Mounting science is painting a very bleak picture of a future of soaring temperatures, and the accompanying death toll those soaring temperatures will demand.
New research has given us the first solid prediction of how more heatwaves like the one that's struck Europe this year will affect future death rates, finding tropical heatwaves in some areas could one day send the mortality rate skyrocketing by as much as 2,000 percent.
As temperatures climb, bodies overheat, and the chances of harsh environmental conditions (such as smog) go up. Neither is good for our health, and frequent summer heatwaves can often be too much for some people to bear.
Last month in Montreal, the deaths of 70 people were blamed on a rise in temperatures. As global warming makes these kinds of weather events more common, it's important to consider the toll it will take on our health.
"Worryingly, research shows that it is highly likely that there will be an increase in their frequency and severity under a changing climate, however, evidence about the impacts on mortality at a global scale is limited," says co-author Antonio Gasparrini from the London School of Hygiene & Tropical Medicine.
With an international team of researchers, Gasparrrini created a database of daily measurements of temperatures and mortalities from the start of 1984 to the end of 2015 for 412 communities around the globe.
They used these numbers to predict mortality rates extending back to 1977 and all the way forward to the end of this century, varying the outcomes based on several scenarios.
For the 'business-as-usual' scenario, the news is grim.
"This research, the largest epidemiological study on the projected impacts of heatwaves under global warming, suggests it could dramatically increase heatwave-related mortality, especially in highly-populated tropical and sub-tropical countries," says Gasparrini.
By 2080, there's an outside chance that Colombia could see an increase in heatwave deaths of more than 30 times today's numbers. For Brazil and the Philippines, the numbers are only slightly less concerning, at around 10 to 20 times the current mortality rate.
Major cities in the US and Australia could see at least four times the number of deaths.
If a silver lining can be found on this research, it's that the same models also suggest these hypothetical numbers needn't be so high.
"The good news is that if we mitigate greenhouse gas emissions under scenarios that comply with the Paris Agreement, then the projected impact will be much reduced," says Gasparrini.
Populations will almost certainly continue to adapt to rising temperatures as well.
Urban planning might provide infrastructure for cooler living and working conditions. Healthcare could adjust to intervene earlier in conditions where heat stress carries risks. Individuals could grow more aware of the dangers and modify behaviours.
Measures like these would have a significant impact on that bottom line, limiting casualties.
But even with a best-case scenario, where countries stick to the Paris agreement and take heatwaves seriously enough to implement programs to mediate their impact, we can expect to see a doubling in deaths in some tropical countries.
That's not as bad as it could be, but it still means we can expect more deadly summers like 2018's to be hitting our planet.
Realistically, healthcare programs and urban infrastructure changes won't be universal, and governments aren't exactly united in their stance on climate change. Developing countries or nations with unequal distributions of wealth might be less likely to implement government policies devoting resources to reducing the impact of heatwaves.
Countries like China face more than just the ravages of heat stress. A separate study carried out by researchers at MIT suggests the North China Plain could face heatwaves that make it all but uninhabitable.
Farming in the area adds a vast amount of water to the atmosphere, creating a blanket of vapour that exacerbates the local greenhouse effect, adding half a degree to the temperature.
High humidity coupled with high temperature makes cooling down almost impossible, since in those conditions sweat can no longer evaporate. For the 400 million people who call the plains home, this could be a catastrophe.
"This spot is going to be the hottest spot for deadly heatwaves in the future, especially under climate change," says the study's lead author, Elfatih Eltahir.
No matter how we look at it, our warming planet is going to be a deadly one, especially for the poor and the sick.
This research was published in PLOS Medicine.