The link between anthropogenic greenhouse gas emissions, especially CO2, and global warming has been unambiguously established by the IPCC’s 4th Assessment Report but still a considerable gap exists in our knowledge of the global carbon cycle, especially in the estimates of land and ocean sources and sinks of CO2. The need to reduce this uncertainty, especially in regional and country-wise emissions and uptake is paramount for reliably estimating impacts of future emission trends as well as retain knowledge based initiatives in negotiating international treaties for limiting CO2 emissions.
Terrestrial and oceanic carbon cycles are quite difficult to quantify because of the complexity of the processes involved – photosynthesis, respiration, plant growth and decay, ecosystem dynamics, chemical kinetics and transport, considerable headway can be made through a judicious mix of observations and modelling. It would therefore be prudent for India to plan for rapid progress in this field during the next plan.
The estimation of robust GHG fluxes from India and surrounding seas involves a synthesis of high quality atmospheric GHG measurements and inverse modelling to infer fluxes. The accuracy demand of the measurement as established by WMO/GAW is of the order of 0.01 ppm for CO2 and 1 ppb for CH4 as we try to extract very small interannually-varying signals in the background measurements which are representative of reasonably large areas. WMO/GAW has established procedures for participating labs to ensure that these standards are maintained and India must participate in this activity to establish credibility of its measurement programme.
We estimate that a network of ~20 GHG measurement stations, both flask and in-situ, would be necessary to obtain robust regional estimates of GHG fluxes from India and its adjacent seas. As these stations are expensive to set-up and maintain, an analytically designed network strategy is required to gain maximum trade-of in the minimization of aposteriori errors. A final refinement will be based on a synthesis of back trajectory analysis and network design.
The complexity of inversion will keep pace with the density of measurements. From a coarse (spatial and temporal) resolution methodology based on synthesis inversion, we should progress to full scale 4D-variational assimilation which will have the ability to track the complete fate of CO2 emitted from anywhere on the globe.
The refinement of biogeochemical models (carbon, nitrogen, silica, phosphorous, iron cycles) in the various earth-system components (atmosphere, land and ocean) should be a major focus of activity in the XII Plan. This will involve a close synergy between different observation programmes (biological and chemical oceanographic cruises, remote sensing of marine and terrestrial productivity) and development of terrestrial and marine ecosystem models. These will finally be integrated into Earth System Models (ESM) which will have the ability to predict future climate impacts which may include ocean acidification, loss of biodiversity and productivity. The ESMs will also assist us in evaluating strategies for climate-change mitigation such as ocean fertilisation and other futuristic schemes.
A comprehensive knowledge of the carbon cycle – sources, sinks, and biogeochemical interactions.
A state-of-the-art GHG measurement network capable of an accuracy of 0.01 ppm CO2 and 1 ppb CH4.
An analysis centre with state of the art GC and Mass specs which can deliver above accuracy. The centre will ensure adherence to WMO standards.
(Rs. In crores)
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Last Updated On 04/06/2015 - 16:39