Autotrophs participate in the carbon cycle by fixing carbon dioxide to produce the biomass that all other organisms use for life. Four autotrophic carbon-fixation pathways were already known and ...

Rivers, lakes and wetlands are important factors for climate change, which should have a place in conceptual models of the global carbon cycle. A broader concept of a 'boundless carbon cycle ...

If Earth's history were a calendar year, humans would not appear until the last few minutes before midnight on Dec. 31.