And here's the thing: you have to go back about 15 million years to find a time when CO2 levels You have to go back about 30 million years to find a time when CO2 levels were double what they are today.
さてここで CO2量が現代と同じくらいの 時代を見つけるには 1500万年ぐらい遡らないといけません ２倍の量の時代を見つけるには 3000万年遡らないと