Methane. A review

Earth's atmosphere is changing because of emissions of pollutants and greenhouse gases. Carbon dioxide emissions are important and result in half of the warming of the atmosphere. Pollutants from burning like black carbon (soot), nitrogen oxides and sulphur oxides have adverse health effects and result in cooling. Pollutants have long masked the greenhouse effect, but improved air quality through reductions in air pollutants increase the warming. Atmospheric processes are intricately linked. Methane is central in all atmospheric chemistry. Methane is also important as a greenhouse gas. Although carbon dioxide should be reduced to prevent global warming, it is relatively cheap to reduce the non-CO2 greenhouse gases such as methane at the same time. Methane's concentration in the troposphere, after a long period of stabiliszation, is rising again since 2006. Here I will give a review on methane, its atmospheric chemistry, its emission sources and global budget

Methane : its role in climate change and options for control

This study on CH4, (its role in climate change and options for control), aimed at a scenario analysis to assess future climate change under reduced methane emissions. At the same time improving the quality of CH4 emission inventories and estimating the costs of emission reductions between 2010 and 2100. In this thesis 28 major options to control or mitigate methane emissions from different sources were identified. The effectiveness and costs of these options were assessed. This resulted in a database of different options and costs for all the different sources of methane. This database was subsequently used to update the methane module of the Integrated Model to Assess the Greenhouse Effect and expand it with a simple costing module. The IMAGE model was further improved by this work by Van Amstel on methane reduction strategies. The thesis concluded that significant reductions in global methane emissions are both technologically feasible and, in many cases, very cost effective strategies for climate change mitigation. Their wider implementation in coming years and decades will largely depend on the policy and market signals delivered by the UNFCCC conferences of the Parties, but failing to make full use of the potential for methane mitigation globally will inevitably make effective mitigation of climate change through reduction of carbon dioxide emissions alone all the more difficult. The scientific community can provide improved methane flux estimates, reduce uncertainties and enhance our understanding of key climate change feedback mechanisms, such as methane emissions from high latitude wetlands and from clathrate deposits. The technology to deliver deep cuts in methane emissions from a host of important sectors is already available. To put methane mitigation at the heart of a robust and well-integrated framework for tackling global climate change, improved national and international policy is required to facilitate rapid technology transfer and provide financial incentives that will ensure that the myriad potential opportunities for the effective mitigation of methane emissions around the world are made real. It is therefore recommended to remove market barriers and to increase attention for methane abatement options through international cooperation and learning from proven technology. One possible route to overcome market failure in methane reduction is international cooperation between front runners and countries willing to learn. Public-private partnerships can be used to stimulate this international cooperation for example in the International Methane Initiative.</p

Integrated assessment of climate change with reductions of methane emissions

We have been living in the anthropocene era since about 1950, and evidence of human influence on the natural ecosystems and climate is mounting. Reductions of greenhouse gas emissions are needed to reduce the effects of climate change in the future. In an integrated assessment with the IMAGE model (integrated model to assess the global environment) the effect of methane reductions has been analysed. Reductions were calculated against baseline scenarios P and Q. Scenario P describes a prosperous world with an economic growth of 3% per year and a relatively low population outlook, resulting in a population peak in 2050 with 8.7 billion people and a reduction to 7.1 billion in 2100. Q is a contrasting scenario. Q has the same population development but describes a world where the modernization of the OECD countries has spread to the other world regions between 2000 and 2100. A shift takes place from an economy relying on heavy industry towards a services based economy with a high proportion of public transport. In both baselines traditional biomass burning is replaced by modern liquid biomass fuels used for transport and electricity production. In the Q scenario less meat is consumed. Six reduction strategies for methane were analysed: no reduction of methane (P1 and Q1), moderate reduction of methane (P2 and Q2) and maximum reduction of methane (P3 and Q3