Our Blood is Changing Because of Climate Change, and It's More Serious Than You Think.
Here’s a startling revelation: the carbon dioxide (CO2) we’re pumping into the atmosphere isn’t just altering the planet—it’s quietly transforming our bodies too. A groundbreaking study suggests that rising atmospheric CO2 levels are leaving a measurable mark on human blood chemistry. But here’s where it gets controversial: while these changes aren’t harmful yet, they could push our bodies to the brink of what’s considered healthy by the end of this century. Should we be worried? Let’s dive in.
Scientists analyzed two decades of health data from a U.S. population database and discovered shifts in blood chemistry that align eerily well with increasing CO2 exposure. According to their models, if current trends persist, certain blood markers could hit the upper limits of today’s healthy range by around 2076. And this is the part most people miss: it’s not just about CO2 levels rising—it’s about how our bodies are struggling to keep up with this unprecedented change.
Respiratory physiologist Alexander Larcombe from Curtin University puts it bluntly: ‘What we’re seeing is a gradual shift in blood chemistry that mirrors the rise in atmospheric CO2, the very driver of climate change.’ Specifically, average bicarbonate levels—a byproduct of CO2 in the blood—could approach dangerous thresholds within 50 years. Calcium and phosphorus levels, essential for bone health, might also dip toward the lower end of healthy ranges later this century.
To put this in perspective, Earth’s atmospheric CO2 levels remained stable around 280 to 300 parts per million (ppm) for the entire 150,000-year history of Homo sapiens. But in just a few decades, we’ve skyrocketed from 369 ppm in 2000 to 420 ppm today. That’s a shift our bodies weren’t designed to handle.
Here’s how it works: when we breathe in CO2, our bodies convert it into bicarbonate, a compound that helps regulate blood pH. Normally, this is a good thing—it keeps our blood acidity in check. But Larcombe and his colleague, retired geoscientist Phil Bierwirth, theorized that bicarbonate could also act as a tracer for atmospheric CO2 in our blood. They analyzed data from the U.S. National Health and Nutrition Examination Survey (NHANES), which tracked blood samples from 7,000 Americans every two years between 1999 and 2020.
The results were striking: average blood bicarbonate levels rose by 7% during the study period, paralleling the rise in atmospheric CO2. Meanwhile, calcium and phosphorus levels dropped by 2% and 7%, respectively. Why? When CO2 dissolves in the bloodstream, it disrupts the body’s acid-base balance. To compensate, the kidneys conserve bicarbonate, and bones release minerals like calcium and phosphorus to neutralize excess acidity. It’s a delicate dance—one that’s being thrown off by our rapidly changing environment.
But here’s the kicker: Bierwirth suggests our bodies aren’t adapting to these changes. ‘It appears we are adapted to a range of CO2 in the air that may now have been surpassed,’ he says. ‘As CO2 in the air is now higher than humans have ever experienced, it appears to be building up in our bodies. Maybe we can never adapt, which makes limiting atmospheric CO2 vitally important.’
For now, these shifts are small and within the body’s tolerable range. But the parallel rise with atmospheric CO2 is undeniable. If this trend continues, we could see widespread physiological changes at the population level. And that raises a critical question: Are we pushing our bodies to the edge of what they can handle?
This research, published in Air Quality, Atmosphere & Health, isn’t just a scientific curiosity—it’s a wake-up call. It challenges us to rethink our relationship with the planet and our own health. So, what do you think? Are we underestimating the impact of climate change on our bodies? Let’s hear your thoughts in the comments.
