According to the quantities of plant and animal products placed on the world market in 2022, agriculture and forestry captured 20.1 ± 1.5 billion tonnes (Gt or Pg) of CO2, with a weighted mean duration of the cor...According to the quantities of plant and animal products placed on the world market in 2022, agriculture and forestry captured 20.1 ± 1.5 billion tonnes (Gt or Pg) of CO2, with a weighted mean duration of the corresponding storage of 10.9 ± 3.3 years. These figures are supplemented here by the unharvested above-ground and below-ground parts of plants that are left in place and increase the soil organic carbon pool. This brings the capture by cultivated whole plants to 41.0 ± 0.6 GtCO2, and the storage duration weighted mean to 26.3 ± 2.0 years in 2022. This was the largest global contribution to the reduction of atmospheric CO2 by amplitude and duration, which bio-remediated the global anthropogenic emissions totally, cancelling their influence on climate. The enrichment of the atmosphere with CO2 comes probably from the ocean, which could be a source and not a sink. Complementary approaches, freed from doctrinal preconceptions, should make it possible to clarify further the compensations of CO2 emissions by plants and their environmental consequences.展开更多
Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and com...Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and compared them to the glacial ACC cycles as reported from ice cores archives. In 2020, the overall continental absorption (AW) was 8.0 giga tonnes of carbon per year (GtC/y). Emissions into the atmosphere (EW) resulting from mineral degradation by respiration and combustion of biomass and fossil hydrocarbons were 14.7 GtC/y, an increase of 2.4% per year since 1970. The continental surplus balance (-AW+EW) of 6.7 GtC/y was shared between the atmosphere, which received 5.1 GtC/y (GATM), and the ocean which absorbed 1.6 GtC/y. This ocean contribution (OC) corresponded to 17% of the 9.2 GtC/y emissions by combustion of fossil hydrocarbons (EFOS). Analysis of the ACC oscillations during 2020 in the northern hemisphere showed that the ocean absorbed 11.1 GtC during the warm season and outgassed 9.5 GtC during the cold season. Assuming proportionality to world population, the ACC, 414 parts per million (ppm) in 2021, would reach 584 ppm in 2080, still growing at a rate of 0.6% per year. The gain of atmospheric CO<sub>2</sub> (GATM) and its absorption by the ocean (OC) were expected to peak at 7.0 and 2.2 GtC/y, respectively, in 2080. This increase in the availability of atmospheric CO<sub>2</sub> resulted in improved yields of agriculture which more than compensated for the reduction by half of food-producing areas per capita from 1970.展开更多
文摘According to the quantities of plant and animal products placed on the world market in 2022, agriculture and forestry captured 20.1 ± 1.5 billion tonnes (Gt or Pg) of CO2, with a weighted mean duration of the corresponding storage of 10.9 ± 3.3 years. These figures are supplemented here by the unharvested above-ground and below-ground parts of plants that are left in place and increase the soil organic carbon pool. This brings the capture by cultivated whole plants to 41.0 ± 0.6 GtCO2, and the storage duration weighted mean to 26.3 ± 2.0 years in 2022. This was the largest global contribution to the reduction of atmospheric CO2 by amplitude and duration, which bio-remediated the global anthropogenic emissions totally, cancelling their influence on climate. The enrichment of the atmosphere with CO2 comes probably from the ocean, which could be a source and not a sink. Complementary approaches, freed from doctrinal preconceptions, should make it possible to clarify further the compensations of CO2 emissions by plants and their environmental consequences.
文摘Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and compared them to the glacial ACC cycles as reported from ice cores archives. In 2020, the overall continental absorption (AW) was 8.0 giga tonnes of carbon per year (GtC/y). Emissions into the atmosphere (EW) resulting from mineral degradation by respiration and combustion of biomass and fossil hydrocarbons were 14.7 GtC/y, an increase of 2.4% per year since 1970. The continental surplus balance (-AW+EW) of 6.7 GtC/y was shared between the atmosphere, which received 5.1 GtC/y (GATM), and the ocean which absorbed 1.6 GtC/y. This ocean contribution (OC) corresponded to 17% of the 9.2 GtC/y emissions by combustion of fossil hydrocarbons (EFOS). Analysis of the ACC oscillations during 2020 in the northern hemisphere showed that the ocean absorbed 11.1 GtC during the warm season and outgassed 9.5 GtC during the cold season. Assuming proportionality to world population, the ACC, 414 parts per million (ppm) in 2021, would reach 584 ppm in 2080, still growing at a rate of 0.6% per year. The gain of atmospheric CO<sub>2</sub> (GATM) and its absorption by the ocean (OC) were expected to peak at 7.0 and 2.2 GtC/y, respectively, in 2080. This increase in the availability of atmospheric CO<sub>2</sub> resulted in improved yields of agriculture which more than compensated for the reduction by half of food-producing areas per capita from 1970.
