Emissions/Description: Difference between revisions
Jump to navigation
Jump to search
Oostenrijr (talk | contribs) m (Text replace - "SO2" to "SO<sub>2</sub>") |
Oostenrijr (talk | contribs) m (Text replace - "CH4" to "CH<sub>4</sub>") |
||
| Line 59: | Line 59: | ||
===Land-use related emissions=== | ===Land-use related emissions=== | ||
CO<sub>2</sub> exchanges between terrestrial ecosystems and the atmosphere computed by the LPJ model are described in [[Carbon cycle and natural vegetation]]. The land-use emissions model focuses on emissions of other compounds, including greenhouse gases ( | CO<sub>2</sub> exchanges between terrestrial ecosystems and the atmosphere computed by the LPJ model are described in [[Carbon cycle and natural vegetation]]. The land-use emissions model focuses on emissions of other compounds, including greenhouse gases (CH<sub>4</sub>, N2O), ozone precursors (NOx, CO, NMVOC), acidifying compounds (SO<sub>2</sub>, NH3) and aerosols (SO<sub>2</sub>, NO3, BC, OC). | ||
For many sources, the emission factor ([[#General approaches|Equation 1]]) is used ([[Emission table]]). Most emission factors for anthropogenic sources are from the [[EDGAR database]], with time-dependent values for historical years. In the scenario period, most emission factors are constant, except for explicit climate abatement policies (see below). | For many sources, the emission factor ([[#General approaches|Equation 1]]) is used ([[Emission table]]). Most emission factors for anthropogenic sources are from the [[EDGAR database]], with time-dependent values for historical years. In the scenario period, most emission factors are constant, except for explicit climate abatement policies (see below). | ||
There are some other exceptions: Various land-use related gaseous nitrogen emissions are modelled in grid-specific models (see further), and in several other cases, emission factors depend on the assumptions described in other parts of IMAGE. For example, enteric fermentation | There are some other exceptions: Various land-use related gaseous nitrogen emissions are modelled in grid-specific models (see further), and in several other cases, emission factors depend on the assumptions described in other parts of IMAGE. For example, enteric fermentation CH<sub>4</sub> emissions from non-dairy and dairy cattle are calculated on the basis of energy requirement and feed type (see Component [[Livestock systems]]). High-quality feed, such as concentrates from feed crops, have a lower CH<sub>4</sub> emission factor than feed with a lower protein level and a higher content of components of lower digestibility. This implies that when feed conversion ratios change, the level of CH<sub>4</sub> emissions will automatically change. Pigs, and sheep and goats have IPCC 2006 emission factors, which depend on the level of development of the countries. In IMAGE, agricultural productivity is used as a proxy for the development. For sheep and goats, the level of development is taken from EDGAR. | ||
Constant emission factors may lead to decreasing emissions per unit of product, for example, when the emission factor is specified on a per-head basis. An increasing production per head may lead to a decrease in emissions per unit of product. For example, the | Constant emission factors may lead to decreasing emissions per unit of product, for example, when the emission factor is specified on a per-head basis. An increasing production per head may lead to a decrease in emissions per unit of product. For example, the CH<sub>4</sub> emission level for animal waste is a constant per animal, which leads to a decrease in emissions per unit of meat or milk when production per animal increases. | ||
A special case is N2O emissions after forest clearing. After deforestation, litter remaining on the soil surface as well as root material and soil organic matter decompose in the first years after clearing, which may lead to pulses of N2O emissions. To mimic this effect, emissions in the first year after clearing are assumed to be five times the flux in the original ecosystem. Emissions decrease linearly to the level of the new ecosystem in the tenth year, usually below the flux in the original forest. For more details, see Kreileman and Bouwman ([[Kreileman and Bouwman, 1994|1994]]). | A special case is N2O emissions after forest clearing. After deforestation, litter remaining on the soil surface as well as root material and soil organic matter decompose in the first years after clearing, which may lead to pulses of N2O emissions. To mimic this effect, emissions in the first year after clearing are assumed to be five times the flux in the original ecosystem. Emissions decrease linearly to the level of the new ecosystem in the tenth year, usually below the flux in the original forest. For more details, see Kreileman and Bouwman ([[Kreileman and Bouwman, 1994|1994]]). | ||
| Line 76: | Line 76: | ||
===Emission abatement=== | ===Emission abatement=== | ||
Emissions from energy, industry, agriculture, waste and land-use sources are also expected to vary in future years, as a result of climate policy. This is described using abatement coefficients, the values of which depend on the scenario assumptions and the stringency of climate policy described in the climate policy component. In scenarios with climate change or sustainability as the key feature in the storyline, abatement is more important than in business-as-usual scenarios. Abatement factors are used for | Emissions from energy, industry, agriculture, waste and land-use sources are also expected to vary in future years, as a result of climate policy. This is described using abatement coefficients, the values of which depend on the scenario assumptions and the stringency of climate policy described in the climate policy component. In scenarios with climate change or sustainability as the key feature in the storyline, abatement is more important than in business-as-usual scenarios. Abatement factors are used for CH<sub>4</sub> emissions from fossil fuel production and transport, N2O emissions from transport, CH<sub>4</sub> emissions from enteric fermentation and animal waste, and N2O emissions from animal waste according to the IPCC method. These abatement files are calculated in the IMAGE climate policy sub-model FAIR (Component [[Climate policy]]) by comparing the costs of non-CO<sub>2</sub> abatement in agriculture and other mitigation options. | ||
}} | }} | ||
Revision as of 10:34, 1 July 2014
Parts of Emissions/Description
| Component is implemented in: |
Components:and
|
| Projects/Applications |
| Models/Databases |
| Key publications |
| References |
|
