Tuesday, October 17, 2017

False methane math

Because of the difference in nature between methane and carbon dioxide we should cease expressing the climate effect of methane in carbon dioxide equivalents. This has important implications for policy as well as for the assessment of different strategies for minimizing the climate effect of production or lifestyles. Culling all cows may sound like a great proposition if we use the conventional metrics but is actually a rather futile effort to curb climate change.   

If you put ice in your drink it will cool off rapidly, but if it is hot in the air it will soon be warm again. That is perhaps the best way to describe the effect on the climate of a one-time reduction of methane emissions. It would give a rapid effect but after some decades it would hardly be noticeable. The same apply for a one-time increase in methane emissions, it leads to immediate warming, but the long term effect is small. This is very different from carbon dioxide, of which we hardly can measure the short term effects of a decrease or increase in emissions, but the effect will last for thousand years.  How can we then measure their climate effect with the same unit?

The most common way of comparing the greenhouse gas effect of different gases is to express them as carbon dioxide equivalents, i.e. how much carbon dioxide corresponds to a pulse (a one-time) emission of the gas in question. The most common way of expressing this is by the unit GWP-100, which express the cumulative forcing over hundred years. For methane (CH4) the GWP-100 value is 28, i.e. a pulse of methane emission of 1 kg corresponds to a pulse of 28 kg carbon dioxide emission. But we could equally use other figures as shown in the table below (from the IPCC Synthesis report 2014). For example the GTP-100 measures the actual temperature change after 100 years. With that measurement a pulse of 1 kg methane corresponds only to 4 kg of carbon dioxide. The actual effect on the temperature is probably more in line with what most people expect of the comparisons between greenhouse gases. 

But neither the GWP nor the GTP can properly reflect the difference between short lived greenhouse gases such as methane and long-lived carbon dioxide. In the article New use of global warming potentials to compare cumulative and short-lived climate pollutants in Nature Climate Change  Myles Allen and colleagues demonstrate how the calculations for expressing methane in carbon dioxide equivalents hides a lot of information. For short-lived greenhouse gases the comparison with carbon dioxide based on a pulse of emissions of both gases gives a reasonably correct result only in a time span of a few decades. In the longer term, the more correct comparison is between a pulse of carbon dioxide and an increase in methane emissions. Or as expressed in the article

“The notion of ‘CO2-equivalent’ pulse emissions of cumulative and short-lived climate pollutants [SLCP, among which methane is the most important one, my comment] will always be ambiguous because they act to warm the climate system in fundamentally different ways. To date, this ambiguity may have had only a limited impact, not least because emission reductions have so far been relatively unambitious.”

… and

“GWP100  can be used in the traditional way, comparing pulse emissions of different greenhouse gases, to specify how mitigation of both short-lived and cumulative climate pollutants may reduce the rate and magnitude of climate change over the next 20-40 years, but only over that time. To achieve a balance between sources and sinks of greenhouse gases in the very long term, net emissions of cumulative pollutants such as CO2 need to be reduced to zero, while emissions of SLCPs simply need to be stabilised.“

The long term effect of a pulse emission of methane is thus very small after 100 years. What really matters in the long term is that CO2 emissions are cut dramatically. On the other hand, in the very short term, the effect of decrease in methane emissions is huge. It can be tempting for politicians or others who want to show quick results to focus on reduction of methane emissions and ”buy time” for the needed cuts in carbon dioxide emissions, or simply neglect it as the buck is passed to other generations.

A recent article in Energies by researchers from Chalmers University in Gothenburg makes the case that a culling of all domestic ruminants (they express it as a shift in diet to a non-ruminant diet, but that clearly assumes that all of them are slaughtered) would “buy us” time to delay the necessary transition of the energy system. But this one-time radical decrease of methane emissions doesn’t really take away the need for a fundamental change of the energy system, it just allows for a few years more of continued carbon dioxide emissions. After that we still need to cut them as much as without any cut in methane emissions.

The argument from the researchers why culling cattle is better than reducing carbon dioxide emissions is purely economic, it is simply cheaper in their analysis (which also assumes a 5% discount rate…). It is not clear how they calculated the loss of income for hundreds of million people and the loss of animal traction and transport for even more people, or how the loss of all the 187 million cows in India (12 % of all cows in the world) would even be possible. But I assume this is totally irrelevant for the researchers and their economic calculations. After all, in the big scheme, a rich European's trip to a tropical holiday resort has a higher “value” than the yearly income of an Indian farmer.

There is a case for a reduction in methane emissions to avoid that the climate reaches certain ”tipping points”, such as the melting of the permafrost. However, that argument only holds if carbon emissions are simultaneously reduced, thus not for the scenario where methane reduction is used to buy time as in the cull the cow scenario above. A cut in fossil fuels will also give a direct reduction of methane emissions as fossil fuel extraction is the biggest contribution to anthropogenic methane emissions. In addition, the climate effect of methane emissions from fossil fuels is higher than the methane from cattle, because the carbon in fossil methane adds to the long term carbon dioxide increase of the atmosphere while the carbon in the methane from ruminants is part of a biological cycle, and will be taken up by the grass eaten by the cows etc.


So much for the big picture, what about the emissions and grazing cattle? Do the more than hundred million people who primarily get their livelihoods from pastoralism or extensive grazing and their cattle, destroy the climate?   

If we see a ruminant and the pasture that feeds it, this is a balanced system where there is no increase in methane emissions. The methane emissions are just the same every year. As we seen above that will have had a small effect on the climate, meaning they have contributed to global warming. But equally important is that the methane emissions from these animals don’t cause a continued warming, the annual emissions are balanced by equally high breakdown of earlier emission. A lifecycle analysis, however, will treat this as a new system and each animal as an addition to emissions, i.e. a pulse emission in the GWP-100 metric, and therefore it will concluded that the cattle and its products cause huge emissions. This demonstrates that the results of a lifecycle assessment is determined by its assumptions and the metrics used, and why lifecycle assessments are not a good tool for use when assessing complicated biological systems.

But haven’t the number of ruminants increased rapidly? And haven’t huge areas been converted to pastures lately?

The number of cattle and buffaloes have indeed increased with 50% since 1961 (the human population grew with 135 % in the same period). Most of these additional cattle are fed with cultivated feedstuffs (silage, grains, corn, soybeans) either in US style feedlots for beef or in modern dairy production, i.e. they don’t graze. We have all heard the stories about massive tracts of land, often rainforest being converted to pasture. And it is true on a regional level, but globally there are also other trends where massive tracts of pasture is converted to forest or arable land. Most rich countries experience that pastures are converted to forests, for example in Sweden around 80 percent of all pastures have been abandoned the last 100 years. The global area of grasslands even shrank since 2000. Between 1961 and 2014 grasslands only increased with roughly 8 % globally.

Assuming that these lands were grazed by methane emitting ruminants already 1961, the net increase in methane emissions caused by grazing ruminants represent a very minor contribution to climate change, and most of the warming caused by these animals occurred long time ago. This doesn’t account for the laughing gas emissions (N2O) which is another climate gas. But it also doesn’t consider the sequestration of carbon in grassland soils. Both these merit own articles and are subject to huge scientific arguments.

To continue keeping these animals, keeping the pasture grazed, doesn’t contribute anything to further climate change. Culling them would – possibly --  result in a one-time small reduction of global warming, hardly noticeable for future generations*  If it is worth it, is a question of values and of which food system we favour, and not a strategy for tackling climate change.   

*If the land were converted to arable farming it would emit more carbon which would cause more global warming.

Wednesday, September 20, 2017

Why True Cost Accounting is not a good concept for markets and public policy

The value of ecosystem services associated with farming can be substantial. In 2012,  the estimated value of production from Japanese agriculture was 9.5 trillion Yen (some US$120 billion at 2012’s rate) while the value of the ecosystem services were estimated to 8.2 trillion Yen, i.e. almost as much as the production value.

The external costs of farming can be equally substantial. According to FAO’s report Natural Capital Impacts in Agriculture the external costs of global production of maize, rice, soybean and wheat are 1.7 times higher than the product value.  

Lately, there are several initiatives working with the concept ot True Cost Accounting, e.g. TEEB, The Sustainable Food Trust and the company Eosta

Full and fair payment to farmers for ecosystem services and other public good as well as the inclusion of costs for environmental damage sounds like a good idea. Who could object to that?

I could.  In short; 

-To calculate the real cost of production is not at all simple, and the calculated cost of using one method, say 1 kg of synthetic fertilizer, will differ enormously in different parts of the world, even within the same country.
-All valuation of nature is subjective. In a hugely unequal world it will be the priorities of the wealthy that determines the values.
-It would require an administrative system and controls which would make the current CAP, and organic regulations, look like a kindergarten.
-The major objection to true cost accounting is that it puts even bigger pieces of nature under the rule of the market, a trend that I believe is contrary to the desired development.

A bit longer:

One can question the benefits of valuing ecosystem ser­vices in monetary terms, especially as the most valuable of these services have unlimited value and no known alternative.

As the value of ecosystem services and the external costs together are much higher than the product value, there will be increasing competition between the provision of food and the provision of ecosystem services. It will be the priorities of the wealthy that determines the value. We can today already see that rich people compensate for their carbon emissions by appropriation of poor people’s resources, e.g. by tree planting in Africa. This is done both on a individual level and in intergovernmental agreements.

There is also the question of how we perceive nature. It seems that we increas­ingly confuse ‘value’ and monetary values, and there is a case for us avoiding underwriting this confusion by assigning prices for natural and social capital.

To define the external cost of a certain practice on a specific farm is simply not doable. The cost of the use of 1 kg Nitrogen is probably zero in some parts of the world and very big in others. The report Natural Capital Impacts in Agriculture concludes that external costs of wheat production in Germany is almost nine times higher than the product value, mostly owing to the use of fertilizers. In Canada the external costs of wheat production is “only” 1,3 times higher than the product value. If these external costs were included wheat farming in Europe would totally cease.

In a complex system such as farming, the internalization of all social and environmental costs and compensation for ecosystem services or other public goods would only be possible with very extensive and extremely detailed regulations. Just look at the European Union’s agri-environmental program which is but a small step in this direction. Such a system would probably still be neither fair, nor efficient, and would, in many ways, represent a control of farms more severe than under Soviet rule.Such a system would also be totally alienating for farmers and furhter strengthen the dominance of "experts" in the farm sector.

There are no indications that markets for ecosystem services will be based on any of the scientific calculations that are now made to show the value of these services. The market value will be very differ­ent from the real value or the use value. This can be seen very well in the price for carbon credits, which has no relationship to the cost of climate change. 

Moreover, the payments to farmers for providing public goods will not reflect the value of the public good but the compensation the farmer needs to make the required effort – which may be considerably higher or lower than the value of the services themselves. (The WTO agreement on agriculture explicitly prohibits compensation to farmer for the “real value”, something that most proponents seems to be unaware of).

The commercialisation of farming led to the privatization of land, water, genetic resources and knowledge. A similar development can be expected when ecosystem services are going to be commercialized and external costs can be offset by measures on other places. Payments for ecosystem services leads to markets for ecosystem services which leads to privatization of ecosystems.

“It is a fantasy to believe that we can devise a rigged market sys­tem in which ‘corrected’ prices would tell the whole truth about the opportunity costs of everything in the world, and automatically optimize the scale of the economy relative to the ecosystem, as well as the allocation of resources within the economy” wrote Herman Daly, the creator of the concept of a steady-state economy.

A governmental study on ecosystem services in Sweden concludes that economic valuation and compensation may, in many cases, not be the best way to maintain ecosystem services. It says that monetary valua­tion is not reliable or is completely unsuitable for complex situations that involve numerous ecosystem services, such as soil formation, water regulation and pollination. This, in a nutshell, is farming. 

It seems foolish to rely solely on market-based measures to tackle the biodiversity issues and ecosystem services associated with farming. Instead of fiddling with hundreds of different subsidies or fees that regulate what farmers should or should not do, we need to look at the whole system.

Farming is the most significant human management system of the planet; the future of humans on the planet largely rests upon how we manage our farmscapes. If we accept this then it has profound implica­tions for agricultural policy for it means that ‘managing the planet’ is almost as an important task of the farming system as supplying food. But farmers are not very oriented to being land stewards through the market system. On the contrary, modern day farming has removed much of the land husbandry and stewardship which was previously an integral part of a regenerative farming system. It is not realistic that ‘the market’ will take care of managing the planet. It is also not desir­able, as the Earth is our common home and responsibility and should be managed as such.