Most sources of emissions are natural, and are balanced to various degrees by similar sinks. For example, the decay of organic material in forests, grasslands, and other land vegetation - including the infrequent activity of forest fires - results in the release of about 400 gigatonnes of (containing 120 billion tonnes carbon) every year, while uptake by new growth on land nearly counteracts these releases. Although much in the early atmosphere of the young Earth was produced by volcanic activity, modern volcanic activity releases only 130 to 230 megatonnes of each year. This small natural geologic source is also balanced by natural sinks, in the form of chemical and biological processes which remove from the atmosphere. By contrast, as of year 2019 the extraction and burning of geologic fossil carbon by humans releases over 30 gigatonnes of (9 billion tonnes carbon) each year. This larger disruption to the natural balance is responsible for recent growth in the atmospheric concentration.