Scientists that dedicate their entire lives to studying this, have made it clear: to avert the worst effects of climate change, the levels of CO2 in the atmosphere need to be at 350 parts per million (ppm). Right now we are at 391ppm. If we keep burning at the rate we are now, we will be at 500ppm by 2050. This would make earth a completely different planet, uninhabitable for most species. We can't let that happen.Oh, really? In that case, we must be careful about our puppies, kittens, and other pets not to get into our house, to protect their life. ;-) The reality is that 500 ppm is totally harmless for all known species on the planet - and actually well below the average concentrations we experience in our everyday life.
It may be useful to summarize some important values of the CO2 concentration:
- 150 ppm - the minimum concentration below which many plants may face problems to run photosynthesis and stop growing
- 180 ppm - the concentration during ice ages
- 280 ppm - the concentration during interglacials, i.e. also the pre-industrial concentration around 1750
- 391 ppm - the concentration today
- 500 ppm - the concentration around 2060-2070 (unlikely that before 2050 as they claim)
- 560 ppm - the concentration around 2080-2110 (the "doubled CO2" relatively to the pre-industrial values) relevant for the calculations of climate sensitivity); a concentration routinely found outdoors today
- 700 ppm - the concentration in an average living room
- 900 ppm - concentration in an average kitchen
- 1,270 ppm - the concentration used to double the growth of Cowpea in a famous video
- 1,700 ppm - the average concentration in the Cretaceous 145-65 million years ago (early mammals came, plus figs, magnolias, birds, modern sharks)
- 4,500 ppm - the concentration 444-416 million years ago (the Silurian dominated by corals and mosses); see other values in geological epochs
- 10,000 ppm - sensitive people start to feel weaker
- 40,000 ppm - the concentration of CO2 in the air we breath out
- 50,000 ppm - toxic levels at which the animals like us get weaker in hours; the value is 5 percent of the volume
- 180,000 ppm - the concentration of CO2 in exhausts of a healthy motor; that's 18 percent
- 1,000,000 ppm - pure CO2, just to make you sure what the units are
Children, this is what you may want to be worried about, iThink.