Climate change has become one of the biggest issues of our time, not least because of the campaign of Extinction Rebellion to highlight the dangers we face. Mitigation is central to election manifestos with the Conservatives likely to commit to Zero Carbon by 2050. The Green Party has the same aim for 2030 which is surely unrealistic.
At a recent meeting of the Countryside Forum, Professor Allan Buckwell outlined the recommendations of the UK Climate Change Committee under the chairmanship of Lord Deben, formerly John Selwyn Gummer. Aviation and agriculture are not expected to reach zero emissions by 2050 but early action is critical for farming and land use to achieve the targets set at a 60% reduction. This includes a cut in food consumption and waste with no overall increase in imports and respect for other environmental goals such as water and biodiversity.
Apart from carbon dioxide, of which farming has relatively low emissions, significant emissions of methane and nitrous oxide come from agriculture. As is well known, methane is produced during the digestive process of ruminant animals whilst nitrous oxide is a natural product of the nitrogen cycle in the soil. Methane emissions can be reduced by cutting the number of cattle and sheep and by using feed additives that lower production of the gas during digestion. The target for methane from this enteric fermentation is a cut of 37%. Nitrous oxide emissions can be reduced by the better management of soils, especially the amount and timing of nitrate fertiliser applications.
It has long been argued that consumption of red meat and dairy products should be cut. The argument that such foods are bad for our health has now been largely discredited but many still champion the cause and cite saving the planet from greenhouse gas emissions as a persuasive point. Counter arguments were put forward in this column a fortnight ago. Nevertheless, the technical report of the UK Climate Change Committee suggests that consumption of red meat and dairy products must be cut by 20% by 2050. This may seem modest but, bearing in mind the projected increase in population by 2050, it represents a significant fall per head.
It is assumed that this fall in consumption will lead to far fewer cattle and sheep being reared. This, coupled with improved grazing efficiency, should, according to the report, allow over 3.5 million hectares of grassland to go to other uses, made up of a 25% cut in permanent pasture, 17% temporary leys and 29% rough grazing. Improved productivity of arable crops and far less food wastage will give another 715,000 hectares of land for alternative uses.
Not surprisingly, a large part of this redistributed land goes to development, over a million hectares, an increase of 58%. The rest goes to woodland, up 25% to 4.5 million hectares, bioenergy (short rotation coppice and miscanthus) 700,000 hectares, and restored wetlands 717,000 hectares. The target is to plant 30,000 hectares of woodland every year to 2050, 13,000 hectares of agro-forestry and hedgerows, 23,000 hectares of perennial energy crops and the rewetting of 24,000 hectares of peat land.
This is a hugely ambitious programme, bearing in mind that only 1,420 hectares of new woodland was planted in the year to March 2019, far less than the 5,000 hectare target. It will take years to gear up to the level of planting proposed, meaning that the rate will have to far exceed the target in later years. It will also have a profound impact on our landscape. It is clear that much of it will be on grassland, especially rough grazing which is currently in the uplands and downland.
These recommendations are predicated the assumption that growing trees sequester more carbon that growing crops, including grassland. However, there is some evidence that grassland is a more resilient carbon sink than woodland as the carbon is stored underground. In areas subject to drought and wild fires, grassland is less prone to damage and loss of carbon. This ties in with the evidence put forward in Graham Harvey’s book, Grass Fed Nation, the subject of my last column.
The report states that recommendations to mitigate climate change must not compromise other environmental priorities such as water quality and biodiversity. And yet, such compromise is inevitable. A massive tree planting campaign will have a significant impact on the biodiversity of open landscapes, the downland for example.
But the main concern must be the health of our soils. We know that the intensification of agriculture since the ‘green revolution’ of the 1970s, the increased use of fertilisers and pesticides, has degraded our soils to an alarming extent. It has been suggested that, unless drastic action is taken, there is only enough fertility in our soils for another sixty harvests. Reversing this trend and getting more fertility back into our soils must be a priority if we are to feed ourselves as the population of this country expands.
I cannot see how taking 26% of our farmland out of production to grow trees and buildings can improve our soils. 2050 may be a long way off and there may be technological breakthroughs along the way, but making our farming even more intensive could be disastrous. Climate change may be a major priority but it is not the only one.