Soils may absorb less CO2 than thought

/soils-may-absorb-less-co2-than-thought

  • Soils may absorb less #CO2 than thought | Climate News Network
    http://www.climatenewsnetwork.net/2014/05/soils-may-absorb-less-co2-than-thought

    Scientists from the US, China and Ireland may have settled one big question about climate change: don’t rely on the soil microbes to help damp down the temperatures. They report in Science that as carbon dioxide levels rise, and temperatures increase, so does the turnover of carbon in the soil.

    That means the hope that global warming must mean more energetic plant growth and therefore greater carbon uptake in the soil, in a cycle that engineers like to call negative feedback, looks a bit forlorn.

    Kees van Groenigen of Northern Arizona University and colleagues analysed results from 53 different studies of soil carbon measurements in forests, grasslands and farmers’ fields around the world to see how CO2 affects plant growth, soil activity and soil carbon.

    They found that extra carbon dioxide in the #atmosphere meant more input into the soil – nearly 20% more – but it also meant more turnover, up by more than 16%.

    So if more went in, more was released, because the teeming microscopic fauna that inhabit the soil, recycle nutrients and redistribute plant nourishment also became more active.

    #climat #sol