300 years ago, American settlers wandered into North America, “discovering” and gradually “conquering” native American land or occupying no-man’s land. In Europe Tsar Peter the Great passed away and Johann Sebastian Bach was composing his masterpieces.
In China the Qing Dynasty brought a wave of advancement in literature, art, and philosophy. India, with the Moghul Empire declining and regional Marathas and Sheikhs gaining popularity, faced a period of increased British East India Company influence over the sub-continent… all this while wooden sail boats roamed the seas for trade, piracy, and colonization.
One aspect all parts of the world during that time had in common is that practically all their energy and building materials came from biomass. Wood, planks, fodder, food… all came from mother nature… trees and plants.
Today, biomass is considered a “green” renewable source of energy reported as having little or even zero “greenhouse gas” or “climate impact”. It doesn’t matter which government’s “net-zero” pathway you consider, biomass is mostly portrayed as 100% clean and “green” in the literal sense. Let’s have a critical look at this interesting, thousand-year-old source of energy.
- Biomass, the energy of the sun and of our atmosphere
Let’s take a step back first. It may have been 5th grade when I was exposed to the idea that carbon, from carbon dioxide, is the basis for all life on earth… because CO2 is what plants breath. And we also learnt that plants (or biomass for that matter) are the lifeforce of practically every living being on Earth.
Clearly, carbon dioxide (CO₂) is foundational to life on Earth, because it drives the critical process of photosynthesis. Of course, CO2 is also a “green-house gas”, while water vapor is undisputably the most important and most abundant greenhouse gas accounting for over 90% of the total “green-house gas effect” (Simpson et al 2024 [1] and Coe et al 2022 [2]).
The energy from the sun, whether it be utilized through biomass, or solar energy, sparked this dream of an “energy transition” towards an infinite “renewable” source of energy that can power our modern lives. I have previously written about wind and solar power (Are Wind and Solar up for the challenge?) taking on a system view, mapping out how “non-renewable” wind and solar truly are at a national level. I have not yet written about biomass, so let’s take this opportunity and have a look.
2. How important is biomass for our energy systems?
Biomass makes up about 9% (>15.000 TWh) of our total primary energy supply (Figure 1). While this percentage is rather small, in absolute terms we use more biomass today than we did 200 years ago when the industrial revolution took off.
Back then, biomass, mainly wood, was the main energy source. Today, it’s one of many, but as our overall energy demand has grown, so did biomass usage.
In terms of tonnages, the over 15.000 TWh of global biomass would translate to about 4 billion tons p.a. if we assume 15 GJ/ton to be a realistic average energy density. To put this into perspective, you can compare this to about 9 billion tons of coal p.a. providing over 25% of primary energy globally. But all these are just very rough estimates only to give you a sense.
For the number minded reader, the below table summarizes some of the key statistics of today’s energy use. Incredible that 60% of biomass is still used for heating and 15% for fueling the cooking in kitchens around the world. Sources: [10, 11, 12, 13, 14, 15, 16, 17, 18]
For electricity, the Nordic countries Finland (33%), Sweden (29%) and even Netherlands (21%) have the highest biomass share burning wood chips, pellets, biogas, and also biomass waste… the larger and important biomass consumers in absolute terms are of course China 200 TWh (2,5% of their total electricity), United States 60 TWh (1,5%), Brazil 55% TWh (8,5%), Japan 50 TWh (4,5%), and Germany 45 TWh (7,5%).
Figure 1: Estimates for global biomass energy and sectoral breakdown, Schernikau based on various sources : [10, 11, 12, 13, 14, 15, 16, 17, 18]
Heat and industry (~40% of total primary energy): Biomass is primarily used for residential and industrial heating, accounting for ¾ of total biomass use. Globally over 10% of energy for heat and industry comes from biomass. Up to 80% comes from coal and gas. The numbers are all estimates as the global statistics are not consistent.
Cooking: especially in large parts of Africa, biomass remains an important energy source for cooking, about 2 billion people globally still cook with biomass which has a negative effect on their health.
Electricity (~40% of total primary energy): Biomass contributes only a small part of electricity (700 TWh or ~2,3% of total 30.000 TWh). Nevertheless, the global biomass consumption for electricity generation is greater than the total electricity consumption of Germany.
Transport (~20% of total primary energy): biomass or biofuels plays only a very small role in transportation, about 2% or 600 TWh of total energy used for transportation (about 33.000 TWh or 20% of all primary energy). 90% of transport energy comes from refined oil products. Brazil is the leader in global “bioethanol” production primarily from sugarcane. Up to 40% of energy for transportation comes from “bioethanol” in Brazil.
Figure 2: Global Energy Use, Sources: Author based on [10, 11, 13]
In different areas of the world, Biomass is being used in different forms and from different sources. Crops and waste are the most important sources. Here is a summary [3]
Crops
- Energy Crops: Dedicated crops such as switchgrass, miscanthus, and fast-growing trees like poplars and willows are cultivated specifically for bioenergy.
- Wood: This includes firewood, wood chips, and wood pellets from trees grown specifically for that purpose. These are often used for heating, electricity generation, and industrial processes.
Waste
- Organic Waste: This includes municipal solid waste (e.g., food scraps, yard waste), industrial organic waste, and animal manure, which can be converted into biogas or other forms of energy
- Biogenic Materials in Waste: Paper products, cotton, and other biodegradable materials contribute to biomass energy.
- Wood Residues: This includes wood chips, sawdust, and wood pellets from left-over wood processing.
- Agricultural Residues: Materials like straw, corn stalks, sugarcane bagasse, and other crop residues are used for energy production.
Other:
- Algae: Certain types of algae are used to produce biofuels, such as biodiesel and bioethanol.
Clearly, biomass from waste or residues should be the focus, and often – but not always – is when municipalities “burn” biomass.
But it appears that wood use for energy, including for residential heating, comprises about 50% of total wood use, according to Eurostat data [4].
The movie “Planet of the Humans” by Michael Moore available on YouTube has drawn 15 Mln viewers and is an excellent way to get “introduced to the biomass industry”.
3. Global greening
Before we address the environmental impact of large-scale biomass production for energy purposes, let’s look at how the world is doing in terms of plant and wood coverage.
When you look at history books and maps, you will see that Europe, China, and later parts of North America where nearly void of trees as the growing population chopped down, burnt, and built with virtually every tree to be found nearby. This was because there was no additional source of energy yet. Today, of course, specific crops are grown as a source for biomass and replanting of trees and forests is at the forefront of environmental protection. Somehow, us humans managed to replant a large portion of the woods lost during the past centuries.
I just came back from a few days in the Swiss “Appenzell” where I saw 200 and 300-year-old paintings showing the valley of the town of “Speicher” near St. Gallen completely void of trees, all “harvested” for building materials and energy. Today, the land had largely recovered with trees and forests covering the hills around the town Speicher.
It is interesting that the world today is the greenest it has been since the start of satellite recording and probably in centuries (Figure 2) due to,
- (a) increasing CO2 concentrations,
- (b) slightly warmer temperatures, and
- (c) human fertilization and planting,
even though the utilization of biomass for energy continues to increase.
This 4-decade long greening, due to an increase in leaves on plants and trees, covers an area roughly two times the continental United States. Results show that increased carbon dioxide concentrations explains 70 percent of the greening effect through “CO2-fertilization” [NASA 5]. Ranga Myneni, a professor in the Department of Earth and Environment at Boston University said “The second most important driver is nitrogen, at 9 percent. So we see what an outsized role CO2 plays in this process.”
Global CO2 fertilization and its positive impact on greening and crop yields has been confirmed in numerous scientific peer-reviewed papers from all over the world, for those interested, here is an incomplete list:
- McKitrick 2025: Extended Crop Yield Meta-Analysis Data Do Not Support Upward SCC Revision, Scientific Reports 15, no. 1 (February 2025): 5575. https://doi.org/10.1038/s41598-025-90254-2.
- Lai et al 2024: Terrestrial Photosynthesis Inferred from Plant Carbonyl Sulfide Uptake, Nature 634, no. 8035 (October 2024): 855–61. https://doi.org/10.1038/s41586-024-08050-3.
- Chen et al 2024: The Global Greening Continues despite Increased Drought Stress since 2000, Global Ecology and Conservation 49 (January 2024): e02791. https://doi.org/10.1016/j.gecco.2023.e02791.
- Li et al 2024: Vegetation Greenness in 2023, Nature Reviews Earth & Environment 5, no. 4 (April 2024): 241–43. https://doi.org/10.1038/s43017-024-00543-z
- Haverd et al 2020: Higher than Expected CO2 Fertilization Inferred from Leaf to Global Observations, Global Change Biology 26, no. 4 (February 2020): 2390–2402. https://doi.org/10.1111/gcb.14950
- Piao et al 2020: Greening, Characteristics, Drivers and Feedbacks of Global Greening, Nature Reviews Earth & Environment 1, no. 1 (January 2020): 14–27. https://doi.org/10.1038/s43017-019-0001-x
- Kucharik & Ramankutty 2005, Trends and Variability in U.S. Corn Yields Over the Twentieth Century, Earth Interactions 9, no. 1 (March 2005): 1–29. https://doi.org/10.1175/EI098.1.
- Qiao et al 2019: Elevated CO2 and Temperature Increase Grain Oil Concentration but Their Impacts on Grain Yield Differ between Soybean and Maize Grown in a Temperate Region, Science of The Total Environment 666 (May 2019): 405–13. https://doi.org/10.1016/j.scitotenv.2019.02.149
- Zhu et al 2016: Greening of the Earth and Its Drivers, Nature Climate Change 6, no. 8 (August 2016): 791–95. https://doi.org/10.1038/nclimate3004.
- Idso, Craig D. Plant Growth Database: CO2 Science, http://www.co2science.org/data/plant_growth/plantgrowth.php.
Figure 3: Satellite measured greening Source: Nasa [5]
4. Greenhouse gases and environmental impact of biomass
The idea that burning “grown” biomass for energy purposes as being “emission neutral” is in serious dispute. Various studies have clarified that “Burning trees for energy is not a climate solution” [6]. The reason why it doesn’t make sense is relatively simple as explained by the Institute for Governance & Sustainable Development:
- Burning woody biomass releases more carbon dioxide (CO2) per unit of energy than fossil fuels, including coal plus an array of particulate emissions.
- It takes many decades for tree regrowth to offset those emissions.
- Also, relying on tree regrowth ignores the damage to natural forests from harvest – both to forests’ carbon sink capacity and biodiversity.
American journalist and author, Michael Grunwald writes in the New York Times, “as America rushes to generate more renewable electricity, it has become fashionable to fret that solar and wind farms use too much land. But America is also racing to produce more renewable fuels, and they use much, much more land to displace much, much less fossil fuel.
It’s fairly well-known that farm-grown fuels like corn ethanol and soy biodiesel, not only accelerate food inflation and global hunger, but they are also disastrous for the climate and the environment… mainly because they are inefficient land hogs.
It takes about 100 hectares worth of biofuels to generate the same amount of energy as a single hectare of solar panels worldwide (not that you can compare intermittent power with dispatchable power). In the US, a land mass larger than California was used to grow under 4% of transportation fuel in 2020, resulting in a huge waste of precious land the world needs to store carbon that can stabilize our warming climate and grow crops that can help feed the growing population.”
The US Environmental Protection Agency (EPA) could help rein in the waste if it updates America’s sweeping mandate encouraging biofuel production, but it probably won’t, though, because in Washington, where cornethanolism is one of the last truly bipartisan ideologies, nearly everyone loves to pretend biofuels are “green”.
- The EPA website states [7] “Biofuel production and use has drawbacks as well, including land and water resource requirements, air and ground water pollution. Depending on the feedstock and production process, biofuels can emit even more GHGs than some fossil fuels on an energy -equivalent basis.”
What makes corn-based ethanol distinct from most of our other wasteful agricultural giveaways, is that it diverts crops from bellies to fuel tanks and uses almost as much fossil fuel, from fertilizers made of natural gas to diesel tractors, industrial refineries and other sources, as the ethanol replaces.
But the more interesting negative effect of biofuels, first revealed in a 2008 paper in the journal Science, is that they increase GHG emissions through the conversion of carbon-rich forests, wetlands and grasslands into farmland, expanding our agricultural footprint while shrinking nature’s.
By 2050, the world will need to grow an additional 7.4 quadrillion calories every year to fill nearly 10 billion bellies, while reducing deforestation and other wilderness destruction to meet environmental targets. Biomass use for energy purposes, makes both jobs much harder.
Furthermore, consider that every forest fire (wood) is labeled a “climate catastrophe,” yet burning wood in power plants is supposedly “no problem at all.”
My take: The green-climate lobby has had its way for a while now in the US and globally, and it’s got conspicuously little to show for its efforts. One reason is the advocacy for non-solutions like using biomass (other than waste products) for energy purposes. Until our decision-makers have the courage to face the truth, we’ll continue down dual paths of wasteful spending and little progress in reducing our environmental footprint.
Case in point: the Drax biomass power plant in the UK [8 and 4]
- Completed in 1986, it was the newest coal fired power station in the UK until it closed and was converted to biomass in 2021. In 2010 it already started co-firing biomass.
- The FTSE 100 owner of the Drax power plant made profits of £500m over the first half of 2024, helped by biomass subsidies of almost £400m over this period.
- The Drax power station is the single largest “CO2 emitter” of the UK, still… in 2023, when Ratcliffe was still burning coal (2GW), the Drax “green” biomass power station (2,6GW) emitted 4x more CO2 than Ratcliffe
- The total subsidy amount since coal-to-biomass conversion exceeds £6 billion, making Drax one of the most heavily subsidized energy producers in the UK.
- Drax sources 9 mln tons of biomass p.a., 8 mln come from the US and Canada by vessel. Of course, the biomass needs to be processed to wood pellets first, before being transported to the UK, requiring additional energy that is usually not considered.
Declaring that biofuels are CO2 -neutral as the EU and others have done, erroneously assumes forest regrowth quickly and fully offsets the emissions from biofuel production and combustion. The neutrality assumption is not valid because it ignores the transient, but decades to centuries long, increase in CO2 caused by biofuels. [see Sterman et al, 9]
Figure 4: Does replacing coal with wood lower CO2 emissions? Source: IOP Science
5. Summary
Biomass has been part of humanity’s energy story for thousands of years. Today, it still plays a role, making up about 9% of the world’s primary energy supply. That sounds small, but in absolute terms, we use more biomass now than during the early industrial era, hundreds of years ago.
Supporters of biomass call it “green” and “renewable,” because the carbon dioxide it releases during combustion is considered part of a natural cycle… therefore it is expected to contribute to “saving the climate”.
But when you dig deeper, the picture gets more complicated. Biomass is not necessarily sustainable. Crops grown for energy, like corn for ethanol or soy for biodiesel, take up massive amounts of land, often at the cost of forests or food production. And the energy returns can be low once you factor in everything from fertilizer to fuel for machinery, processing, and transportation. Burning trees for electricity provenly emits more CO2 than burning coal per unit of energy… which is not offset for decades if at all.
I expressively support the use of biogenic or biomass waste products, that would otherwise go on landfills, to be used for energy “production”. However, I only support waste use if the useful energy made available from such waste supersedes by a multiple the energy it takes to “make the waste into energy” using a full life cycle analysis (see eROI concept). Because we don’t only have top consider the energy it takes to utilize waste but also the raw materials, machinery, and human as well as financial resources.
There’s also a twist in the story…the planet has actually gotten greener over the past few decades. Thanks to higher CO₂ levels, warmer temperatures, and human replanting, satellite data shows a surge in plant growth globally, mainly due to a “CO₂ fertilization” effect. So yes, more leaves, more green.
My blog post challenges the narrative that biofuels are a smart climate solution. I argue that land is wasted, driving food inflation, and often ends up emitting as much (or more) carbon dioxide than it saves.
The net energy efficiency of converting biomass to electricity is extremely low.
My conclusion… if policymakers are serious about reducing environmental impact of our energy systems, they need to rethink the heavy push for biofuels and face the hard truths about land, energy, and environmental trade-offs.
Links and Resources
[1] Simpson et al 2024: Observed Humidity Trends in Dry Regions Contradict Climate Models.” Proceedings of the National Academy of Sciences 121, no. 1 (January 2024): e2302480120. link
[2] Coe et al 2021: The Impact of CO2, H2O and Other ‘Greenhouse Gases’ on Equilibrium Earth Temperatures.” International Journal of Atmospheric and Oceanic Sciences 5, no. 2 (August 2021): 29. link
[3] World Bioenergy Association WBA, link
[4] PFPI 2020 link and ClimateEarth link
[5] NASA on Greening link
[6] Bloomer et al 2022: Call to Stop Burning Trees in the Name of Climate Mitigation.” VERMONT JOURNAL OF ENVIRONMENTAL LAW 23 (n.d.) link
[7] EPA Environmental Protection Agency, USA link
[8] Ember The largest emitters in the UK: annual review | Ember link and Gardian on DRAX, Aug 2024, Biomass power station produced four times emissions of UK coal plant- the Guardian link
[9] Sterman et al 2018: Does Replacing Coal with Wood Lower CO2 Emissions? Dynamic Lifecycle Analysis of Wood Bioenergy, Environmental Research Letters 13, no. 1 (January 2018): 015007. link
[10] Our World in Data link
[11] BP Energy Outlook link
[13] Eurostat – Renewable Energy Statistics link
[14] Ember’s Global Electricity Review link
[15] Statista link
[16] World Energy Council link
[17] McKinsey Global Energy Perspective link
[18] European Biogas Association’s Gasification Report (2024), link