Saturday, 13 May 2017

Should chicken be taxed higher than beef?

Meat production on farms is responsible for a sizable proportion of our greenhouse gas emissions - both directly from the animals and from producing the feed. Eating less meat is good for us in other ways too, and most of us eat much more than we need. But how to change our habits? One way is to tax meat consumption. How much should such taxes be? A comment piece by Simon Fairlie in the Guardian [1] references two conflicting sources. One, from Oxford University suggests 40% on beef and 8.5% on chicken [2]. The other, from Sweden's University of Agriculture, suggests 40% on chicken and only 28% on beef [3]. This was a surprise - I have always understood beef was much worse than chicken because cattle (and sheep) belch methane. Putting a cash value on environmental impacts is never easy but how can there by such widely differing estimates for similar products?


The damage due to chicken and pork is from other emissions, not so much GHG.
Part of the answer is that the Oxford study was looking only at greenhouse gas emissions whereas the Swedish analysis included nitrogen, phosphorus and ammonia emissions in addition. The first two are a big problem in rivers, lakes and some seas, causing algal blooms and killing off everything else that lives in the water. Nitrogen and ammonia both cause acidification which damages ecosystems and corrodes buildings. Ammonia emissions are mainly from manure while nitrogen and phosphorus can come from manure or from use of fertilisers to produce animal feed. The amounts of emissions vary depending on how the animals are fed and what happens to the manure. For example when manure is spread over a field as fertiliser, injecting it into the soil reduces ammonia production and leaching.

This chart shows the cost of all the emissions in the Swedish study. Considering only the greenhouse gas emissions, beef impacts are ten times that of chicken and 6 times that of pork.

Cost of environmental damage from meat production in the Swedish analysis [3]

Taxes on chicken should be higher because chicken is cheaper.
Taking into account all the emissions Swedish poultry is still only about 60% as damaging as Swedish beef. However, the tax level recommended is higher because chicken is cheaper than beef: they estimated beef costs 140% more than chicken per kg. This is comparable to relative cost in the UK. (Different cuts vary but as of today, in Tesco (ignoring special offers), basic beef mince costs nearly twice as much as whole chicken.) This means that if you add in the cost of environmental damage, the proportional increase is higher for chicken than for beef.

Setting a price on carbon is tricky.
In totalling up the environmental cost of different pollutants, the Swedish study has attributed a financial cost to each one. This is an area that is fraught with difficulty. For the greenhouse gas emissions, they set the price of carbon at the same level as carbon taxes on transportation in Sweden at the time: 1 SEK/kg. This works out in UK money as £90/tonne CO2e which is is five times the current carbon price floor that applies to power stations in the UK (currently frozen at £18/tonne). The Committee on Climate Change has proposed the carbon price should rise to £78/tonne by 2030 and £220/tonne by 2050 [4].

The cost of nitrogen depends on the location - the Baltic Sea is one of the worst.
After the carbon emissions the next largest impact is from Nitrogen and for this the Swedish analysts applied a cost of £22,000/tonne N. The level was chosen to reflect the cost of abatement for nitrogen runoff into the Baltic Sea. The Baltic is particularly vulnerable because it is enclosed on three sides and shallow. High levels of nitrogen in the sea causes algal blooms and dead zones and the Baltic Sea has the largest dead zones in the world; increased ten-fold in the last century [5]. The North Sea is not nearly so bad but there are algal blooms every summer, as you can see in the satellite pictures here. Nitrogen and phosphorus are a  problem in inland waters too. Drinking water from rivers often has to be treated to remove nitrogen as it is a public health hazard, especially for babies.

In the UK, 58% of land is designated Nitrogen Vulnerable.
The nitrogen problem is recognised in the UK too: DEFRA has designated Nitrogen Vulnerable Zones covering 58% of UK land. The main strategy to reduce agricultural runoff is to manage use of fertilisers and manure so in NVZs there are restrictions on how much can be applied and when. How much does this cost? The limits have been set high enough to avoid reduced yields so that should not be a problem and reduced use of fertiliser ought to cut costs. In fact a 2007 report found that more than half the costs to implement NVZs were for administration, and the next biggest cost was for slurry stores, for when the slurry could not be applied [6]. These days there is another way to manage slurry: using it to feed anaerobic digesters to generate methane gas for energy.

It is not clear that the NVZ policy is succeeding. NVZs were first introduced in 1996. However, there has been little decrease, if any, in the proportion of sensitive habitats exceeding limits, at least up to 2008 [7]. The latest review by the Environment Agency recommends an increase of 1.7% in the total area of NVZ [8].

Chicken is safer than beef for the climate, but other impacts should not be forgotten.
Considering greenhouse gas emissions alone, there is no doubt that beef and lamb are far worse than chicken and pork. So I don't need to change my diet or my recommendations on that score. However, it is worth remembering that climate change is not the only environmental impact of our meat eating. The Nitrogen Vulnerable Zones policy is the UK approach to implement the EU Nitrates Directive but even after Brexit we still need clean water in our rivers and seas.



[1] Could a tax on meat help us save the planet? (Simon Fairlie in the Guardian) 21/Apr/17
[2] Pricing food according to its climate impacts could save half a million lives and one billion tonnes of greenhouse gas emissions (Oxford Martin School, University of Oxford) Nov 2016
[3] Green consumption taxes on meat in Sweden (Sarah Säll, Ing-Marie Gren, Swedih University of Agricultural Sciences) Oct/2012
[4] Power sector scenarios for the 5th carbon budget (CCC) October 2015
[5] Dead zones have increased by more than 10-fold in the last century (www.balticnest.org) June 2014
[6] Phase 2: Exploring the relationship between environmental regulation and competitiveness. A case study on the Nitrates Directive (SQW Consulting for Defra) 2007
[7] Environmental Statistics Key Facts 2013 (Defra) jan 2013
[8] Review of Nitrate Vulnerable Zone designations for implementation in 2017 (Environment Agency) 2016

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