Plant photosynthesis was stable for hundreds of years before the industrial revolution, but then grew rapidly in the 20th century
The researchers discovered the record of global photosynthesis by analyzing Antarctic snow data captured by NOAA. Gases trapped in different layers of Antarctic snow allow scientists to study global atmospheres of the past. This studies focused on a gas stored in the ice that provides a record of the Earth's plant growth.
Virtually all life on our planet depends on photosynthesis. The study found that the observation-based COS record is most consistent with simulations of climate and the carbon cycle that assume large GPP growth during the twentieth century (31% increase).
The scientists analyzed a gas called carbonyl sulfide (COS). It’s a cousin of CO2. Plants remove COS from the air through a process that is related to the plant uptake of CO2. While photosynthesis is closely related to the atmospheric COS level, other processes in oceans, ecosystems, and industry, can change the COS level also. To account for all of these processes, the inter-disciplinary team of scientists developed an Earth system model of COS sources and sinks. Although this COS analysis does not directly constrain models of future GPP growth, it does provide a global-scale benchmark for historical carbon-cycle simulations.
Contacts (BER PM)
Elliott Campbell, UC Merced
DOE / TES DE-SC0011999
J.E. Campbell et al., “Large historical growth in global terrestrial gross primary production.” Nature (2017). doi:10.1038/nature22030.
DOE Terrestrial Ecosystem Science DE-SC0011999