Much wildlife is grazing-dependent
Climate Change, Grazing & Land Use March 2020 There is a lot of talk in conservation circles and the media on the impact of land use on climate change. However it is a complex subject and it would appear that carbon flows are not understood by most; for example the difference between carbon emissions from the use of fossil carbon and carbon emissions which are merely recycling of atmospheric carbon. When we burn fossil fuels we are adding new carbon to the atmosphere, the cause of global warming. However when animals belch methane this does not result in an increase on atmospheric carbon: they are merely recycling the carbon fixed by the plants they eat. Certainly the methane they belch is a strong greenhouse gas, but its time in the atmosphere is short compared to carbon dioxide. Animal husbandry, particularly intensive farming, certainly does release a new greenhouses to the atmosphere but this is through the use of fossil carbon in transport, farm machinery, fertiliser & pesticide production, and the processing of animal feed. However most of these outputs will also apply to crop growing as currently managed. The only way to reduce these carbon outputs is replacement of fossil fuels with renewable energy, with no input of fertilisers etc. dependent on fossil fuels for their manufacture.
Otherwise moving to a vegetarian diet will not make much difference to the climate! Certainly replacement of tropical rainforest to animal pasture in some parts of the world does add to the amount of carbon in the atmosphere, but this is not relevant to UK farming. In the UK before the advent of the industrial manufacture of fertilisers, animals were an essential part of crop rotation, the dunging effect of animals being essential to maintain long-term soil fertility. If animals are no longer part of the farming scene, then soil fertility can only be maintained through the continual use of industrial-manufactured fertilisers (although the use of legumes such as clover can fulfil the nitrogen deficit). Can these be produced in a carbon-neutral way? The return to more environmentally extensive farming does rely on animals. Additionally, a significant proportion of the UK’s biodiversity is grazing dependent, such as chalk grassland, limestone grassland and lowland heath: if animals are no longer part of the agricultural scene, then this biodiversity will be lost. And does wool not have a bright future as a non-fossil fuel, non-plastic textile?
Climate change mitigation & nature conservation not always on the same side! There appears also to be a strong belief amongst conservationists that conservation of habitats and climate mitigation are always on the same side, but there is no a priori reason why this should be the case! There are times when, if we want to conserve the landscapes and natural habitats of the UK, we will have to decide which is more important: climate mitigation or preventing the loss of habitats. The papers in this new ‘Climate change & land use’ section of my website address these issues, and also point out that tree planting in the UK does not necessarily mitigate climate change.
The return of forestry ploughing for tree establishment: an example of a land use practice inimical to climate change mitigation Many upland soils (podsols, peaty gleys, shallow peats, deep peats) are tend to be inimical to good tree growth. Hence the land is ploughed to break open the impermeable ironpan, to access the mineral soil below and to dry out the ground. However these soils are carbon rich and left alone will continue to accumulate carbon, perhaps more than the trees will eventually fix. Ploughing will release this stored carbon to the air, contributing to global warming. Incidentally, the ploughing also destroys any existing vegetation pattern, destroys any existing archaeology in its path, increases the rate of water run-off (contributing to downstream flooding) – and adds permanent scars to the landscape (a network of parallel lines).
*January 2020* LAND-USE AND CLIMATE CHANGE IN THE UK: THE NEED FOR A STRATEGIC ECOLOGICAL OVERVIEW DOWNLOAD HERE In the topical discussion on the issue of climate change and land management there generally seems to be a lack of any strategic ecological overview. These are my thoughts on some of the issues about which I think there needs to be a lot more discussion Text with photographs, A4 6 pages, 5.4 mb
James H C Fenton ECOLOGIST
Armadale, Skye. 2018. Note ditches through deep peat Glen Orchy. 2020. Dense mounding, almost as bad as ploughing Trees & drainage dry out the soil, releasing stored carbon Glen Garry, visible from the A9. 2020 Dava Moor, Moray. 2018 Above L.Scammadale, Argyll. 2019 Pentland Hills. 2019 Glen Orchy. Note mounding is in areas of dark vegetation – the most carbon-rich areas
*March 2020* ‘Simplified’ because it tries to summarise complex issues and does not include all greenhouse gases Contents 1. Terrestrial carbon stores in Scotland 2. Carbon flows 3. Difference between a carbon store & a carbon sink 4. Trees & carbon flows 5. Peatland & carbon flows 6. Carbon cycling in natural ecosystems 7. Land use & global warming 8. Action to mitigate global warming DOWNLOAD HERE Diagrams & text, A4 6 pages, 160kb