We compiled, measured and simulated estimates of NPP and NBP for Amazonian tropical, European temperate, and Siberian Boreal forests from intensive stand-scale field studies, extensive forest biomass ...inventories, regional atmospheric inversions, and global ecosystem models. We analysed the random and systematic sources of uncertainties pertaining to each approach when comparing their results, and showed that estimates of NPP from different data streams are robustly comparable within their errors. Although NPP increases by a factor of four between Siberia and the Amazon, NBP is larger in Europe than elsewhere, demonstrating that carbon sequestration does not correlate with NPP. We analysed the NPP:NBP ratios in terms of the role of CO2 fertilization. Our results show that the tropical forest NBP carbon sink can be entirely explained by a CO2-induced enhancement of NPP, whereas such a mechanism can only account for 10% of the European sink and up to 50% of Siberian sink. Europe and Siberia are the two regions where factors other than CO, are likely to be dominant in controlling the sequestration of carbon by forest ecosystems, such as management practice, climate, nitrogen deposition, and variation in disturbance regimes.
As the COVID-19 virus spread over the world, governments restricted mobility to slow transmission. Public health measures had different intensities across European countries but all had significant ...impact on peoples daily lives and economic activities, causing a drop of CO2 emissions of about 10% for the whole year 2020. Here, we analyze changes in natural gas use in the industry and built environment sectors during the first half of year 2020 with daily gas flows data from pipeline and storage facilities in Europe. We find that reductions of industrial gas use reflect decreases in industrial production across most countries. Surprisingly, natural gas use in buildings also decreased despite most people being confined at home and cold spells in March 2020. Those reductions that we attribute to the impacts of COVID-19 remain of comparable magnitude to previous variations induced by cold or warm climate anomalies in the cold season. We conclude that climate variations played a larger role than COVID-19 induced stay-home orders in natural gas consumption across Europe.
Ten years of Greenhouse gas Observing SATellite (GOSAT) observation achieves valuable retrievals for top-down methane (CH 4 ) emissions estimates especially in regions lacking ground-based ...observations. This paper presents the long-term 2010-2017 trend in CH 4 emissions in the Middle East countries. We use a global 0.1^{\circ}\times 0.1^{\circ} high-resolution inverse model, NIES-TM-FLEXPART-VAR (NTFVAR) with GOSAT retrievals and surface observations. Prior fluxes contain adjusted EDGAR v4.3.2 scaled to match the country totals by national reports to the United Nations Framework Convention on Climate Change (UNFCCC), augmented by biomass burning emissions from Global Fire Assimilation System (GFASv1.2) and wetlands emissions from Vegetation Integrative Simulator for Trace Gases (VISIT) model. The result shows the total annual CH 4 emission of 23.54 Tg CH 4 yr −1 in the Middle East with more than 95% emissions from anthropogenic sources, and there is no statistically significant emissions trend from 2010 to 2017.
The main objectives of this thesis were to assess soil CO 2 efflux rates in ‘De Inslag’, a mixed forest in Brasschaat (Belgian Campine region) and to gain insight in the below-ground responses of ...trees and forests to the increasing levels of atmospheric CO2. Even within homogeneous patches, soil CO2 efflux is characterized by a large spatial variability. Whereas the differences between different vegetation types were primarily related to the differences in litter quality, we could not explain the within-vegetation type spatial variability. This was probably related to the fact that soil CO2 efflux is affected by a large number of biotic and abiotic factors. The effect of one of these factors on soil CO2 efflux is therefore likely to be confounded by the effects of the other factors. In addition to the large spatial variability, soil CO2 efflux is also characterized by a large temporal variability. These were found to be related to soil temperature soil moisture. A basic empirical model was developed to simulate soil CO2 efflux from soil temperature and soil moisture. This model was used to estimate the mean annual (1997) soil CO2 efflux for the forest.
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