Nature based solutions: CO2 removals in 2022?

Market for nature based carbon offsets

Is the nascent market for nature-based carbon offsets working? We appraised five projects in 2022, and contributed $7,700 to capture 440 tons of CO2, which is 20x our own CO2 footprint. This 11-page note presents our top five conclusions. Today’s market lacks depth and efficiency. High-quality credits are most bottlenecked. Prices rise further in 2023. A new wave of projects is emerging?

Tigercat: forestry and timber innovations?

Tigercat patent review

Tigercat is a private company, founded in 1992, headquartered in Ontario, Canada, with c2,000 employees. The company produces specialized machinery for forestry, logging, materials processing and off-road equipment. Our Tigercat patent review has found a moat around reliable, easy-to-maintain, mobile and efficient forestry equipment.


In the modern forestry industry, we think a crew of 1 x feller buncher, 1 x skidder and 1 x loader can harvest 250 tons of timber per day, with a fuel economy of 1.2 gals/ton of wood. This kind of productivity is up at least 150x from pre-industrial forestry.

We wonder whether there is increasing opportunity for companies in the forestry supply chains, as themes such as sustainable timber (e.g., cross-laminated timber), sustainable forestry, reforestation, sustainable packaging and biochar gain traction in the energy transition.

A key challenge for the industry is that off road machines are subject to higher stress levels, and forestry machines are subject to even higher stress levels. Key components subject to very severe operating loads are axles, wheel spindles, drivetrain components and pump drive gearboxes.

Overall, our Tigercat patent review finds an array of specific, intelligible and focused patents, improving the reliability, maintainability, mobility and fuel economy of forestry equipment.

This is especially applicable for harvesting equipment, such as feller-bunchers, mulching equipment, and novel areas that may matter in the energy transition such as site preparation, re-planting and biochar production. These are all focus areas in the patents.

We have profiled the CO2 credentials of different wood uses as part of our ongoing forestry research.

Energy history: how much wood can be cut in a day?

How much wood can be cut in a day

This data-file estimates how much wood can be cut in a day, using back-of-the-envelope calculations, across 500-years of industrial history. In medieval times, a manorial tenant might have gathered 250kg of fallen branches in a good day, containing 1,000 kWh of thermal energy. A modern feller-buncher is 150x more productive. But a modern energy analyst is little better than a medieval peasant. Harvesting wood as a heating fuel is expensive, inconvenient and prone to risks.


Wood as a heating fuel: volume, mass and energy?

Wood fuel quantities are most commonly measured in cords. One cord is defined as 128 cubic feet of wood, which can be visualized as a 4′ tall pile, over an 8′ x 4′ area. Mass and energy content will vary. But as an approximation, 1 cord of wood weighs 1.4 tons, and 1 ton of wood contains 4,000 kWh of thermal energy, which is materially less than other fuels.

500-years: how much wood can be cut in a day?

Wood was the dominant heating fuel of the medieval energy system. We think that a manorial tenant could have gathered 250kg of fallen branches on a good day, limited by the ability to carry only 20-25 kg on a single trip, and secondarily by an absence of comfortable footwear.

Mechanization offered a 2-4x productivity gain by the early industrial era, using handheld saws, axes, and horses to pull felled trees towards water-courses, where they could be floated downstream and processed (painting below from the 1890s).

How much wood can be cut in a day

By the mid-20th century, chainsaws and trucks offered 2-4x further productivity gains, so a professional logging crew could harvest 10,000 kWh of energy per person per day. About the same as 1.5 tons of a typical coal grade. Although debatably, it is less harmful to nature to burn a tree that has already been dead for 400M years than cut down a living one.

Today the logging industry is another 15x more productive again, using slightly terrifying machines such as feller-bunchers to fell, pluck and de-limb entire trees, before cutting them to length, and stacking them for transport. Specialist manufacturers include Tigercat, John Deere, Caterpillar. We are increasingly doing more work on sustainable forestry and screening nature-based CO2 removal projects.

How much wood can be cut in a day

Energy crisis: stocking up on heating fuel?

Somewhere in between the productivity of a medieval peasant and the modern forestry industry, a typical person today can likely collect 0.5-2.5 tons of firewood in an 8-hour day, containing about 2,000-10,000 kWh of useful energy. The precise number depends on the use of modern power tools, the type of wood, and the experience of the person.

Here I am illustrating the point below, after a stint working at a forest plot in Estonia. We cleared out some thicket from this land last year, and have now started the gruelling task of planting proper trees in the gaps. Last weekend, it took about 1.5-hours to gather these thinned branches, drag them across to the road-side, then chop them up using shears and an axe.

How much wood can be cut in a day

Energy metrics: can I do better than a medieval peasant?

(1) Energy quantities. In 1.5 hours, I gathered almost 100kg of wood, which might contain 400kWh of thermal energy. For comparison, a typical bath consumes 4kWh of thermal energy, so this is about “100 baths”. Overall, a typical household consumes 40-60kWh of heat energy per day in the winter. So if I wanted to meet my household’s heating needs by gathering firewood, trips like the one above would need to be a weekly occurrence.

(2) Energy return on energy investment of harvesting this woody debris is actually quite good. My fitness tracking app tells me I burned about 350 kilocalories while doing this back-breaking labor. Which translates into an EROEI of 100x, if the result is 400kWh of wood fuel. Although the EROEI falls to around 10x if we also include the gasoline consumed in driving out to my forest-plot and back (for comparisons, please see our EROEI datafile).

(3) Cost. Unfortunately, if a typical person values their weekend time at $35/hour, and manages to generate 300 kWh of net fuel per hour, then their implied energy cost from gathering firewood comes out to about 12 c/kWh. This is equivalent to paying $35/mcf for natural gas. This is not much cheaper than European natural gas in the 2020s. And debatably, you may also need to add the costs of buying forest land, garden equipment, a woodshed and obligatory Patagonia outdoor wear.

(4) Carbon credentials. The carbon credentials of different wood uses are evaluated in our note here. In this case, I am going to argue that the wood I gathered would simply be decomposing if it were not used up. However, there is clearly a limit to how much fallen debris or thinned material you can collect from a woodland before you are chopping-down older growth trees and contributing to deforestation (the largest single CO2 emissions source on the planet, and more than all the world’s passenger cars).

(5) Other drawbacks. A final conclusion from this exercise is that it is quite inconvenient to have to cut, transport and dry your own fuel; then kindle a fire; then clean up the ashes and air out the smell of smoke from the living room. Out in the forest, there were some slightly hair-raising moments involving the axe, which could have greatly impaired my beloved Excel keyboard shortcuts. And my wife was also quite cross about the state of the car.

Conclusions: better to use modern energy?

How much wood can be cut in a day? The data-file linked below contains our calculations for the tonnage and energy content that can be harvested across different forestry practices over the past 500-years. It is a reminder of the virtues of the modern energy system, if only we could get back to an energy surplus.

CO2 removals: teak plantations, Nicaragua?

Nicaragua reforestation case study

The “Nicaragua High Impact Reforestation Program” should remove over 100,000 tons of CO2 from the atmosphere, by row-planting teak trees across >500 hectares of former pasture land in Nicaragua. It is our fourth detailed case study of nature based CO2 removals in 2022, with a price of $45/ton, and a passable score of 70/100 on our framework. But this Nicaragua reforestation case study also illustrates some challenges and debates around nature-based solutions.


Great virtues of this project are that it is real, incremental and measurable. The CO2 credits are certified by Gold Standard, and we were able to review 100 pages of documentation from independent auditors, verifying the CO2 removals; which seem to be measured conservatively, including a 20% ‘buffer’ for reversals.

This region of Nicaragua has been 80% deforested for cattle-grazing. There is a clear CO2 benefit to reforesting former pasture-land. GDP per capita is below $2,000 in the country. Hence it is also helpful for well-meaning investors to provide capital to convert degraded land into carbon-absorbing forests. CO2 credits contribute to the return on that investment.

Furthermore, around 25-30% of the total area in the project is residual forest, especially around water-courses, which will be preserved. This is nature-positive. Although CO2 credits are not being issued against this forest conservation.

However, this particular reforestation project is 100% row-planted teak, which will be harvested and re-planted on a 20-year cycle. Teak is not even native to Central America, but originates from South-East Asia. Some critics might argue that a short-life, row-planted mono-culture is not really ‘a forest’. And if you are not creating a forest, is it really re-forestation?

This is the logic behind the project achieving a score of 70/100 on our framework. Further details and debates are laid out in the data-file, exploring whether this Nicaragua reforestation case study can be considered ‘permanent’ (yes and no!), ‘biodiverse‘ or ‘nature positive’. So are the key numbers from our review.

We have made a $1,000 allocation to this project, in order to offset 22 tons of CO2. Our goal is to support one nature-based CO2 project each month, and to size the allocation according to the ‘score’ each project achieves on our framework.

Carbon offsets: cost of CO2 removal per tree planted?

Cost of CO2 removal per tree planted

The purpose of this data-file is to calculate the cost of CO2 removal per tree planted, using a simple modelling methodology, based around the tree’s risked and discounted future carbon absorption.


The reason this is important is that some organizations, especially charities, are committing to plant trees in return for financial contributions. But in order to compare this option with other CO2 abatement options, we need to convert the units into $/ton of CO2.

This is actually quite difficult and variable. ‘Planting’ can range from scattering seed balls through to raising seedlings for 1-3 years in nurseries and then planting them out carefully. ‘Trees’ can also ultimately range from 40kg mangroves through to the 2,000 ton General Sherman Redwood.

Our methodology estimates how many tons of CO2 will be absorbed per tree as it grows to maturity, then ‘discounts’ future CO2 removals into ‘present CO2 terms’, then risks the calculation according to the survival rates and permanence of the CO2 absorption.

A good rule of thumb is that tree-planting should cost $15/ton of CO2 that is removed on a risked net present carbon basis. Numbers can realistically vary from $10-100/ton, but will mostly be in the $15-30/ton range.

Costs are likely lower than fully certified and verified nature-based CO2 removals. The trade off between lower-cost and lower-quality CO2 removals can be evaluated on a case-by-case basis (examples here).

Our key points on the cost of CO2 removal per tree planted are highlighted in our article here.

Savanna carbon: great plains?

Savanna Carbon

Savannas are an open mix of trees, brush and grasses. They comprise up to 20% of the world’s land, 30% of its annual CO2 fixation, and we estimate their active management could abate 1GTpa of CO2 at low cost. This 17-page research note was inspired by exploring some wild savannas and thus draws on photos, observation, anecdotes, technical papers.

Wood use: what CO2 credentials?

Wood use CO2 impacts

The carbon credentials of wood are not black-and-white. They depend on context. This 13-page note draws out the numbers and five key conclusions. They count against deforestation, in favor of using waste wood, in favor of wood materials (with some debate around paper) and strongly in favor of natural gas.

CO2 intensity of wood: context by context?

Wood use CO2 impacts

CO2 intensity of wood in the energy transition is calculated in this data-file.


Context matters, and can sway the net climate impacts from -2 tons of emissions reductions per ton of wood through to +2 tons of incremental emissions per ton of wood.

Covered contexts include deforestation, sustainable forestry, commercial thinnings and gathering fallen biomass; which is cross-plotted against wood fuel displacing gas, wood fuel displacing coal, wood material displacing steel/cement, wood products displacing plastics and paper.

Calculations can be stress-tested in the data-file, including all of our carbon accounting and counterfactuals for the fair, apples-to-apples CO2 intensity of wood. For more on our carbon accounting philosophy, please see here.

Recent Commentary: please see our articles here and here.  Specifically, this data-file lays out the calculations for our 13-page note. It highlights climate negatives for deforestation, climate positives for using waste wood and wood materials (with some debate around paper), and very strong climate positives for natural gas.

Global wood production: supply by country by year?

Global wood production

This data-file quantifies the global wood production, country-by-country, category-by-category, back to 1960, using granular data from the FAO. About 4,000 m3 of wood are harvested per year (2GTpa by mass).


The split is that 50% is used as fuel, 20% as paper/pulp and 30% as longer-lasting materials which may help remove CO2 from atmospheric circulation.

It varies greatly by economic development levels. Africa and India use 90% of their wood as fuel. The US and Europe use 20%. As Korea industrialized, wood use as fuel fell from 70% in 1960 to 7% in 2020.

Overall, wood energy has declined from 11% of the world’s primary energy mix in 1960 to c4% today. However, it remains stubbornly high in less developed countries (e.g., 30% in Africa, data below).

Global wood production

Deforestation remains the largest source of CO2 emissions globally, and the data suggest shortages of oil, gas and coal could exacerbate this ecological disaster. If coal, oil and gas prices all treble, then by extension, the relative value of wood-based fuels approximately trebles too.

To read more about the global wood harvest and production, please see our article here. We think the CO2 credentials of wood in the energy transition range from -2.0 tons/ton to +2.0 tons/ton, depending heavily on context, but also creating opportunities (note here).

Finnish forests: a two billion ton CO2 case-study?

Finland forests CO2 removals

Can forestry remove CO2 from the atmosphere at multi-GTpa scale? This 19-page note is a case study from Finland, where detailed data goes back a century. 70% of the country is forest. It is managed sustainably, equitably, economically. And forests have sequestered 2GT of CO2 in the past century, offsetting two-thirds of the country’s fossil emissions.

Copyright: Thunder Said Energy, 2019-2023.