Climate News Network

UK must balance food farming impacts

January 11, 2016, by Tim Radford

More woodland, less farmland would reduce CO2 emissions in the UK.
Image: SwaloPhoto via Flickr

The UK could reduce its emissions by converting farmland to absorb more carbon dioxide − but risks increasing climate change effects abroad.

LONDON, 11 January, 2016 – British scientists have worked out how to turn agricultural land – which currently produces 10% of the nation’s greenhouse gas emissions – into a “carbon sink” that soaks up carbon dioxide.

The answer is simple: take more land out of food production, restore natural habitats, and allow forests to grow again.

If, in the next 35 years, the UK increased forest cover from 12% to 30%, and surrendered 700,000 hectares to revert to peat bog, that would be enough to meet government ambitions to reduce agricultural greenhouse gas emissions by 80%.

The extra helping of woodland and wetland would go a long way to supporting the UK’s declining population of wild things – including many species that are a source of anxiety for conservationists – and deliver more space for recreation. And the same set of decisions would go some way to reduce the risks of flooding.

Pastoral areas

But after sparing the land for wildlife, farmers would need to increase yields from the remaining agricultural and pastoral areas, say the authors of a new study in Nature Climate Change.

The area proposed for woodland cover would be close to that already achieved in France and Germany, but still less than the average for all Europe.

Such restoration alone would go some way to meeting targets imposed by the government to reduce the threat of catastrophic global climate change driven by greenhouse gas emissions that result from changes of land use and the combustion of fossil fuels.

“Land is a source of greenhouse gases if it is used to farm fertilizer-hungry crops or methane-producing cattle”

Andrew Balmford, professor of conservation science at the University of Cambridge, and one of the report’s authors, says: “Land is a source of greenhouse gases if it is used to farm fertilizer-hungry crops or methane-producing cattle, or it can be a sink for greenhouse gases – through sequestration.

“If we increase woodland and wetland, those lands will be storing carbon in trees, photosynthesising it in reeds, and shunting it down into soils.

“We estimate that by actively increasing farm yields, the UK can reduce the amount of land that is a source of greenhouse gases, increase the ‘sink’, and sequester enough carbon to hit national emission reduction targets for the agriculture industry by 2050.”

The researchers offer more than just a prescription for emissions reduction: their paper identifies a suite of farm and animal management improvements that could raise yields by an average of 1.3% per year until 2050. Food consumption in the UK is likely to rise by 38% by 2050, but the researchers believe the target can be met without increasing food imports.

Food imports

However, a study in the Royal Society’s Interface journal shows that the UK has become increasingly dependent on food imports since the 1980s, with about 50% of its food and feed currently being imported.

In effect, the UK is exporting the environmental impact and leaving producer nations with the challenge of reducing greenhouse gas emissions released in the service of the British supper table.

The UK’s “land footprint” – another term for the global area of land devoted to delivering British food and animal feed –increased by 23% between 1986 and 2009, while associated carbon dioxide emissions increased by 15%, say Henri de Ruiter, an environmental scientist at the James Hutton Institute in Aberdeen, and colleagues.

At present, two-thirds of all cropland needed to produce the UK’s food and feed is located overseas, while 64% of associated carbon dioxide emissions are emitted abroad.

The report concludes: “These results imply that the UK is increasingly reliant on external resources, and that the environmental impact of its food supply is increasingly displaced overseas.” – Climate News Network

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  • The study in the Royal Society’s Interface Journal nails the lie of ending farming for so-called “rewilding” across much of Britain:
    “At present, two-thirds of all cropland needed to produce the UK’s food and feed is located overseas, while 64% of associated carbon dioxide emissions are emitted abroad. . . . These results imply that the UK is increasingly reliant on external resources, and that the environmental impact of its food supply is increasingly displaced overseas.”

    The attempted band-waggoning on the Climate predicament by vegetarian mostly urban interests – who are pushing this non-solution across the media and govt ministries – simply ignore inconvenient science, show a crass lack of knowledge of forestry, and plainly care nothing for the rights of indigenous people of the uplands who’ve been farming them since the neo-lithic.

    Consider first, food security under the ongoing unabated advance of climate destabilization, which is on a rising curve for at least the next 50 years. On a national scale our farmers’ yields are already being hit by the unprecedented extremes of weather events, as in the failures of grain crops to droughts and extreme rains, and in the loss of over half a million ewes and their lambs to the extreme ‘cold-wave’ that hit in the spring of 2013. The idea of increasing farm output 1.3%/yr to 2050 on a 20% reduced land area is simply fatuous wishful thinking.

    Second, our dependence on imported foods and feeds is arguably the UK’s greatest vulnerability to the effects of Climate Destabilization. As Prof Peirs Forster, an IPCC lead author, wrote of the seminal study he led in 2012: “Food Security: Near future projections of the impact of drought in Asia”
    “Research released today shows that within the next 10 years large parts of Asia can expect increased risk of more severe droughts, which will impact regional and possibly even global food security.
    On average, across Asia, droughts lasting longer than three months will be more than twice as severe in terms of their soil moisture deficit compared to the 1990-2005 period. This is cause for concern as China and India have the world’s largest populations and are Asia’s largest food producers.
    Dr Lawrence Jackson, a co-author of the report, said: “Our work surprised us when we saw that the threat to food security was so imminent; the increased risk of severe droughts is only 10 years away for China and India. These are the world’s largest populations and food producers; and, as such, this poses a real threat to food security.”
    http://www.lowcarbonfutures.org/sites/default/files/Food%20Security%20-%20Near%20future%20projections%20of%20the%20impact%20of%20drought%20in%20Asia.pdf

    Given the ongoing increase of extreme droughts in most other major food producing regions, this implies that during the 2020s, or at best in the 2030s, we are liable to see the concurrence of drought-based crop failures in two or more regions, thereby forming the onset of serial global crop failures.

    With buyers for Asia’s immense new middle class already starting to outbid EU food importers, the start of recurring global crop failures – when there are few surplus stocks being traded – will impact the UK particularly hard, as it has an exceptionally high population per hectare of its farmland. The proposal of putting 0.7Mha.s under bog (2.3%) and 4.35Mha.s under additional forestry (18%) is simply fantasy. In reality, we are going to have to bring every bit of useful land into food production to try to avoid famine.

    This critique of incompetent land-use proposals is not about contentment with the present set-up – which is very far from optimal for our predicament. While the notion of ceding 2.3% of land area to bog is ridiculous, not least because of the massive methane outputs to be expected with AGW with methane being 84 times as potent as CO2 over the crucial 20yr horizon (as CNN reported 5 days ago) the expansion of a benign sylviculture across land which isn’t useful for farming is another matter.

    The least useful approach is so-called “natural regeneration” (though under both massive anthro-nitrogen deposition and raised CO2 and AGW ‘natural’ is a delusion). It produces near impenetrable scrub woodland which evolves into high forest over a couple of centuries (Climate Destabilization allowing) but it lacks the social, ecological, economic and carbon benefits of better options.

    The best option is of “Native Coppice Forestry for Biochar and Coproduct Methanol” – or more succinctly, “Carbon Recovery for Food Security.” It entails the planting of native species on non-farmland for cyclical harvesting at ~7 to ~28 years of growth, with the stumps being protected from browsers so that the large root-ball survives and supports rapid regrowth and CO2 intake. The annual harvest is used as feedstock for local village-scale charcoal retorts (thus minimizing haulage energy needs) with simple fairly efficient retorts converting about 67% of the wood’s carbon to charcoal, with the rest mostly going into hot hydrocarbon gasses that hold around 28% of the wood’s energy potential. The charcoal is then milled and primed with a small fraction of suitable compost or livestock dung and distributed to farms for plowing in during normal cultivation both for carbon sequestration and as a very valuable soil moisture regulator and fertility enhancer.

    The hot fuel gasses can be use for local or grid electricity supplies, but given the numerous other options for non-fossil electricity the most benign use is arguably their conversion to the exceptional liquid fuel methanol [CH3OH] as an energy-carrier. This is easily produced, stored and transported, is swiftly biodegradable, has low vapour fire risk, is very clean burning, and serves in boilers, IC and EC engines, gas turbines and also in static or mobile fuel cells; it also has manageable drawbacks in its toxicity, its low energy density, and its need of corrosion-proof tanks. As a co-product it would provide a significant second revenue stream beside charcoal sales to help towards the costs of this sustainable reforestation.

    Having run a small hill farm on the Cambrian mountains for the last 10 years (160acres in-by plus hill commons grazing rights for 700 head) I’ve been able to ask those born and bred as shepherds what fraction of the hill they see as no use for raising sheep. The general consensus is that around 30% now under molinia, gorse, bracken, rushes, heather, etc could be put to coppices without hurting the flocks – and given the present ‘free-trade’ impact on hill-farmers’ incomes a new sustainable enterprise balancing the shepherding would be highly beneficial in encouraging farmers’ children to stay on the land.

    Given that around a third of Britain is high moorland, if native coppice were established across 30% of it, it would reforest about 2.5Mha.s using about 6 billion saplings, bringing total forest area to ~22%. With in-cycle native coppice holding the best biodiversity of any European ecosystem, and providing a huge number of jobs in a new sustainable rural industry, and providing a significant liquid fuel output while also improving farm yields and achieving major carbon sequestration, this option offers a uniquely benign range of benefits.

    However, Britain’s ‘Carbon Debt’ is exceptionally large (due to our responsibility for launching the Industrial Revolution) so to recover the carbon we’ve emitted before the end of this century, besides reforesting in the UK we should look to funding the establishment of a much larger area of projects in “Carbon Recovery for Food Security” in developing countries with suitable conditions. That is both our moral duty – to clean up our mess – and our prudent action to end AGW as rapidly as possible.

    Regards,
    Lewis Cleverdon

  • Consider to also handle more big rain events & the methods provide higher yields, taking a view from Andean hydraulic engineering lasting centuries consider terracing everything in sight to delay flow, introducing as much into groundwater recharge as possible, these contours can be sited & sized to handle farm machinery, the walls porous.

    This was first a thought to deal with flooding as the only long-term solution for that a reaction to recent winter storms.

    You can’t funnel more-n-more flow, the runoff has to be slowed over many square miles of watershed, thus farmers need support to do this, it’s a lot of work with multiple benefits to society.

    Hopefully these thoughts will be welcomed.

  • People hate you because you ofesft your carbon emissions?It’s funny how the simple activity of blogging can make some people hate us. But it’s also good for your skin: it makes it thicker.

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