Suchergebnisse

The GHG (greenhouse gas) mitigation potential from the agricultural sector is set to increase in coming decades. Much of the agricultural mitigation potential lies in developing countries where systems are dominated by smallholder farmers. There is therefore an opportunity for smallholders not only to gain environmental benefits from carbon friendly practices, but also to receive much needed financial input, either directly from carbon financing, or from development agencies looking to support carbon friendly activities. However, the problem remains of how to quantify carbon gains from mitigation activities carried out by smallholder farmers. Landscape-scale quantification enables farmers to pool resources and expertise, which can put participation in carbon markets and access to other funding sources, within their reach. Therefore, funding agencies, governments and NGOs are increasingly recognizing the benefits of taking a landscape approach to GHG quantification. This paper gives an overview of approaches that have been taken to date for landscape-scale GHG quantification, covering both measurement and modelling and the reliance of one upon the other. The discussion covers ground-based measurement approaches for carbon stock changes in biomass and soils, methods for measuring GHG flux and the application of remote sensing techniques. Computational approaches for estimating carbon stock changes and GHG emissions are discussed, in addition to the use of more complex dynamic ecosystem models. This is followed by an analysis of some of the resources that are available for those wishing to do GHG quantification at the landscape scale in areas dominated by smallholders. This analysis is intended to provide an aid to funding agencies, government agencies, NGOs, academics and others. Information for this section comes from questionnaires distributed to selected resource developers.

In the course of the transformation to a greenhouse gas-neutral society in the second half of the 21st century, the use of synthetic energy carriers based on renewable electricity or biomass is under discussion. This project evaluates the environmental impacts of technical and logistical options for the generation of such energy carriers on the basis of environmental impact categories such as global warming potential, acidification or land use. The production of five products (Fischer-Tropsch fuels, methanol, synthetic natural gas, biomethane and hydrogen) was examined based on various process steps/procedures and their current and future technical data. By using regional factors for Germany, Europe, and the Mediterranean region - like the availability of renewable energy carriers such as wind or PV and of raw materials such as carbon or water as well as transport routes to Germany - these processes were combined to form supply paths for these energy carriers. Using the method of life cycle assessment, the environmental effects were analysed for today and 2050. In addition, the costs for plant construction and operation were estimated. The results show that synthetic energy carriers generally have a significantly lower global warming potential than today's fossil reference products due to the use of renewable energies. However, the production of electricity generation plants and associated economic processes - such as steel and cement production - can still make a relevant contribution to the global warming potential if they are not also greenhouse neutral. At the same time, it is this production of the necessary plants that leads to (sometimes significantly) increased burdens compared with the fossil reference in almost all other impact categories, most notably in terms of water and land use. This study therefore also provides indications of which environmental impacts must be further reduced in the future.