Elevated carbon dioxide (CO2) and temperature vis-a-vis carbon sequestration potential of global terrestrial ecosystem

Abstract

Industrialization across the world during the twentieth century enhanced global economic growth rate in quantum speed, but the global greenhouse gases (GHGs) level in the atmosphere also augmented in the manifold along with the economic growth. The elevated level of GHGs particularly CO2 due to burning of fossil fuels and agricultural and industrial process increased the atmospheric temperature. The global mean surface temperature has increased by about 0.74 °C over the last 100 years. The Intergovernmental Panel on Climate Change (IPCC) projected that it will rise further to 1.4-6.4 °C units by the end of the twenty-first century. The consequences of global warming is felt everywhere, viz., poor and uncertainty of rainfall, prolonged dry spell, more incidence of insect and pest, reduction in soil carbon, more water stress to crop plants, reduction in crop productivity, etc. The rising atmospheric CO2 affected the plant physiological processes and soil microorganism activities and biochemical pathway of plant nutrients as well as carbon (C) source-sink relationships of terrestrial ecosystems. Hence mitigation and sequestration of C as stable pool in soil is the need of hour to counter the increasing CO2 in the atmosphere. Soil is a major store of C, containing three times as much as C in the atmosphere and five times as much as forests. But a minor variation in such big C pool in terrestrial ecosystems may have a significant effect on the C flux. Due to environmental complexities, it is difficult to quantify soil C changes. However, researchers across the world are trying to estimate the soil carbon dynamics under different land-use and management systems to bridge the gap in the carbon sequestration potential. Also use of available agronomic and management options can be effectively utilized to combat the adverse effect of elevated CO2 and temperature; thereby, crop productivity and sustainability of the terrestrial ecosystem are maintained for a long run.