Around 2.3 billion people globally rely on biomass for cooking, contributing to severe health, environmental, and climate challenges, with household air pollution responsible for over 4 million deaths each year. This widespread dependence underscores the urgent need for accurate measurement of biomass consumption and associated emissions. The primary objective of this study is to enhance the understanding of household biomass energy use by quantifying the contributions of woody biomass and crop residues, examining seasonal consumption patterns, and estimating the resultant CO₂e emissions. The study’s novelty lies in its application of a digital, sensor-based system to continuously and accurately monitor biomass consumption across 420 households in Eastern Rwanda, conducted over three agricultural seasons. This approach generates high-resolution, region-specific data on the utilization of firewood, crop residues, and charcoal, while directly linking consumption patterns to CO₂e emissions. The findings indicate that firewood accounts for 86% of the total biomass used for cooking, followed by crop residues at 13% and charcoal at 0.8%. The estimated daily household consumption amounts to 3.1 kg of firewood, 0.47 kg of crop residues, and 0.03 kg of charcoal. The relatively high amount of crop residue suggests a chronic shortage of firewood, despite the intensive tree-planting campaigns. Firewood consumption remained stable during season A (short rainy) and season B (rainy), with a slight decrease in season C (dry). Crop residues decreased steadily from Season A to B, and further to C. The estimated annual CO2e emission from biomass combustion is 1.32 tons per household and 0.48 tons per capita. Digital methods provide precise, time-resolved data on fuel types and consumption, offering valuable insights for energy planning and carbon financing. Future research should integrate PM₂.₅ emissions to better assess health impacts and determine the sustainable balance between using crop residues as fuel and returning them to the soil.
Tag: carbon dioxide
Antibiotic residues in cattle manure increase greenhouse gas emissions during solid storage in Kenya
The increasing use of antibiotics in livestock farming raises concerns about environmental impacts. This study examined the effects of three commonly used veterinary antibiotics – Tylosin, Enrofloxacin, and Oxytetracycline – on manure greenhouse gas (GHG) emissions and fertilizer quality during solid manure storage. Aliquots of fresh cattle manure (10 kg) were either spiked with high or low concentrations of each antibiotic, or left untreated as Control, then incubated in open buckets for 110 days to simulate manure heaping. Emissions of CO2, CH4, and N2O were measured using a static chamber with a laser spectrometer. Tylosin (High and Low) treatments and High-dose Enrofloxacin significantly increased manure N2O emissions (2.1 ± 0.2 to 2.5 ± 0.4 %), exceeding the IPCC default values of 1 % manure-N. All antibiotic treatments increased CH4 emission factors (6.4 ± 0.7 to 14.2 ± 1.1 g CH4 kg−1 VS) compared to the Control (2.2 ± 0.5 g CH4 kg−1 VS) and the IPCC default value (4.44 g CH4 kg−1 VS). Overall, antibiotic residues increased the global warming potential (GWP) of stored solid manure by 218 % compared to the Control. Despite the slightly greater nitrogen losses from increased N2O emissions, the final fertilizer quality of the manure remained unaffected by the antibiotic treatments. Besides health concerns related to antimicrobial resistance, our findings on environmental impacts call for a One Health approach to promote sustainable antibiotic use in livestock production.
How does nitrogen application impact soil respiration and CH4 emissions? An experiment in an oil palm plantation on tropical peat
Oil palm cultivation on peatlands causes severe environmental damage, yet its greenhouse gas (GHG) footprint and underlying biogeochemical drivers remain poorly quantified. This study assessed how nitrogen fertilizer application impacts soil respiration and CH4 emissions across spatio-temporal scales in a fertilization trial with three application rates: 0 (N0), 154.5 (N1) and 309 (N2) kg N ha−1 yr−1. Fluxes and environmental variables were monitored monthly over a year and daily for a month after two fertilizations. Measurements were taken close to palms (CP), where fertilizer was applied, and farther from palm (FP). Soil respiration (Mg CO2-C ha−1 yr−1) was high compared to the literature, with N0 and N2 (27.3 ± 2.8 and 28.5 ± 3.0) exceeding N1 (18.8 ± 2.5). Fertilization triggered short-lived respiration increases, without affecting annual rates. Treatment and spatial differences (FP > CP) aligned with soil temperature and soil N2O emission patterns, suggesting links to peat mineralization. CH4 emissions (kg CH4-C ha−1 yr−1) were greater in N0 (3.9±1.5) compared to N1 (0.7 ± 0.6) and N2 (1.0 ± 1.3), inversely mirroring soil nitrate distribution under unfertilized conditions. A transient fertilizer effect occurred, without affecting annual rates. Our findings highlight strong interactions between soil respiration, CH4 emissions and N cycling in drained tropical peatlands, warranting further investigation to constrain GHG process-based modelling.
GHG emissions from recent peat forest disturbances: A driver-specific analysis across Indonesia, Peru, and DRC
Consistent data on tropical peat forest disturbances and associated greenhouse gas (GHG) emissions remain limited. We quantified and compared driver-specific GHG emissions from aboveground biomass (AGB) loss, peat decomposition and fire from peat forest disturbances in Indonesia, Peru, and Democratic Republic of Congo (DRC) over 2020-2021. Direct drivers were identified through visual interpretation of Planet (4.77 m) and Sentinel-2A (10 m) imagery for 1000 randomly sampled disturbance events per country. We estimated CO2 emissions from AGB loss using pre-disturbance data from the Climate Change Initiative Biomass product. Emissions (CO2, CH4 and N2O) from peat decomposition were calculated using driver-specific emission factors. We computed emissions from fire applying refined values for prescribed peat fires. Large-scale agriculture was the primary driver of emissions in Indonesia (48%), followed by smallholder agriculture (26%), and grassland (10%). Conversely, smallholder agriculture was the dominant driver of emissions in Peru (59%) and DRC (94%). Logging contributed to emissions across all countries, while mining, road development, and river meandering were relevant mainly in Indonesia and Peru; windstorms played a minor role in Peru. Fire accounted for half of emissions and was predominantly linked to agriculture (80% in Indonesia, 75% in Peru, and 95% in DRC). Overall, CO2 was the dominant GHG (72%), followed by CH4 (20%) and N2O (8%). Across countries, combined emissions from AGB loss, peat decomposition and fire in the disturbance year (2020) exceeded post-disturbance peat decomposition emissions in 2021 by 19-20 times. Nevertheless, cumulative peat decomposition over two decades will eventually reach the massive emissions released from all sources in the disturbance year. Our analysis provides the first systematic cross-country comparison of driver-specific GHG emissions in tropical peat forests, underscoring the major role of fire associated with agricultural expansion and the long-term importance of post-disturbance peat decomposition. These findings offer key insights to inform (inter) national emission reduction policies and strengthen reporting of peat forest emissions under frameworks such as the Paris Agreement.
Modeling vegetation carbon stock and soil greenhouse gas emission dynamics in undrained degraded peat swamp forests of Indonesia and Peru
Data on vegetation carbon storage and soil greenhouse gas (GHG) dynamics in degraded undrained peatlands, and their recovery timeframes, are limited. Additionally, despite their important extent across the tropics, these systems remain unconsidered by the Intergovernmental Panel on Climate Change guidelines for GHG inventories. We modified the existing DeNitrification DeComposition model to simulate undegraded and degraded undrained peat swamp forests in Indonesia and Peru. We simulated partial clearing for agroforestry and burning in Indonesia, and in Peru selective timber harvesting and Mauritia flexuosa palm cutting for fruit harvest. Based on model results, we derived peat onsite CO2, N2O, and CH4 emission factors (EF), assessed timeframes for recovery of vegetation C stocks and peat GHG emissions, and investigated relationships among peat GHG fluxes and biophysical controls. Vegetation carbon stocks recovered 40 years after modeled disturbance in Indonesia, and 80 years post-disturbance in Peru. Simulated degradation increased the peat onsite CO2 EF during the first decade post-disturbance by 557% and 121% in Indonesia and Peru, respectively, with recovery by the second decade post-disturbance at both locations. Degradation also induced an increase in soil N2O emissions in Indonesia (344%) and Peru (323%), with elevations persisting for four decades. As in field observations, simulated disturbances tended to raise CH4 emissions in Indonesia and lower them in Peru, but not substantially. Temporal variations in modeled peat onsite CO2 and N2O EF were linked to degradation-driven changes in soil C:N ratio, and for peat CH4 fluxes to water table and soil moisture dynamics unrelated to disturbance. Our results suggest elevation of peat GHG emissions in these forests up to four decades after anthropogenic disturbances that need accounting in national GHG inventories.
Beyond Reducing Deforestation: Impacts of a REDD+ Project on Household Livelihoods
Understanding why forest conservation initiatives succeed is essential to designing cost-effective programs. In this study, we investigate the impacts of a REDD+ project on both environmental and livelihood outcomes in the Brazilian Transamazon region, an area with historically high deforestation rates. Using counterfactual impact evaluation methods applied to survey and remote-sensing data, we assess the impact of the project over 2013–2019, from its first year until two years after its end. Based on a theory of change, we focus on land use and socioeconomic outcomes affected by the initiative. Our findings reveal specific impact mechanisms: forest conservation occurred primarily through reducing pasture expansion, while cattle production was maintained through intensification (increased stocking rates). Additionally, the project led to significantly higher agrobiodiversity among participating farms and promoted alternative livelihoods that generated greater revenue while using less land. These results suggest that conservation programs that combine conditional payments with technical assistance and support for adopting low-impact activities can effectively reduce deforestation in the short term and induce lasting changes in production systems, with positive effects persisting even after program completion.
Physiology of A. nilotica and C. africana intercropped in Melkassa semi-arid region of Ethiopia
Enhancing crop productivity requires climate-smart agroforestry systems to reduce adverse weather conditions and to enhance soil nutrient fertility in the semi-arid regions. This research was carried out at the Melkassa long-term experimental site between July 2018 and February 2019. The main objective of this research was to investigate tree water use, gas exchange, and nutrient content of A. nilotica and C. africana litter to evaluate the impact on the accompanying crops. Three trees were selected from each tree species. There was a temporal variation in carbon dioxide assimilation rate between C. africana and A. nilotica. A strong correlation coefficient was observed between WUE and the carbon dioxide assimilation rate of both trees compared to other physiological measurements. Leaf water potential and sap volume of both trees declined during the dry periods. Both leaf nitrogen and phosphorous contents recorded in A. nilotica were higher compared to C. africana. However, the SPAD value measured in C. africana was significantly higher during the onset of the main rainy seasons compared to A. nilotica. The differences in WUE and carbon flux of trees are mainly dependent on environmental factors. A. nilotica demonstrated higher nitrogen contribution and more stable WUE under drought conditions, suggesting its suitability for semi-arid intercropping systems. Thus, integration of trees known for high water use efficiency and quality nutrient deposition has paramount importance to enhance crop productivity in semi-arid environments where soil fertility is slow and intermittent rainfall is most prevalent.
3.4. PEATLANDS (in Chapter 3: Soil)
Peatlands are among the most concentrated terrestrial carbon stores, containing about 644 GtC, or 21% of global soil organic carbon (SOC). This is nearly double the carbon stored in all forest biomass worldwide. Despite covering only 3% of Earth’s land surface, peatlands are critical carbon reservoirs, mainly located in boreal and temperate regions, with smaller areas in the tropics. When drained for agriculture or other land uses, peatlands release large amounts of CO₂ and N₂O due to microbial decomposition. Current degraded and cultivated peatlands are projected to cumulatively emit 80.8 Gt of carbon and 2.3 Gt of nitrogen over the coming centuries, equivalent to contemporary annual emissions of 1.91 (0.31–3.38) GtCO₂e. Protecting peatlands is therefore vital for climate mitigation.
Réduire les émissions de CO2 en protégeant les forêts : l’ambition du mécanisme REDD+
La REDD+ (Réduction des Emissions dues à la Déforestation et à la Dégradation des forêts) s’est installée dans l’architecture des négociations climatiques comme un des principaux outils pour réduire les émissions de gaz à effets de serre (GES) liées aux forêts. Très vite, il est apparu nécessaire de tenir compte d’autres secteurs dans le mécanisme, notamment l’agriculture. Comment s’est déroulée sa mise en place ? Quels sont les acteurs impliqués ? Quelle est la prise en compte effective de l’agriculture dans le processus ? Tour d’horizon des enjeux et illustration en République Démocratique du Congo.
Reducing emissions from deforestation and forest degradation (REDD) in Indonesia: options and challenges for fair and efficient payment distribution mechanisms
The objective of REDD payment distribution mechanisms is to support policies and measures that reduce deforestation and degradation through transfer of revenues from international REDD funds or carbon markets to (or within) national levels. This may provide benefits of three types: a) shared responsibility for reducing a major driver of global climate change, b) financial payments and co-investment that exceed the economic opportunities foregone from decisions to maintain carbon stocks, and c) co-benefits through the other environmental service functions that well-maintained forests can provide. Given its track record of high emissions from land use and land use change of an estimated 2.5 Gt CO2e year-1, Indonesia provides a huge opportunity as well as serious challenge to reduce emissions. We report here on a series of stakeholder consultations and focus group discussions to identify options and challenges. To ensure demonstrable results on emission reduction, REDD mechanisms must be effective in targeting the wide range of agents involved in deforestation and degradation, learning lessons from past and ongoing conservation efforts that have apparently failed. They must reward good performance and incentivize improved performance compared to reference scenarios, and adequately compensate agents that suffer losses from changed practices. International payments are likely to be performance based, both in terms of emission reduction at national scale and the environmental and social impacts of the system, meaning that accountability, transparency, risk management, adequate benefits transfer and administration mechanisms will be essential for attracting investment. Indonesia will be effectively competing for attention and REDD funds with other countries with currently high pemissions and/or large forest areas. A strong international ‘bargaining position’ requires that internal conflicts and strategic positioning be overcome