Against a backdrop of increasing emission of greenhouse gases (GHGs) that are responsible for global climate change, the South Asia developing member countries (DMCs) of the Asian Development Bank have been witnessing a steady rise in fossil fuels and energy consumption and demand, keeping pace with their economic growth. The region’s major challenge is how to achieve sustained and rapid economic growth for reducing poverty while reducing the overall intensity of energy use, increasing energy efficiency, and substituting to cleaner energy. This report synthesizes the results of national studies on options and costs of reducing GHG emissions in five South Asia DMCs-Bangladesh, Bhutan, the Maldives, Nepal, and Sri Lanka. It examines the economics of cleaner technologies that promote low-carbon development and climate change mitigation, identifies constraints and barriers that reduce incentives to invest in GHG emission-reducing technologies, and recommends actions and enabling conditions to overcome the barriers.
Tag: carbon
Carbon stock in planted woodlots at Kongowe, Kibaha, Tanzania
Forest degradation due to extraction of wood for fuelwood and charcoal production or agricultural expansion is one of the main sources of carbon dioxide (CO2) emissions in Africa. Woodlots can offset CO2 emissions while sustainably meeting the wood demand of local communities. However, the amount and dynamics of carbon (C) stored in soils in coastal area woodlots and the contribution of this practice to climate change mitigation is largely unexplored. This study evaluated wood biomass and C stocks in woodlots, forest reserves and farmland with Acacia crassicarpa Benth., Acacia mangium Wild., and Acacia auriculiformis Benth. to determine their ability to sequester soil C and offsetting CO2 emissions. Woodlots of fast-growing Acacia spp. produced wood (30 to 62 Mg C/ha), which may meet the household fuelwood demand for up to 10 to 20 years and offset up to 31 Mg C/ha of C emissions. Moreover, these species stored soil organic carbon (SOC) (58 Mg C/ha), which was similar to levels in the native forests; demonstrating climate change mitigation capacity. The effects of tree species on SOC was confined to the top 40 cm with native forest consistently recording the highest values. This improvement was attributed to litter and root turnover, C leaching and mixing of SOC by microorganisms, and increased recalcitrant form of SOC with depth. Because of the sandy soil texture in the study site, most of SOC stocks (up to 70% in the bulk soil and 50% in fractionated soils) were in the labile fractions and prone to degradation. Of the tested woodlot species, A. auriculiformis showed the highest promise to produce wood and improve SOC because of higher survival. Our results showed that woodlots systems utilizing the fast growing tree species hold high promise to mitigate atmospheric CO2 increase through on-farm wood supply to alleviate harvesting pressure and accumulation of SOC in the soil
Assessing C-stock dynamics at the landscape level
•UpscalingUpscalingissues: from plot to issues: from plot to landscapelandscape•Study area Study area ––forest transitionforest transitionInformation resolution Information resolution ––CC–stock .stock dynamics dynamics••Spatial resolution Spatial resolution ––land use/cover land use/cover •Temporal resolution Temporal resolution ––CC–stock stock dynamics dynamic
The potential of using Agroforestry as a win-win solution to climate change mitigation and adaptation and meeting food security challenges in Southern Africa
Some of the most profound and direct impacts of climate change in southern Africa over years have been droughts, fluctuations in annual rainfall, extreme temperatures and floods. These have resulted in low and unstable food production, especially maize which is the staple food in most Southern African countries. Furthermore, research suggests that 30% of threatened plant species will be critically endangered or extinct due to drought, thus further worsening food availability, accessibility and stability in the region. Drought is therefore is assumed to be the major obstacle to the achievement of food security in Southern Africa. Agroforestry is emerging as the promising option to sustain agricultural productivity and livelihoods of farmers. We discussed the need for further selection and releasing new tree germplasm with superior capacity to adapt to the changing climatic and ecological conditions in the region. Innovative mechanisms to further enhance the contribution of agroforestry to climate change mitigation and adaptation are examined.
Soil organic matter, biota and aggregation in temperate and tropical soils: effects of no-tillage
The long-term stabilization of soil organic matter (SOM) in tropical and temperate regions is mediated by soil biota (e.g. fungi, bacteria, roots and earthworms), soil structure (e.g. aggregation) and their interactions. On average, soil C turnover was twice as fast in tropical compared with temperate regions, but no major differences were observed in SOM quality between the two regions. Probably due to the soil mineralogy dominated by 1:1 clay minerals and oxides in tropical regions, we found a higher aggregate stability, but a lower correlation between C contents and aggregate stability in tropical soils. In addition, a smaller amount of C associated with clay and silt particles was observed in tropical versus temperate soils. In both tropical and temperate soils, a general increase in C levels ( $approx$ 325 $pm$ 113 kg C $cdot$ha $^{-1}cdot$yr -1) was observed under no-tillage compared with conventional tillage. On average, in temperate soils under no-tillage, compared with conventional tillage, CH 4 uptake ( $approx$ 0.42 $pm$ 0.10 kg C-CH $_4cdot$ha $^{-1}cdot$yr -1) increased and N 2O emissions increased ( $approx$ 1.95 $pm$ 0.45 kg N-N 2O $cdot$ha $^{-1}cdot$yr -1). These increased N 2O emissions lead to a negative global warming potential when expressed on a CO 2 equivalent basis.
Impacts of management practices on soil organic carbon in degraded alpine meadows on the Tibetan Plateau
Grassland soil organic carbon (SOC) is sensitive to anthropogenic activities. Increased anthropogenic disturbance related to overgrazing has led to widespread alpine grassland degradation on the Tibetan Plateau. The degraded grasslands are considered to have great potential for carbon sequestration after adoption of improved management practices. Here, we calibrated and employed the Century model to investigate the effects of overgrazing and improved managements on the SOC dynamics in alpine meadows. We calibrated Century model against plant productivity at Haibei Research Station. SOC stocks for validation were obtained in 2009-2010 from degraded alpine meadows in two communes. We found that Century model can successfully capture grassland SOC changes. Overall, our simulation suggests that degraded alpine meadow SOC significantly increased with the advent of restoration managements from 2011 to 2030. Carbon sequestration rates ranged between 0.04 Mg C ha-1 yr-1 in lightly degraded winter grasslands and 2.0 Mg C ha-1 yr-1 in moderately degraded summer grasslands. Our modeling work also predicts that improve management in Tibetan degraded grasslands will contribute to an annual carbon sink of 0.022-0.059 Pg C yr-1. These results imply that restoration of degraded grasslands in Tibetan Plateau has great potential for soil carbon sequestration to mitigate greenhouse gases.
Roots as sinks and sources of nutrients and carbon in agricultural systems
Roots are a special category of “soil biota” being part of organisms that live in two very different types of environment, aboveground and belowground. As they belong to the organisms that form the main target of all agricultural interventions and are directly involved in the efficiency with which nutrients and water are used for crop production, root knowledge should be “at the root” of any discussion on sustainable agriculture. Yet, little direct attention is given to roots, possibly because of a lack of (1) clear concepts on what to look for and (2) easy (be it quick and dirty) methods to observe the relevant properties in actual root systems.
Advances in Agricultural GHG measurement and monitoring: implications for policy makers
Agricultural landscapes support rural livelihoods, produce food, fiber and energy, and deliver a wide array of ecosystem services. Agricultural practices, including expansion into forest lands, are a major source of greenhouse gas (GHG) emissions. Yet, agriculture can also mitigate GHG emissions through the reduction of nitrous oxide and methane emissions, as well as through carbon sequestration, particularly in the developing world. Despite significant mitigation potential of a range of agricultural practices, limited awareness and low confidence in monitoring of agricultural interventions has inhibited inclusion of agriculture in climate change policy and emissions offset markets. Some examples include the UNFCCC process and domestic cap-and-trade legislation. Sub-national systems, such as the California Action Registry, offer further opportunities for gaining experience with agricultural GHG offsets
Are conditional and realistic REDD + mechanism feasible? A case of a rich forested district in Indonesia: I. Estimation of land use, land use change and forestry carbon emission of Berau District, East Kalimantan
From UNFCCC COP-13 meeting in Bali in 2007, countries agreed that there was an urgent need to take further meaningful action to reduce emissions from deforestation and forest degradation. The demonstration activities of REDD (Reduction Emission from Deforestation and Degradation) is being implemented by many tropical countries worldwide.
Are conditional and realistic REDD + mechanism feasible? A case of a rich forested district in Indonesia: II. Option for setting up reference emission level for REDD+ within REALU in Berau, East Kalimantan
We use national wide land cover map to conduct cluster analysis of drivers or land cover composition and configuration and land use trajectories District with high forest cover-high deforestation (HF-HD) may set their REL at most the same with level of past emission (Historic emission approach) or certain percentage within their Reference Region. Districts with high forest cover-medium deforestation (HF-MD) can set their REL by projecting changes in drivers within their Reference Region (Adjusted historic emission ).District with high forest cover-low deforestation may set their REL based on development plan and spatial plans (Forward loking) Berau district is classified as HF-LD district.