Wednesday, December 11, 2024

Nature Based Solution Carbon Myopia

From a satellite you will not see the butterflies
December 9, 2024
Source: Garden Earth


Multinational forestry company Arauco arrests and burns the homes of indigenous and campesino people living in their ancestral forest territories. Photo: Registro de las familias afectadas por Arauco (Families Affected by Arauco)



Recently, The Guardian featured an interesting article by Tess McClure about the fate of abandoned landscapes, with a special focus on Bulgaria: The great abandonment: what happens to the natural world when people disappear? As of the 2021 Bulgarian census, almost 300 villages were completely abandoned, and more than 1,000 had populations below 30. For someone that has lived in rural Sweden for most of his life, this is of course a rather familiar view. I have visited a number of abandoned hamlet or lone crofts and have even taken down a few such buildings for reuse of the material. Since the 1950s, some scholars estimate up to 400m hectares – an area close to the size of the European Union – of abandoned land have accumulated across the world.

We are not only bad

Many seem to embrace the opinion that abandonment by humans essentially is a good thing as it will “leave more to nature”. This view is obviously based on the notion that humans are inherently bad for nature as well as not being part of it. For sure, it is not hard to find examples of how humans screwed up both nature and their own ecological foundations. But as the article demonstrate, the human influence can also be beneficial for many species, “rather than always being antithetical to nature, human presence can help make life possible for a vast array of species”. A human made pond is not necessarily worse – or better – than a beaver made pond (we have beavers on our farm, I like them very much, even if their logging is a bit irregular).

Most people, in Europe at least, will see forest as the natural pristine stage that we should strive for. But forests are just one of many biomes possible in temperate climates and a “forest” is not necessarily a dense forest plantation but a patch work of woods, swamps, ponds, open spaces etc. Earlier, large herbivores, beavers and other ecosystem engineers kept the land dynamic. Homo agricola took, to a large extent, over that role, in the more traditional forms of landscape management. The semi-natural grasslands of Europe is in that perspectives descendants of those mega-herbivore landscapes. This is not only the case of Europe, research from South America also points to that the mega herbivores created a savanna like landscape in huge parts of the continent.

Carbon myopia

In a recent paper in PNAS, Matthew Hayek and colleagues set out to demonstrate how much carbon that can be stored through afforestation of land currently used for grazing cattle. I will not go into detail, but in their main scenario 184 million hectares of grasslands in temperate climates would be converted to forests and that would sequester 125 Gt carbon dioxide over a period of 75 years. For me, this paper have all the signs of “nature-based-solutions” carbon myopia, i.e. the perspective that how we manage landscapes is all about maximizing carbon storage in ecosystems.

In their view, the choice stand between a very low beef production and a high rate of carbon sequestration though afforestation. They don’t even mention that some of the land they propose to plant full of trees is the land that has the highest biodiversity in Europe. Instead they talk about afforestation as “ecosystem restoration” stating that (dense) forests would be the natural ecosystem in those areas, which has been discussed above.

Their calculations are based on an average of 15 kg of beef produced per hectare and year from the grasslands they propose to plant with trees. In my own very small farm (with five mother cows), the natural grasslands, which has a modest productivity, yields in the range of 80 kg of meat (carcass weight) per year. Research from France and the UK shows a higher production and the Knepp estate, famous for its rewilding, yields 54 kg of live weight (which would equal around 27 kg of carcass weight) from a mix of game and cattle. The figure used indicates that they either made mistakes or included a lot of land that is abandoned or has a very low productivity, which in turn would mean that trees hardly would grow there. The assumed net primary production of pastures is very low, just 1 ton of carbon per hectare and year. In Sweden, which has a harsh climate and most pastures are on marginal lands, it is estimated to 2.8 tons.

The researchers’ calculations are also based on the rather heroic assumption that these forests/plantations will thrive and grow well and not be harmed by insects, fires, storms or any of the other things causing massive damage to trees. In addition, they don’t assume any use of the wood at al, which in my view implies that the land will be bought by government and put in a reserve. Meanwhile their research is also based on the assumption that soil carbon storage in the forests created would be five times as high as soil carbon storage in the grasslands to be planted. I can find no support for that assumption, on the contrary, I find many sources claiming the opposite (that above ground carbon storage is considerably higher in forests than in grasslands is not disputed, the whole definition of a tree is that it has a wooden structure that is built by carbon). In Sweden, research points to that the soil carbon content of grasslands and forests is quite similar but a bit lower in forest soils.

Don’t afforest the Arctic

It is particularly absurd that, according to the research, the Murmansk region has a very high potential for replacing beef from pasture with forests. Murmansk is considerably colder than Anchorage in Alaska and just a bit warmer than Kiruna in Sweden. I find it hard to believe that there is any beef cattle grazing there – most of the region is Sami country with reindeer. Talking about that, recent research also points to that it is a very bad idea to try to afforest arctic and subarctic lands. Interviewed by 8point9 lead author Assistant Professor Jeppe Kristensen says that the unique characteristics of Arctic and sub-Arctic ecosystems make them poorly suited for tree planting for climate mitigation. How much sunlight is reflected back into space, without being converted into heat (the albedo effect), is more important than carbon storage for the total energy balance.

Come down from the satellite please!

This research is just one of many similar articles the last decade, where researchers use global datasets, meta-analyses, artificial intelligence and satellites to determine the best land use – or the best diet, or the best what not. Another such example was the The global tree restoration potential published in Science 2019 which promoted the planting of 0.9 billion hectares forests, popularly interpreted as 1 trillion trees, for carbon sequestration. That article was, rightly, heavily criticized.

In my view, these kinds of research are essentially irrelevant. But they are also harmful if they are construed as policy advise, which the example clearly is: “this work can aid the design and improvement of policies related to natural climate solutions”. They are arrogant, in that that they pretend that we humans know what is the best, that we should – or even can – control nature. They are deceptive, because there are so many error factors and biases built in such assessments and the results are predicated on those initial assumptions anyway. They are prime examples of that as soon as technology allows some kind of new research, it will be made, regardless of its utility. They are harmful, because they neglect – and reject – the local communities that in most cases already know quite well how to manage the land.

Just the other day, UNESCO declared the fäbod system (seasonal grazing in mountain areas) of Norway and Sweden a world heritage.* The seasonal grazing creates a varied landscape with an open forest canopy and very high biodiversity, combining the biodiversity of the forests, bogs, mountains and grasslands. The fäbod system, the Sami reindeer management, my cows or my apple orchard will never fit into any of these global analyses.

Global projections and scenarios, like the one above, disregard people, culture and nature and try to isolate one aspects for optimization, in this case carbon, in other cases something else. But the Earth system and the important human sub-system of the planet cannot and should not be based on optimization or maximization of one aspect, be it carbon, things or money. How humans are in nature is something that is constantly negotiated, adapted and adjusted with and in the landscape. As a minimum, researchers should cross check their data with the realities on the ground. Preferably, researchers should come down to earth and get their hands and feet dirty, instead of sitting in their skylabs. I have some spare shovels.

* The paper identifies even higher potential for afforestation of grasslands in the Eastern USA (and in some other places). I am not in a position to have any opinion about that.

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