Published: April 21, 2020 By
Students taking a test

New CU Boulder research finds that an anticipated rise in carbon dioxide concentrations in our indoor living and working spaces by the year 2100 could lead to impaired human cognition.

“These results have the potential to impact just about everybody on the planet who breathes,” said Kris Karnauskas, CIRES Fellow, associate professor at CU Boulder and lead author of the new study published in GeoHealth. “Even in 2020, we're still just scratching the surface at the possible range of impacts that climate change could have on humans and especially on our health.”

By the end of the century, people could be exposed to indoor CO2 levels up to 1400 parts per million—more than three times today's outdoor levels, and well beyond what humans have ever experienced.

When people breathe air with high CO2 levels, the CO2 levels in the blood rise, reducing the amount of oxygen that reaches our brains. Studies show that this can increase sleepiness and anxiety, and impair cognitive function. 

With people around the world spending more time indoors due to efforts to contain the spread of novel coronavirus (COVID-19), the research seems quite timely.

“It's bringing building ventilation to a whole new level of awareness and understanding,” said Shelly Miller, co-author of the new study and professor of engineering. “Spaces where we know that carbon dioxide accumulates is a sign of poor ventilation. And most of the COVID-19 transmission is happening in crowded, poorly ventilated environments.” 

Building ventilation, heating and air conditioning, however, already account for one third of carbon emissions in the United States. This means that improved ventilation could further increase carbon emissions and exacerbate the problem, if not addressed with renewable, carbon-neutral energies. 

This study is also unique in that it combines three different scientific disciplines all working on the same problem at the same time: a climate scientist, air quality engineer and a cognitive neuroscientist.

“This is not the type of challenge that just a climate scientist can solve by themselves,” said Karnauskas.

Read more about the human cognition and CO2 study.

The additional co-author of this study is Anna Shapiro at the University of Pennsylvania.