Ancient microbes caused Earth’s first ever global warming

 作者:亢瘅     |      日期:2019-03-07 11:03:01
Tom Murphy/Getty By Alice Klein We’re not the first living beings to drastically alter Earth’s climate. The earliest photosynthetic microorganisms belched out enough methane to warm the planet by 15°C. This bout of global warming may have saved Earth from freezing over, and created a comfortable climate for early organisms. When Earth formed 4.5 billion years ago, the sun was 25 per cent dimmer than it is today. This suggests the early planet should have been a big snowball, but geological evidence indicates it was just as warm as now,