The Centre for Alternative Technology in Wales is a significant non-government advocate of action to reduce climate change. Its 2010 Report, Zero Carbon Britain (ZCB) 2030, includes proposals for reducing farm and land use greenhouse gases that are far more ambitious than the coalition government’s. ZCB 2030 confidently claims that by adopting its proposals, “in principle, the land use sector can completely decarbonise itself, mop up the residual emissions from the rest of the UK economy, and at the same time deliver improved food security, healthier diets and enhanced biodiversity.”

Like the government, ZCB 2030 bases its proposals on the assumption that the carbon price will provide incentives to farmers and other land-based businesses to reduce their greenhouse gas emissions.

So let’s see what this assumption means and whether it stands up to scrutiny.

What’s a carbon price?

There are at least five different kinds of carbon price. In the UK, the government has decided to set the carbon price used in farming and land based businesses, based on its estimates of the cost of policies to reduce one extra tonne of greenhouse gas emissions. This is called the Marginal Abatement Cost (MAC) of reaching the farming emissions reduction target. The trouble is that apparently estimated abatement costs vary a lot depending on the model used for reducing carbon emissions.

How do carbon prices affect farmers’ decisions about reducing greenhouse gas emissions?

A high carbon price is crucial for ZCB 2030′s ambitious plans for reducing farming and land greenhouse gases. The way the process works is: if the costs of carbon emissions are very high, in terms of the damage they will cause, and farmers have to pay these costs, they will benefit greatly from reducing their farm’s greenhouse gas emissions, so they’ll switch to lower carbon ways of farming. The whole thing is based on the idea of cost/benefit analysis, which states that actions should only be taken if economic benefits outweigh the costs.

The theory is that high carbon prices can work to reduce farming greenhouse gas emissions in the following ways:

• an emissions tax based on the carbon price incentivises farmers to reduce emissions in order to avoid having to pay the tax
• a variety of payments for ecosystems services incentivises farmers to conserve and restore environmental resources, like peatlands which store carbon in the soil
• investment of tax money in research and infrastructure generates new low carbon ways of farming and protecting the environment

Is the Zero Carbon Britain 2030 carbon price realistic?

I haven’t been able to figure out what kind of carbon price ZCB 2030 is using. But the Report assumes that the 2030 carbon price will be much higher than the government estimates. ZCB 2030 says that by 2020 the carbon price would need to be more than £200/tonne in order to provide incentives for farmers to switch from farming which produces high greenhouse gas emission to farming which actually sequesters more carbon than it emits. This carbon price is way higher than the government’s 2009 valuation that the 2020 carbon price would be £60/tonne, with a range of plus or minus 50% – ie it could be between £30 and £90.

And the government estimated that in 2050 the non-traded price of carbon (ie the price that applies to farming and land businesses) would be £200/tonne, again with a range of plus or minus 50%, while for 2050 ZCB 2030 estimates that the price will be £500/tonne.

The discrepancy between ZCB 2030 and government carbon prices is bigger if you use the 2010 Climate Change Committee figures, which revised the 2009 government values downwards to around £32/tonne in 2030 as a consequence of the fall in emissions caused by the recession. A falling carbon price could undermine incentives to reduce emissions, so the government has announced an “underpinned” carbon price of £30/tonne in 2020 and £70/tonne in 2030. In other words, the government won’t let the carbon price fall below these levels.

Zero Carbon Britain 2030′s proposed farming changes that will reduce greenhouse gas emissions

ZCB 2030 assumes that high carbon prices will make it:

• very costly for farmers to emit greenhouse gases
• profitable for them to store carbon in soils and plants
• profitable for them to grow energy crops

Accordingly, ZCB 2030 outlines how farmers can respond to these price signals by switching to farming foodstufffs with low associated greenhouse gas emissions, capturing and storing carbon in soil and plants and growing far more energy crops.

Storing carbon in soil and plants

Zero Carbon Britian 2030 proposes “radical reform” of farming that will shift the focus to “locking” carbon into the soil and vegetation.

This would involve:

• conserving natural stores of carbon in peat soils, existing woodlands and biomass products like wood, used in building
• actively capturing and storing atmospheric carbon in natural systems and products – like soil, plants and products made from plants (often called biomass products)

This active carbon sequestration would mean changing to best soil management practices that would increase the amount of carbon stored in the soil. It would also mean producing biochar and adding it to the soil.

It would mean establishing new woodland and growing more energy crops – such as straws; grasses harvested for energy, by means of anaerobic digestion that produces biogas; hemp; short rotation coppicing and miscanthus.

FInally, building methods would need to change in order to use more wood and other new building materials designed to store carbon.

There may be some problems with ZCB 2030′s estimate that adding 4 million tonnes/year of biochar to UK soils would sequester 16 million tonnes of carbon dioxide equivalent a year. Biofuelwatch reported in 2009 that there is a lack of scientific evidence that adding modern biochar to soils increases soil carbon storage. And a 2011 report points out that “a recent scientific review by 14 scientists from 12 research institutes published in Nature” concludes that predictions about biochar as an effective means of storing carbon strongly rely on laboratory studies whose results are not borne out in real soils. The report says that “sequestration strategies” that use biochar “must be re-evaluated”. La Via Campesina, the worldwide peasant farmers’ movement, identifies biochar as a false solution to climate change.

As well as biochar’s contested soil carbon storage capabilities, there are problems with producing 4 million tonnes of biochar a year. This would require burning around 28 million tonnes of biomass (plant and animal materials) a year (since only about 12-14% of the biomass that goes into the process ends up as biochar). That seems like a lot of plant and animal material to me. Where’s it going to come from?

Far more energy crops

ZCB 2030 states that farmers could grow a lot more energy crops, including short rotation willow coppicing and miscanthus, and that this would help decarbonise electricity generation and transport. These crops would produce replacements for aviation kerosene and diesel used in shipping, as well as providing biomethane to replace coal and gas in back-up power stations that would be needed when wind turbines were not generating electricity. 

Switching from livestock farming to low-carbon crops

Zero Carbon Britain 2030 proposes that farmers will respond to a high carbon price by switching away from farming that emits a lot of  greenhouse gases, (mostly beef and dairy products from grazing livestock), towards “nutritionally- equivalent crop products” that emit far less. They estimate that this switch would reduce land and farming greenhouse gas emissions by 60-70%, but they recognise that this goes against “strong preferences, vested interests and the trend towards higher consumption of meat.”

This product switching would reduce:

• production of meat and dairy by grazing livestock by 80-90%
• production of foodstuffs from non-grazing livestock (eg pigs and poultry) by 10-60%
• imports from about 40% to 20% of food (there would be no imports of livestock products and feed – currently, the UK imports about 50% of concentrated feed for livestock)

Product switching would also increase crop-based foodstuffs by 60%.

Changes to land use

Radically reducing livestock numbers would free up a lot of grassland: ZCB 2030 proposes there would only be 20% of the 2010 numbers of sheep, mostly in hill and upland areas; 10% of beef cattle, mostly in lowland pastures and some upland areas; and 20% of dairy cattle in rotational grazing (where the grass is alternated with other crops) and improved grassland.

As a result, ZCB 2030 estimates that grazing land would reduce from around 11 million to under 2 million hectares. This grassland would then be freed up for more energy crops. But an Environment Agency report says that changing land use to plant energy crops on permanent grassland can negate any emissions savings from biomass energy generation.

Upland areas would provide ecosystem services such as:

• carbon sinks, where peatland is restored and managed
• supplies of water for reservoirs
• biodiversity

The acreage of legume crops and oil crops as a source of livestock feed would also increase, since imports of soya-based livestock feed would stop.

What we will eat in Zero Carbon Britain 2030

These proposals need the British public to change our “behaviour and lifestyle”, for instance by eating less meat. The ratio of animal to plant protein in our diet would shift from 55:45 to 34:66. Basically we would eat more fruit and vegetables and less meat and dairy products.

The main problem…

As I see it, the main problem with ZCB 2030 proposals for decarbonising farming and land businesses is its reliance on the market. In the 1970s and 1980s, environmental problems were tackled and solved by regulation, but in the 1990s, governments and important environmental groups and individual activists turned to market-based policies like environmental taxes, tradeable emissions permits, carbon offsets, and so on. This has led to the situation where it can reasonably be stated that “the market is the answer regardless of the question and even irreversible climate change is just another opportunity for private profit.”