Researchers at the Harvard School of Public Health have found that carbon dioxide (CO2) has a direct and negative impact on human cognition and decision-making, according to a new study, as reported by ThinkProgress.
These impacts have been observed at carbon dioxide levels that most Americans are routinely exposed to today inside classrooms, offices, homes, planes and cars.
Although carbon dioxide levels are higher indoors than outdoors, increasing overall levels in the atmosphere could have detrimental impacts on people outdoors as well. The study found that the largest effects were seen for crisis response, information usage and strategy, all of which are indicators of higher level cognitive function and decision-making.
The Harvard study confirms the findings of a 2012 Lawrence Berkeley National Laboratory (LBNL) study, which found “statistically significant and meaningful reductions in decision-making performance” in test subjects as carbon dioxide levels rose.
NASA also has observed carbon dioxide-related health impacts on International Space Station (ISS) astronauts at much lower carbon levels than expected and has identified a mechanism by which levels could affect the brain, ThinkProgress reports. That’s why NASA already has lowered the maximum allowable carbon dioxide levels on the space station.
For most of human existence, carbon dioxide levels in the air were in a fairly narrow and low range of 180 to 280 parts per million, ThinkProgress reports. Humans also have historically spent little time indoors, which meant we were not exposed to high, sustained carbon dioxide levels.
In recent decades, however, carbon dioxide levels have risen dramatically, and measured outdoor levels in major cities like Phoenix and Rome can be even higher than the global average. That’s because carbon dioxide “domes” form over many cities primarily due to emissions from traffic and local weather conditions.
In May, President Obama announced a series of actions aimed at improving the country’s understanding of the health impacts of climate change in the U.S., in response to calls from leading medical practitioners who have found direct and indirect links between it and an increase in respiratory illnesses, cardiovascular disease and heat-related deaths.
There already is mounting evidence that taking action to fight climate change has clear public health benefits. A 2015 study by researchers at Syracuse and Harvard Universities found that the new carbon emissions standards that were proposed last year for coal-fired power plants in the U.S. would substantially improve human health and prevent more than 3,000 premature deaths per year.