# data[].attributes.body
Earth had almost no atmosphere. The surface was molten. As Earth cooled, an atmosphere formed mainly from gases spewed from volcanoes. It included hydrogen sulfide, methane, and ten to 200 times as much carbon dioxide as today’s atmosphere. After many years the surface began to harden.

# data[].attributes.body
There was no oxygen gas on Earth. Oxygen was only in compounds such as water. Complex chemical reactions in the young oceans transformed carbon-containing molecules into simple, living cells that did not need oxygen to live.

# data[].attributes.body
tiny photosynthetic organisms produced enough oxygen to react with the methane in the atmosphere, transforming it forever. About two billion years ago, the methane haze cleared and the sky turned blue

# data[].attributes.body
in the late Proterozoic, oxygen levels in the oceans and atmosphere increased dramatically. The oxygen boom favored the evolution of lifeforms that could use oxygen to create energy. For other organisms, oxygen was poisonous, and they were forced into extreme airless habitats or into extinction

# data[].attributes.body
on modern earth there is much more wildlife (living things). Temperatures have cooled since the former eons (until global warming) polar ice caps have increased in size.