CO2 is a pollutant

We are on track for 1000ppm by 2100 if we do nothing.  At 1,000ppm, human cognitive ability drops by 21%.  

Outdoor CO2 already reaches 500ppm regularly in industrial cities; indoors, in poorly ventilated homes or school workplaces, it can regularly exceed 1,000ppm. A study of bedrooms in Denmark found that overnight concentrations of CO2 exceeded 2,000ppm, with measurable effects on student’s performance the following day.

The global warming deniers argue that CO2 is not a pollutant and therefore it's presence in the biosphere doesn't matter.  However, that just is not true.

  Air pollution over London. Rising levels of outdoor pollution will mean levels rising indoors too. Photograph: Nick Ansell/PA 

Indoor levels of carbon dioxide could be clouding our thinking and may even pose a wider danger to human health, researchers say.

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However, the authors of the latest study – which reviews current evidence on the issue – say there is a growing body of research suggesting levels of CO2 that can be found in bedrooms, classrooms and offices might have harmful effects on the body, including affecting cognitive performance.

It's going to affect our brain.

At higher levels, CO2 clouds the mind: it makes us slower and less likely to develop new ideas, it degrades our ability to take in new information, change our minds, or formulate complex thoughts.

Global atmospheric CO2 levels passed 400 parts per million in 2016, and despite global agreements to keep runaway climate change under control, little action has been taken. The very worst-case scenario – AKA business as usual, which is the track we’re on – predicts atmospheric CO2 concentration of 1,000ppm by 2100. At 1,000ppm, human cognitive ability drops by 21%.

It's important to understand that even now your indoor concentration of CO2 can be equal to or greater than 1000ppm.  

This isn’t merely a problem for the future – as if that would make it better. As we come to understand more about the effects of CO2, we have been measuring more of it, and finding that as it increases outside, it increases inside, too. Outdoor CO2 already reaches 500ppm regularly in industrial cities; indoors, in poorly ventilated homes or school workplaces, it can regularly exceed 1,000ppm. A study of bedrooms in Denmark found that overnight concentrations of CO2 exceeded 2,000ppm, with measurable effects on student’s performance the following day.

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Even if we meet the most stringent targets set at the Paris agreements in 2015, 2100 will bring atmospheric CO2 levels of 660ppm – with around a 15% decrease in average brainpower. It’s possibly one of the most tragic ironies of the whole sorry business that climate change is making it harder for us to think, just when we need new and bold ideas to deal with its effects.