Carbon dioxide in Earth's atmosphere Atmospheric O levels are decreasing in Earth's atmosphere as it reacts with the carbon in fossil fuels to form . Burning fossil fuels such as coal, petroleum, and natural gas is the leading cause of increased anthropogenic ; deforestation is the second major cause. In 2010, 9.14 gigatonnes of carbon (GtC, equivalent to 33.5 gigatonnes of or about 4.3 ppm in Earth's atmosphere) were released from fossil fuels and cement production worldwide, compared to 6.15 GtC in 1990. In addition, land use change contributed 0.87 GtC in 2010, compared to 1.45 GtC in 1990. In 1997, human-caused Indonesian peat fires
Carbon dioxide sensor measurement principle. Most CO₂ sensors are fully calibrated prior to shipping from the factory. Over time, the zero point of the sensor needs to be calibrated to maintain the long term stability of the sensor. Carbon dioxide sensor A carbon dioxide sensor or CO sensor is an instrument for the measurement of carbon dioxide gas. The most common principles for CO sensors are infrared gas sensors (NDIR) and chemical gas sensors. Measuring carbon dioxide is important in monitoring indoor air quality, the function of the lungs in the form of a capnograph device, and many industrial processes. NDIR sensors are