history of earth
Kuvakäsikirjoitus Teksti
- the atmosphere was mostly carbon dioxide and with little or no oxygen.
- the air was healthier and richer than the air humans breathe today
- scientist discovered that carbon dioxide levels was 30% lower during the ice age
- human activities were already dramatically increasing the carbon dioxide in the atmosphere.
- In our modern atmosphere our oxygen levels are decreasing due to new development of factories causing pollution
- Space is different from earth because there is no oxygen although there is bits of helium and nitrogen.
Yli 30 miljoonaa kuvakäsikirjoitusta luotu