In a recent report scientists in Europe are sounding alarms about 'carbon sinks' becoming too saturated to continue to absorb CO2. They fear that, if left unchecked, the natural cycle of the atmosphere could be irreversibly altered, dramatically affecting our ability to exist on the planet.
Carbon sinks are reservoirs which provide long-term storage for the gas; oceans, rocks, and soil are natural sinks which researchers consider vital to maintaining the balance between carbon and oxygen in the atmosphere. Trees play an important role in collecting carbon into the soil, but scientists are concerned by two factors: 1) There are too few trees to compensate for the volume of carbon being ejected, by both man-made and natural processes, and 2) Those trees which do exist are mature-growth, which by virtue of age collect and store less carbon into their root systems.
Scientists also note that forest fires (which are more dangerous than ever, courtesy of mismanagement and/or neglect of the denser forests which exist) play a large part in this, not only due to the destruction of the carbon-absorbing trees but also for releasing previously-stored carbon. Volcanic activity is also credited by some with playing a role, albeit minor.
They conclude that if these carbon sinks reach saturation points-of-no-return CO2 will eventually pollute our atmosphere beyond breathable levels. While artificial carbon reservoirs continue to be developed and deployed, without the natural sinks doing their part it will only be a matter of time before the planet is overwhelmed, and oxygen-breathing species - including homo-sapiens - will experience severe drops in populations, if not outright extinctions.