I've posted several times about tree planting, how it takes a long time for a tree to be capturing carbon in any significant way. I've also posted about deforestation, usually linked to an increase in pastureland, specifically for growing beef. Thinking about this, I found a recent article from the FT. Sharing this would be a breach of copyright, so go read it (for) yourself.
The numbers, quite simply, don't work. Adding up the pledges to use land for things like, but not only, tree planting comes to something like 1.2 billion hectares, 1200Mha. That's bigger than Canada. Worse, that's about half of the area we use globally for crop planting. Compound that aggregate proposal with the losses from fire & drought and we clearly have a nonsense.
It is perfectly clear from what I've written before that an obvious positive would be to protect (and manage) existing forest better than we have been doing. Restoring forests would be a further forward step. Curiously, I learn that where Indigenous Peoples and local communities have secure land rights, they vastly outperform both governments and private landholders in preventing deforestation.
Not all carbon is the same. This is the basis for the several fallacies I identify collectively as greenwashing, though others use that term differently. The carbon in coal is not the same as the carbon in a tree, and an old tree is very different from a new one. Maybe this needs explanation in detail, since it may point up the fundamental flaw in carbon-offsetting schemes. The carbon stored in a tree is there while the tree is standing. When it is dies (or is felled) that carbon is only captured if the wood is used (as timber, not as fuel). By comparison, un-mined oil and coal is stable long-term; it is far more a permanent capture than carbon in a tree. The carbon in a fossil fuel is also far more dense – why we use it as a fuel. So a valid question is how much of a tree we keep to use without carbon release (burning, letting rot), rather like wondering how much of a cow we actually eat.
Of course, what is wrong here is that nations are planning to use (saying theyt're going to, eventually) land-based solutions rather than reduced emissions. We like some of the first and a lot of the second but we need to be persuaded that we too can buy into such change; emphasis on the reduction. The 1200Mha is in two parts, 633 and 551 where the first is tree planting (implying serious competition with food growth) and the second is restoration of degraded land (meaning, I think that it is in some sense already considered to be forested space, ans so in this sense more valuable and immediate). A letter in response, from John Lotspeich of Trillion Trees Cambridge, suopports that: The fact remains that we have precious little time left to reverse the negative impacts of climate change. Our first priority must be to cut fossil fuel use, but this alone will not be enough. Trillion Trees strongly agrees with the report’s researchers that focusing on restoring already identified degraded land holds more promise for climate and biodiversity, and poses fewer threats to other dimensions of sustainability than creating unrealistic and inappropriate goals to plant only vast numbers of trees in previously unforested land. The evidence in clear: in these areas restoration can and does have impact. Tree planting is part of that of course, but we do not have to find new lands to bring back our forests.
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Notes, footnotes, references:
A billion hectares: a hectare is 10,000 m², and 100ha = 1 km², so 10⁹ ha = 10⁷ km², 10 million square kilometres. This is the land area of Canada (9.985 Mkm²), and I point out that China is 9.5 and the USA is 9.15, while India is a mere 3.3. 1200 Mha is heading towards four times the area of India; easily 4 times the bit of India trees could be planted on, the bits with soil.
Deforestation runs at about 7.3Mha per year (I found a variety of figures, many quoting ten million (example, [105]) where we have 4060 Mha in total. Thus we lose around a 400th each year. Of course tropical trees are not the same as sub-arctic ones. Since 1990 we've lost around 10% of the total. While this is markedly better than the 1990s (somehing like a 5:3 improvement), it is clearly not sustainable and that is the key test. One partial solution is to turn forest into protected area; we're up to about 8Mha (pretty pathetic, don't you think?). Restoration of forest is not the same as new forestation and generally tree planting is a count of plants, not, as one might hope, in Mha units. Site [106] says roughly 1.9 billion tress are planted annually and yes, we cut down more than we plant. If I use the estimate that there are 3.04x10¹² (trillion) on 4060Mha that suggests 750 per hectare so 1.9 billion trees is 2.5 Mha, about a third of what we remove through deforestation. 422 trees per person. So the area I planted in Cornwall was not enough for two; I'd like the new owners to have been prosecuted for cutting them all down. [107] says forest cover is lower, 3000Mha.
[101] the FT article https://www.ft.com/content/6db18a31-5600-409b-b3db-8c901ecdc499
[102] the originating report 20221101 https://seors.unfccc.int/applications/seors/attachments/get_attachment?code=94ARHA8OJ1G5IW3O7EKD2N89PAYRE9AV It's only three pages long and probably a more useful read than the FT or other press versions of the same thing.
[104] https://www.theguardian.com/environment/2021/may/04/what-is-carbon-offsetting-and-how-does-it-work Points up flaws in the existing systems.
[105] https://www.fao.org/state-of-forests/en/
[106] https://8billiontrees.com/trees/how-many-trees-are-planted-each-year/
[107] https://www.gotreequotes.com/how-many-trees-in-world/
Headlines around climate change and deforestation can be alarmist (“Tree-planting and land pledges would need area bigger than US”, Report, November 2). Indeed, some recent commentary advocates that tree-planting does more harm than good for the planet. The fact remains that we have precious little time left to reverse the negative impacts of climate change. Our first priority must be to cut fossil fuel use, but this alone will not be enough. Trillion Trees strongly agrees with the report’s researchers that focusing on restoring already identified degraded land holds more promise for climate and biodiversity, and poses fewer threats to other dimensions of sustainability than creating unrealistic and inappropriate goals to plant only vast numbers of trees in previously unforested land. The evidence in clear: in these areas restoration can and does have impact. Tree planting is part of that of course, but we do not have to find new lands to bring back our forests. John Lotspeich Executive Director, Trillion Trees Cambridge, UK