Current climate models suggest that trees will continue to remove manmade greenhouse gas emissions from the atmosphere, making it possible to stay within the targets set by the Paris Agreement.
Current climate models suggest that trees will continue to remove manmade greenhouse gas emissions from the atmosphere, making it possible to stay within the targets set by the Paris Agreement. A study by an international team including researchers from IIASA however indicates that this uptake capacity could be strongly limited by soil phosphorus availability.
Trees absorb CO2 through their leaves and turn greenhouse gases into oxygen and biomass. According to estimates by the International Panel on Climate Change (IPCC), the Amazon rainforest in particular, absorbs around a quarter of the CO2 that is released each year due to fossil fuel combustion. Today’s global climate models assume that this capacity will be maintained in the future due to the so-called CO2 fertilization effect, which proposes that rising levels of CO2 promote vegetation growth by accelerating the rate of photosynthesis that plants use to produce biomass. Deforestation, agricultural expansion, and rising temperatures are however pushing the storage capacity of the Amazon forest to its limit, and according to researchers, it is unclear how long it will remain a carbon sink. An international team including researchers from IIASA explored this question using data from the first tropical Free Air CO2 Enrichment (FACE) experiment conducted in the middle of the Amazon rainforest.
The AmazonFACE project includes a unique experimental technical set-up at a study site located approximately 70 kilometers north of Manaus, Brazil, in which the ambient CO2 concentration is artificially increased, thus enabling a realistic investigation of how future CO2 concentrations will affect the ecosystem. Researchers monitor how the trees are growing and the leaves are developing aboveground, while also tracking root growth and what is happening in the soil below ground. In their paper published in Nature Geoscience, the authors applied a number of ecosystem models to investigate the extent to which soil nutrient supply might limit the production of biomass in tropical forests.
Read more at International Institute for Applied Systems Analysis
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