Global warming driven by greenhouse gas emissions wouldn’t just be bad for the planet and its oceans: it would also make Homo sapiens measurably less sapient. Research on seamen aboard submarines and in astronaut tests have confirmed that CO2 builds up in confined spaces, to limit the supply of oxygen to the brain. As this happens, people in such conditions have problems responding to any stimulus or even recognising a threat.
carbon dioxide concentrations – at around 280 ppm for most of human history, but already past the 400ppm mark – will rise to 930ppm by the end of the century. If that happens, then indoor concentrations could quickly reach 1400ppm. And this could, on some research findings, begin to compromise what psychologists call high-level cognitive domains. So basic decision-making ability could falter by a quarter, and concentration on complex problems by 50%.
— source climatenewsnetwork.net | Apr 27, 2020