The excessive burning of fossil fuels and mismanagement of forests and soils have released vast amounts of terrestrial and fossil carbon into the atmosphere throwing the global carbon cycle, that underpins life as we know it, out of the balance. But there are ways we can help rebalance the cycle. Of course we have to stop burning so many fossil fuels. We can also pull the excess carbon out of the atmosphere and give it back to the soil. Unlike more carbon in the atmosphere, more carbon in the soil is good for us. It makes soil healthy! Healthy soil makes healthy food and that's good for everyone.
The global carbon cycle refers to the exchanges of carbon within and between four major reservoirs: the atmosphere, the oceans, land, and fossil fuels. Carbon may be transferred from one reservoir to another in seconds (e.g., the fixation of atmospheric CO2 into sugar through photosynthesis) or over millennia (e.g., the accumulation of fossil carbon (coal, oil, gas) through deposition and diagenesis of organic matter). -R.A. Houghton, in Treatise on Geochemistry
Resources:
The Soil Story, Kiss the Ground
Nasa, Global Carbon Cycle Gas Visualization
Compost and Carbon Sequestration, The Marin Carbon Project
Biomass: Impact on Global Carbon Cycle and Green House Gas Emissions