Peat: Superhero of the Biosphere, in Need of Global Protection (and Yours)
By Lambert Strether of Corrente.
Patient readers, I’m sorry this is late. Our server problems really threw me for a loop.
I had hoped to take a quick romp through the wonderful world of peat, but as it turns out, peat is complex in every way: By its nature in the biosphere, in its classification, in its modes of destruction. So I am afraid my post on this fascinating substance — which turns out to be the most efficient means of carbon capture on the planet — will not be exhaustive. First, I’ll look at the various definitions of peat. Then I will look at just one or two of the variegated ways we have to classify it, and present a world map of where peat is to be found (more places than you would think). Next, I will look at peat and carbon (capture, and release). Finally, I’ll look at what international organizations are doing to protect peat (not enough), and what you can personally do. (I will not be looking at industrial uses of peat, as fuel for example, because the idea of drying peat out for burning, “responsibly produced” or not, makes me crazy.)
Peat is the surface organic layer of a soil that consists of partially decomposed organic matter, derived mostly from plant material, which has accumulated under conditions of waterlogging, oxygen deficiency, high acidity and nutrient deficiency.
In temperate, boreal and sub-arctic regions, where low temperatures (below freezing for long periods during the winter) reduce the rate of decomposition, peat is formed mainly from bryophytes (mostly sphagnum mosses), herbs, shrubs and small trees.
In the lowland humid tropics, peat is derived mostly from rain forest trees (leaves, branches, trunks and roots) under near constant annual high temperatures.
In other geographical regions peat can be formed from other species of plants that are able to grow in water-saturated conditions. For example, in New Zealand peat is formed from members of the Restionaceae while in tropical coastal fringes peat is formed in mangrove. New types of peat may still be found.
And they complete the backtracking process:
Definitions of peat vary across disciplines and between authorities for different purposes and there is no universal agreement that is applicable in all circumstances. This is unfortunate because it affects estimates of the area of peatland and determination of important attributes of peat, especially volume and carbon content.
So here we have peat’s public relations problem again: You can raise money for a trophy animal; everybody knows what a polar bear is. But how do you raise money for a squishy, mire-y entity — there is, apparently, controversy as to whether bogs and mires are the same, or not — that can’t be defined? More to the point, how do you get global stakeholders to defend the indefinable, let alone fund efforts to study and preserve it?
As a sidebar, a particularly attractive aspect of peat bogs is that they create the conditions for their own reproduction. From (sorry) Wikipedia:
The characteristics of some bog plants actively promote bog formation. For example, sphagnum mosses actively secrete tannins, which preserve organic material. Sphagnum also have special water retaining cells, known as hyaline cells, which can release water ensuring the bogland remains constantly wet which helps promote peat production.
If I interpret the IPS correctly, sphagnum occurs in “temperate, boreal and sub-arctic” bogs, so it would be interesting to know if other plants in other parts of the world have a similar effect; I would imagine so.
With even peat’s NGO unwilling to define it, it should come as no surprise that peat is also hard to classify. The Food and Agriculture Organization of the United Nations (FAO), in “Nature and Management of Tropical Peat Soils,” has drily hilarious summary:
The classification of peats and organic soils poses many problems…. Existing classification systems are based on:
i. Topography and geomorphology.
ii. Surface vegetation.
iii. Chemical properties of the peat.
iv. Botanical origin of the peat.
v. Physical characteristics of the peat.
vi. Genetic processes within the peatswamp.
“Existing classification system” is very much plural; every one of the buckets contains multiple classification systems! Of all of these, I’ll pick out a sample from “iv. Botanical origin of the peat,” because that gives insight into peat formation:
The botanical origins of peat features highly in several classification systems. Frequent reference is made in the literature to Sphagnum peat which is extensive in temperate and tundra regions. It occurs also in the tropics at high altitudes, for example, in Rwanda/Burundi. Peats can be divided into major vegetation types such as moss peat, sedge peat, heath, saw-grass peat, Cyperacea peat and forest or woody peats. One of the problems of this type of classification is that …. An understanding of the botanical composition of peat is valuable because many of the other characteristics of peat are related to it. For example, peats developed from reeds, sedges and various trees are generally two to four times richer in nitrogen than those from Sphagnum mosses and Eriophorum sedges (Lucas 1982). Lignin content is likewise often related to botanical origin. Woody peats generally contain low contents of cellulose and hemicellulose and large amounts of lignin. Since cellulose and hemicellulose decompose easily and lignin is the resistant fraction, the proportion of the latter increases as the peat decomposes, particularly in woody peats…. The wood content is also significant when considering the economic feasibility of reclamation and potential use.
(I like “reclamation.” From whom was the peat bog reclaimed, pray tell?) The layering and the lignin might be thought to point us in the direction of coal, and so it does. From Geology.com, “What is Coal?” we find that peat is the lowest rank of coal, where “rank progression corresponds to their level of organic metamorphism”:
(You can see that on a geological time-scale, burning peat is the equivalent of eating our seed-corn.) Since peat, compressed and heated over time, becomes coal, you might think that peat bogs are really, really good at carbon capture, and you would be right! But before going there, let’s take a quick look at how widely peat is distributed throughout the world.
Since peat hard to classify and even to define, mapping peat worldwide is not an easy task. However, the PEATMAP project has tried. From Catena, “PEATMAP: Refining estimates of global peatland distribution based on a meta-analysis,” we have description of the mapping process:
[T]he spatial extent of peatlands is poorly constrained. We report the development of an improved global peatland map, PEATMAP, based on a meta-analysis of geospatial information collated from a variety of sources at global, regional and national levels. We estimate total global peatland area to be 4.23 million km2, approximately . Our results suggest that previous global peatland inventories are likely to underestimate peat extent in the tropics, and to overestimate it in parts of mid- and high-latitudes of the Northern Hemisphere. Global wetland and soil datasets are poorly suited to estimating peatland distribution. For instance, tropical peatland extents are overestimated by Global Lakes and Wetlands Database – Level 3 (GLWD-3) due to the lack of ground-truthing data; and underestimated by the use of histosols to represent peatlands in the Harmonized World Soil Database (HWSD) v1.2, as large areas of swamp forest peat in the humid tropics are omitted.
: purifying water, sometimes mitigating flooding and providing a home for rare species. And they beat nearly every system when it comes to carbon storage. .
“From a climate perspective, [peatlands] are the most essential terrestrial ecosystem,” says Tim Christophersen, a senior program officer with Forests and Climate at the United Nations Environment Programme.
Unlike rainforests or coral reefs, , to the extent that we don’t even know where all of the world’s peatlands are.
Once again, poor public relations. And the mapping project above. More:
Scientists used to believe that the vast majority of the world’s peatlands were in boreal and temperate areas, such as Minnesota, but we now know that the tropics are also home to huge areas of peatlands.
Early in 2017, scientists announced they had discovered the world’s largest tropical peatland in the Congo. The massive peatland – covering an area larger than New York State – stores as much carbon as is emitted from burning fossil fuels globally in three years, about 30bn metric tonnes.
“Many countries still do not know if they have peatlands,” Christophersen says.
A study published this year in Global Change Biology estimates that tropical peatlands – the most important in terms of carbon storage – may cover three times more land than previously estimated. But they are difficult to find because not all wetlands contain peat. The only way to know for sure is to send researchers to sample the soil, and that takes money.
Well, yes. Focusing on carbon alone, it’s clear that if peatlands capture enormous amounts of carbon, burning and despoiling them must release enormous amounts of carbon. And such is the case. Naturally, peat being peat, there are problems. From the Leeds Ecosystem, Atmosphere & Forest (LEAF) Centre, “The health burden of fires across Equatorial Asia“:
Peat fire emissions are challenging for scientists to model as they occur close to the ground, making it difficult for satellites to detect the depth of the burn.
Once started, peat fires are hard to stop. Fire in the treetops can race across the forest at 10 kilometres an hour, while smouldering peat can take a week to travel half a metre. But both can happen at once, the scientists report. “The tropical peatlands of South-east Asia are a clear demonstration of how human activity can alter the natural relationships between ecosystems and fire,” said Susan Page, professor of physical geography at the University of Leicester, UK, and a co-author of the latest report. In a Nature study in 2002, she calculated that a dramatic and sustained forest fire in Indonesia in 1997 may have sent 2.5 billion tonnes of carbon into the atmosphere – a figure that could have added up to 40% of all the emissions from all the fossil fuel burning that year. “Tropical peatlands are highly resistant to natural fires, but in recent decades humans have drained peatlands for plantation agriculture,” she said. “People cause the deep layers of peat to dry out, and also greatly increase the number of fire ignitions. It’s a double threat.”
Globally, drained peatlands and peat fires emit about 1 Gt carbon dioxide (CO2)-equivalents per year which corresponds to 10% of the greenhouse gas (GHG) emissions from agriculture, land-use change and forestry (Smith et al., 2014). … Drained peatlands rank among the largest GHG sources from agriculture and forestry in many European and Asian countries, even when they cover only a small percentage of the national area (Tubiello et al., 2016, Drösler et al., 2008). To achieve implementation of the goals given by the Paris Agreement, reducing emissions from drained peatlands is urgently required. The current “4 per mille” initiative aims to increase carbon stocks in soils as a compensation for anthropogenic GHG emissions (Minasny et al., 2017). However, the protection of the large carbon stocks in natural peatlands and the reduction of emissions from drained organic soils by rewetting is direly needed to not counterbalance any potential success in the management of mineral soils.
Peat and International Organizations
With peatlands being an ecosystem of such importance, we’d expect serious international efforts to preserve them. This does not appear to be happening. Turning to the IPS, we look at their strategic plan, excerpting from “Strategic Goal 3: To improve governance of peatlands through involvement with International Conventions,” and pulling out the “measurable objectives”:
The IPS will establish (by date) a mechanism to stimulate and monitor the provision of information to and contacts with policy makers and will solicit regular feedback from policy makers.
The IPS will continue to participate at relevant international events and through the provision of joint position papers with appropriate partners. It will provide members and stakeholders with information on the work of international organisations and conventions relevant to peatlands and peat, and with reports on IPS attendance at meetings of these bodies.
So, information sharing and conference attendance improve the governance of peatlands. Perhaps. I don’t know the NGOs and government agencies that govern? regulate? nudge? cajole? climate change issues, but it’s not clear to me that the IPS does either. So I decided to see if the World Economic Forum, in its Great Reset project, was even aware of peat. Sadly, no.
I also ran a search. Again, no.
So, if any international organization is actively defending peatlands — as opposed to sharing information about them and going to conferences — I am not aware of it. I would be very happy to be educated on this point by readers!
What You Can Do
There are things you can do. One obvious action is to destroy the market for peat-based compost by refusing to buy it, urging others not to, and preventing home and garden shops from carrying it. From Gardens Illustrated:
The carbon content in peat is enormous. When you dig out peat and allow it to oxidise, all the carbon dioxide is released into the atmosphere, which contributes to global warming.
Surprisingly, it is gardeners, not commercial growers, that use most peat compost. The main reason is that there are millions of gardeners and they tend to use big pots and window boxes, so the volume of compost needed is very high, whereas commercial growers tend to raise young plants in small pots.
A second thing you can do is oppose “reclamation” of peatlands in your own jurisdiction, as you might a pipeline or a landfill. For example:
Scotland To The Rescue – Again
World heritage status for Scottish peat bogs could help UK hit net zero goals – the Flow Country, an expanse of almost uninterrupted blanket bog that stretches over about 4,000 sq km of Caithness and Sutherland – larger than Hampshire or Kent! pic.twitter.com/wQZs5j1AnV