DWQA Questions › Tag: ecologyFilter:AllOpenResolvedClosedUnansweredSort byViewsAnswersVotesScientists have estimated that a CO2 level below about 110 ppm cannot sustain life. Is that a reasonable assessment?ClosedNicola asked 3 years ago • Extraterrestrial Agenda303 views0 answers0 votesThe record of CO2 levels over the last 140 million years shows that the level of CO2 has been dropping steadily as a long-term trend, from when it was 4000 ppm, almost 10 times higher than today. Recently, it has increased after approaching the 110 ppm “danger zone” to reach about 415 ppm. What is the desirable range to have? Is the CO2 level dangerously high?ClosedNicola asked 3 years ago • Extraterrestrial Agenda305 views0 answers0 votes