New report details rising cost of climate change to human health

Maria Walawender: It’s really a both/and. So, incredibly hot heat wave days can be quite dangerous for people, but we’re also starting to learn more about the dangers of prolonged exposure to heat, particularly in places that aren’t used to it. So, when those folks are now exposed to dangerous heat waves days, or just prolonged periods of extended heat, it’s quite taxing on their systems, and they often don’t have the types of measures in place to keep themselves safe.

As with many things related to climate change, the impacts are not evenly spread throughout the world. We see higher rates of heat-related mortality in Africa, particularly sub-Saharan Africa, which is a historically low emitter [of] greenhouse gas emissions. And while we do see heat-related deaths, in most corners of the globe now, they are higher in places that have traditionally had very low emissions.  

We are increasingly tracking, not just acute, but also long-term effects of a variety of climate impacts. On heat, specifically, we know that extreme heat exposure is quite dangerous during pregnancy and in early age. That can have impacts on pre-term delivery or an increased risk of stillbirth. But we’re also taking a somewhat more “systems” view. We know that in 2024 alone, record-breaking heat led to the loss of about 650 billion potential work hours, [with] the agricultural sector most-heavily impacted. And when we couple this with the record-breaking amount of land experiencing drought in 2024, we’ve already [seen] that an additional 125 million people are reporting that they’re experiencing moderate or severe food insecurity specifically related to those heat wave days and drought months.

Despite the fact that climate change is an incredibly large, pervasive and complex issue, when we implement the types of solutions that we know work, we see the impact both immediately and in the long term. And, so, a good example of this is when we do transition away from dirty fossil fuels, like coal, the air that we breathe is cleaner. So, we have reduced our coal usage in certain parts of the world. And, in doing so, we’ve prevented about 160,000 deaths per year just due to the cleaner air that folks are breathing.

There are about two and a half million deaths per year from the burning of fossil fuels. That includes both coal, liquid, and gas forms of fossil fuels. And there are another few million deaths from burning things like biomass and other sources of particulate matter from human activity.

It’s a good question. It’s a bit hard to quantify a specific number of how many people died due to climate change because it is so pervasive and hard to attribute specifically back [to] some of the more indirect effects. But what we do know is [that there are] half a million deaths per year just from heat. We’re seeing hundreds of thousands of deaths from exposure to wildfire smoke. We’re seeing millions of deaths from the direct burning of fossil fuels and the dirty air that that creates. So, climate change is leading to millions of deaths per year, both directly and indirectly, through its impact on a variety of systems and social determinants of our health.

I think what’s really true about climate change is [that] it’s impacting every corner of the world. So, you don’t have to travel too far to experience it firsthand. I work really closely with incredible collaborators of the Landsat Countdown who are based all around the world, including in Jamaica, who do work specifically focused on the hazards and  vulnerabilities of small island developing states. And just over the last few days, they’ve also been on the receiving end of an incredibly dangerous hurricane that is likely, at least in part, a result of the climate change that they’re studying.