Dataset Information

Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO₂ signal.

ABSTRACT: Tropical ecosystems are large carbon stores that are vulnerable to climate change. The sparseness of ground-based measurements has precluded verification of these ecosystems being a net annual source (+ve) or sink (-ve) of atmospheric carbon. We show that two independent satellite data sets of atmospheric carbon dioxide (CO₂), interpreted using independent models, are consistent with the land tropics being a net annual carbon emission of [Formula: see text] [Formula: see text] and [Formula: see text] petagrams (PgC) in 2015 and 2016, respectively. These pan-tropical estimates reflect unexpectedly large net emissions from tropical Africa of [Formula: see text] PgC in 2015 and [Formula: see text] PgC in 2016. The largest carbon uptake is over the Congo basin, and the two loci of carbon emissions are over western Ethiopia and western tropical Africa, where there are large soil organic carbon stores and where there has been substantial land use change. These signals are present in the space-borne CO₂ record from 2009 onwards.

SUBMITTER: Palmer PI

PROVIDER: S-EPMC6692308 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO<sub>2</sub> signal.

Palmer Paul I PI Feng Liang L Baker David D Chevallier Frédéric F Bösch Hartmut H Somkuti Peter P

Nature communications 20190813 1

Tropical ecosystems are large carbon stores that are vulnerable to climate change. The sparseness of ground-based measurements has precluded verification of these ecosystems being a net annual source (+ve) or sink (-ve) of atmospheric carbon. We show that two independent satellite data sets of atmospheric carbon dioxide (CO<sub>2</sub>), interpreted using independent models, are consistent with the land tropics being a net annual carbon emission of [Formula: see text] [Formula: see text] and [Fo ...[more]

PMID: 31409792

Similar Datasets

Project description:ConspectusThe atmosphere-biosphere exchange of nitrogen oxides plays a key role in determining the composition of reactive nitrogen in terrestrial vegetated environments. The emission of nitric oxide (NO) from soils is an important atmospheric source of reactive nitrogen. NO is rapidly interconverted with NO2, making up the chemical family NOx (NOx ≡ NO2 + NO). NOx further reacts with the oxidation products of volatile organic compounds (VOCs) to form the functionalized nitrogen oxide groups acyl peroxynitrates (APNs = R(O)O2NO2) and alkyl nitrates (ANs = RONO2). Both canopy-level field measurements and laboratory studies suggest that the absorption of nitrogen dioxide NO2 and APNs by vegetation is a significant sink of atmospheric NOx, removing a large fraction of global soil-emitted NOx and providing key control on the amounts and lifetimes of NOx and reactive nitrogen in the atmosphere. Nitrogen oxides influence the production of surface O3 and secondary aerosols. The balance of the emission and uptake of nitrogen oxides thus provides a mechanism for the regulation of regional air quality. The biosphere, via this biogeochemical cycling of nitrogen oxides, is becoming an increasingly important determining factor for airborne pollutants as much of the world continues to reduce the amount of combustion-related nitrogen oxide emissions. Understanding the function of the biosphere as a source and sink of reactive nitrogen is therefore ever more critical in evaluating the effects of future and current emissions of nitrogen oxides on human and ecosystem health.Laboratory measurements of the foliar deposition of NO2 and other reactive nitrogen species suggest that there is a substantial diversity of uptake rates under varying environmental conditions and for different species of vegetation that is not currently reflected in the widely utilized chemical transport models. Our branch chamber measurements on a wide variety of North American tree species highlight the variability in the rates of both photosynthesis and nitrogen oxide deposition among several different nitrogen oxide compounds. Box-modeling and satellite measurement approaches demonstrate how disparities between our understanding of nitrogen oxide foliar exchange in the laboratory and what is represented in models can lead to misrepresentations of the net ecosystem exchange of nitrogen. This has important implications for assumptions of in-canopy chemistry, soil emissions of NO, canopy reductions of NOx, lifetimes of trace gases, and the impact of the biosphere on air quality.

Dataset Information

Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO₂ signal.

Publications

Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO<sub>2</sub> signal.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO2 signal.

Publications

Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO<sub>2</sub> signal.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO₂ signal.