Aboveground forest biomass varies across continents, ecological zones and successional stages: refined IPCC default values for tropical and subtropical forests

For monitoring and reporting forest carbon stocks and fluxes, many countries in the tropics and subtropics rely on default values of forest aboveground biomass (AGB) from the Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas (GHG) Inventories. Default IPCC forest AGB values originated from 2006, and are relatively crude estimates of average values per continent and ecological zone. The 2006 default values were based on limited plot data available at the time, methods for their derivation were not fully clear, and no distinction between successional stages was made. As part of the 2019 Refinement to the 2006 IPCC Guidelines for GHG Inventories, we updated the default AGB values for tropical and subtropical forests based on AGB data from >25,000 plots in natural forests and a global AGB map where no plot data were available. We calculated refined AGB default values per continent, ecological zone, and successional stage, and provided a measure of uncertainty. AGB in tropical and subtropical forests varies by an order of magnitude across continents, ecological zones, and successional stage. Our refined default values generally reflect the climatic gradients in the tropics, with more AGB in wetter areas. AGB is generally higher in old-growth than in secondary forests, and higher in older secondary (regrowth >20 years old and degraded/logged forests) than in young secondary forests (≤20 years old). While refined default values for tropical old-growth forest are largely similar to the previous 2006 default values, the new default values are 4.0 to 7.7-fold lower for young secondary forests. Thus, the refined values will strongly alter estimated carbon stocks and fluxes, and emphasize the critical importance of old-growth forest conservation. We provide a reproducible approach to facilitate future refinements and encourage targeted efforts to establish permanent plots in areas with data gaps.

The analysis of carbon footprint of the settlement activity in the village of Pedurungan District, Semarang City, Central Java Province

Some important sectors influenced the increase of greenhouse gases, such as waste, transportation, settlement, and agricultural sectors. This research aimed to analyze the amount of CO2 emissions, map the carbon footprint, and analyze tree capability in reducing CO2 in 12 villages in Pedurungan district, Semarang city, Central Java. The method used was based on IPCC Guidelines for National Greenhouse Gas Inventories 2006 and Ministry of Environment 2012 about the Implementation of National Greenhouse Gas Inventories Guidelines. The carbon footprint was mapped using ArcGIS software. The results showed that the energy sector produced 13.723,35 tons CO2 Eq, the transportation sector emitted 1.624,58 tons CO2 Eq, and the waste sector emitted 7.677,08 CO2 Eq. The carbon footprint map was presented in three classifications of carbon footprint: lower, middle, and upper, represented by green, yellow, and red colors. An effort to reduce the carbon footprint was planting 300 trees of ten species in the Pedurungan district.

GHG Emissions Assessment of Civil Construction Waste Disposal and Transportation Process in the Eastern Amazon

The urbanization process represented by an increased supply of housing and transport infrastructure has taken place at an accelerated rate in several regions of Brazil, especially in the metropolitan areas of the Brazilian Amazon. Despite the existence of environmental policies that guide the proper disposal of civil construction waste (CCW) in Brazil, the impacts of these policies are still negligible, pointing to the need to establish other metrics such as the measurement of greenhouse gas (GHG) emissions in CO2eq associated with civil construction waste. This work aims to evaluate, in the second-largest city in the Brazilian Amazon, the environmental impact generated by the transportation of CCW to disposal sites, having as indicators the volume of this waste and the CO2 emissions produced during a whole year. A literature review on life cycle carbon emissions assessment in building construction and CO2 emissions in transportation are provided to establish the background of the research methodology. Data collection was carried out by searching large generators of construction waste, the companies responsible for transporting construction waste, and the types of vehicles used. Calculation of GHG emissions from CCW transportation was based on the method described in the 2006 IPCC Guidelines. The study identified a volume of waste of around 1244 m3/month, with a generation of 40,440 kgCO2/year, only from small and large generators. Besides the damage identified in this study, there is also the dumping of CCW into urban streams in the city which is causing negative impacts on sanitation and drainage systems. The results point to the need to strengthen local policies to mitigate the impacts of the existing CCW to contribute to a more sustainable city.

Blue Carbon Soil Stock Development and Estimates Within Northern Florida Wetlands

Blue carbon habitats, such as mangroves and salt marshes, have been recognized as carbon burial hotspots; however, methods on measuring blue carbon stocks have varied and thus leave uncertainty in global blue carbon stock estimates. This study analyzes blue carbon stocks in northern Florida wetlands along the Atlantic and Gulf coasts. Carbon measurements within 1–3m length vibracores yield total core stocks of 9.9–21.5 kgC·m−2 and 7.7–10.9 kgC·m−2 for the Atlantic and Gulf coast cores, respectively. Following recent IPCC guidelines, blue carbon stock estimates in the top meter are 7.0 kgC·m−2–8.0 kgC·m−2 and 6.1 kgC·m−2–8.6 kgC·m−2 for the Atlantic and Gulf cores, respectively. Changes in stable isotopic (δ13C, C/N) and lignin biomarker (C/V) indices suggest both coastlines experienced salt marsh and mangrove transgressions into non-blue carbon habitats during the mid- to late-Holocene following relative sea-level rise. These transgressions impact carbon storage within the cores as the presence of carbon-poor soils, characteristic of non-blue carbon habitats, result in lower 1m carbon stocks in north Florida Gulf wetlands, and a deeper extent of carbon-rich soils, characteristic of blue carbon habitats, drive higher 1m and total carbon stocks in north Florida Atlantic wetlands. Future blue carbon research should assess carbon stocks down to bedrock when possible, as land-cover and/or climate change can impact different depths across localities. Ignoring carbon-rich soil below the top meter of soil may underestimate potential carbon emissions based on these changes.

Estimation of N2O Emissions from Agricultural Soils and Determination of Nitrogen Leakage

Leaching of nitrogen from the soil is a natural but unfavorable effect that generates N2O emissions. Exact quantification of nitrogen leakage is a challenging process. Intensive leakage occurs mainly when the soil is without vegetation and under specific climatic conditions. This paper aims to quantify the amount of nitrogen leakage from arable land and grassland, and to estimate N2O emissions in 2017. Estimating the country-specific fraction of leached nitrogen (FracLEACH) is important for the emission balance from this source. Emissions are underestimated when the fraction is low; on the contrary, a high fraction causes overestimation. The internationally recognized fraction is 30%, according to the 2006 Intergovernmental Panel on Climate Control (IPCC) Guidelines. This factor represents the fraction of nitrogen losses compared to total nitrogen inputs and sources. In this study, we analyzed the effects of climatic conditions on agricultural soils in Slovakia to evaluate the area of nitrogen loss through leaching.

Assessing Energy-Based CO2 Emission and Workers’ Health Risks at the Shipbreaking Industries in Bangladesh

The study represents the estimation of energy-based CO2 emission and the health risks of workers involved in the shipbreaking industries in Sitakunda, Bangladesh. To calculate the carbon emission (CE) from three shipbreaking activities, i.e., metal gas cutting (GC), diesel fuel (FU) and electricity consumption (EC), we used the Intergovernmental Panel on Climate Change (IPCC) guidelines and Environmental Protection Agency (EPA)’s Emission and Generation Resource Integrated Database (eGRID) emission factors. Moreover, the geographic weighted regression (GWR) model was applied to assess the contribution of influencing factors of CE throughout the sampling points. To assess the workers’ health condition and their perceptions on environmental degradation, a semi-structured questionnaire survey among 118 respondents were performed. The results showed that total CO2 emissions from GC were 0.12 megatons (MT), 11.43 MT, and 41.39 MT for daily, monthly, and yearly respectively, and the values were significantly higher than the surrounding control area. Emissions from the FU were estimated as daily: 0.85 MT, monthly: 1.92 MT, and yearly: 17.91 MT, which were significantly higher than EC. The study also revealed that workers were very susceptible to accidental hazards especially death (91%), and pollution (79%). Environmental consequences and health risks of the workers in shipbreaking industry warrant more attention nationally and internationally at the industry-level.

Analysis of Emission of Greenhouse Gases from Road Transport in Poland between 1990 and 2017

The paper provides the results of the inventory of greenhouse gases (GHGs) from road transport in Poland over the period 1990–2017. To estimate GHGs’ emission from road transport, a standardized methodology was applied, consistent with 2006 IPCC Guidelines for National Greenhouse Gas Inventories and EEA/EMEP Emission Inventory Guidebook 2019, as well as the COPERT 5 software. In the analysis, emissions of fossil carbon dioxide, methane and nitrous oxide were taken into account. Emissions of all considered GHGs were converted to equivalent carbon dioxide. Throughout the subsequent years of emission inventory, emissions of all GHGs revealed an increasing trend, except for methane. The main cause underlying this increase is the dynamic development of motorization in Poland. Thus, GHGs’ emissions were analyzed, taking into account the number of road vehicles and the intensity of their use. An increase in the average specific distance emission was found for fossil carbon dioxide (by ca. 5%) and for nitrous oxide (by ca. 10%), while for methane, there was a decrease (by more than 150%). The GHGs’ emissions from road transport in Poland could be significantly lower if more emphasis was placed on the use of fuels from renewable energy sources.

Analysis of Sources and Trends in Agricultural GHG Emissions from Annex I Countries

The vast majority of the scientific community believe that anthropogenic greenhouse gas (GHG) emissions are the predominant cause of climate change. One of the GHG emission sources is agriculture. Following the International Panel on Climate Change (IPCC) guidelines regarding GHG emission calculation, agriculture is responsible for around 10% of the overall global emissions. Agricultural GHG emissions consist of several emission source categories and several GHGs. In this article were described the results of multivariate statistical analyses performed on data gathered during the period 1990–2017 from the inventories of 43 Annex I countries (parties to the United Nations Framework Convention on Climate Change, UNFCCC, listed in Annex I of the Convention). Trends in the agricultural GHG emissions were analyzed. Generally, the global agricultural GHG emissions are increasing, while the emissions from Annex I countries are decreasing. Apart from the application of urea, emissions from all other sources, such as enteric fermentation, manure management, rice cultivation, agricultural soils, field burning of agricultural residues, and liming are decreasing. Based on multivariate analysis, the most different countries, in terms of GHG emission sources composition in agriculture and emission trends, are Australia, Japan, New Zealand and USA. The rest of the Annex I countries are mostly from Europe and their shares and trends are similar, with slight differences between countries depending, among others, on the date of joining the European Union.