Carbon fixation is the process where carbon is trapped in fossil fuel or sedimentary rock for millions of years. Fixed carbon does not contribute to to global warming if we prevent it's Tralee to the atmosphere
Carbon sink is a reservoir that stores carbon. The build up of CO2 in the atmosphere is moderated by carbon sink, which removed carbon from the atmosphere and stores it for a period of time. The oceans m, growing vegetation, soil, and some sedimentary rock (ex. Limestone) are carbon sinks because more carbon move into them then out of them.
Carbon source is an activity or a location that gives off more CO2 the it absorbs, examples of carbon sources are volcanoes, burning forests, limestone weathering, decaying organic matter, the burning of fossil fuels and breathing, all of which release CO2 into the atmosphere.