The Paris Agreement on Climate sets the international objective to keep climate warming well below two degrees, and "…to reach global peaking of greenhouse gas emissions as soon as possible … and to undertake rapid reductions thereafter in accordance with best available science...to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century".
This extraordinary challenge requires dramatic improvements of current scientific capabilities to construct comprehensive GHG budgets with all natural and anthropogenic sources and sinks that drive changes in atmospheric concentrations, and track changes over time.
Scientific Objectives of RECCAP2:
- To establish the GHG budgets of large regions covering the entire globe at the scale of continents (or large countries) and large ocean basins, including their component fluxes (2010-2019 or later).
- To produce new synthesis of global land, ocean and their interface GHG fluxes.
Policy-relevant objectives of RECCAP2:
- To contribute to the global stocktake and tracking towards net zero emissions of anthropogenic and natural GHG sources and sinks.
- To quantify and further constrain anthropogenic greenhouse gas emissions.
- To develop robust observation-based estimates of changes in carbon storage and greenhouse gas emissions and sinks by the oceans and terrestrial ecosystems.
- To improve our knowledge of the processes driving changes in GHG sources and sinks.
- To gain science-based evidence of the response of marine and terrestrial regional GHG budgets to climate change and direct anthropogenic drivers.
What is new in RECCAP2 compared to RECCAP1?
- GHG budgets to C/CO2, CH4 and N2O (RECCAP1 only CO2).
- Inclusion of coastal ecosystems (blue carbon).
- Explore plausible evolution of GHG budgets under difference climate scenarios based on CMIP6 and other modeling efforts.
- Inclusion of special topics: Land-to-Ocean-Aquatic-Continuum, Permafrost, Polar regions.
- Uptake of new global and regional GHG flux/stock products available, both observational and remote sensing (biomass, fire, freshwater bodies, wetlands, GPP, NEE and others.
- Improved and better constrained models (eg, land surface and ocean N2O modeling).
- Highlight nature-based climate solutions.
How RECCAP2 is organized:
- RECCAP2 is a bottom-up effort by the global research community and driven by the Global Carbon Project with partner groups.
- Builds from existing global and regional projects, and voluntary contributions.
- Timeframe. Community consultation and preparations: 2016-2020; Assessment: 2020-2022 as a contribution to the Global Stocktake of the Paris Agreement./li>
To address these objectives, RECCAP2 will design and perform a set of global syntheses and regional GHG budgets of all lands and oceans, and explore mechanisms by which to deliver regular updates of these regional assessments based on scientific evidence, considering uncertainties, understanding of drivers, and retrospective analysis of recent trends.