additional 110 to 2,700 heat-related deaths every year during extreme heatwaves.
"We are no longer counting the impact of climate in change in terms of degrees of global warming, but rather in terms of [the] number of lives lost,” said study author Dann Mitchell in a statement. "Our study brings together a wide range of physical and social complexities to show just how human lives could be impacted if we do not cut carbon emissions. Considering the US citizens that will be adversely affected by increasing global temperatures, we strongly encourage them to hold their politicians to account.”
Established in 2015, the Paris agreement was an international decision to keep global average temperatures well below 2°C (3.6°F) above pre-industrial levels. Shortly after winning the 2016 election, the Trump administration withdrew the US pledge (but effective withdrawal is not until 2020). Nations in the agreement must resubmit their support every five years and, as the researchers note, studies such as this could have implications for political decisions to advance nationalistic climate decisions.
Fatalities vary by location and climate scenario. For example, if the world stays below the 2°C threshold the US could avoid between 70 and 1,980 deaths – that number jumps to between 110 and 2,270 if the world is able to sustain levels below 1.5°C (2.7°F). Furthermore, the authors assume current mitigation strategies remain in place and are quick to note that population changes and adaptation investments would change these projections.
"If global temperature rise is reduced to 1.5°C from where we are headed, the cities' exposure to extreme heat would decrease and up to thousands of annual heat-related deaths could be avoided per city,” said lead author Eunice Lo. "Strengthened climate actions are needed as they would substantially benefit public health in the United States."
Climate change is expected to increase heat-related deaths on every human-populated continent, expressing a “clear need” to strengthen attempts at curbing greenhouse gas emissions. At the current rate, researchers suggest the planet is set to see an increase of 2.6° to 3.1°C above preindustrial levels by the end of this century.
The researchers write that in addition to standing by international goals, increasing the use of passive cooling strategies and being aware of heat-related health risks will help provide resilience in a warming world.
2