As European countries, for the large part, turn away from coal, burning wood is increasingly being presented as a renewable and environmentally friendly alternative. Yet wood-based bioenergy is far from carbon neutral and its production has grave consequences for land use and ecosystems around the world.

In February 2016, Danish energy firm DONG Energy – now called Ørsted – announced that it would stop burning coal by 2023. DONG used to be one of the most coal-intensive energy companies in Europe and, less than ten years ago, was pushing plans to build new coal plants in Scotland and Germany, abandoned only after large protests in both countries. So has the company now turned into a climate hero, setting an example for others to follow?

A coal phase-out across – and beyond – Europe is long overdue. An analysis of different carbon budgets presented by the International Panel on Climate Change in 2014 shows that, if global CO2 emissions were to remain the same as in 2016, the window for limiting global warming to 1.5 degrees Celsius will close around 2021. Burning coal emits more CO2 per unit of energy than burning any other fossil fuel, so even a 2023 phase-out is far slower than what is needed. Yet it is seven years sooner than the coal phase-out required by the Danish government, and ahead of similar commitments by any other government in coal-burning European countries. 

While an end to coal burning cannot come soon enough, the question is: what replaces it? To avoid the worst consequences of climate change, we need to stop burning fossil fuels as quickly as possible, protect our natural ecosystems and soils, allow forests and other ecosystems that have been damaged or destroyed to regenerate, and actively restore biodiverse ecosystems them where necessary. Otherwise, stabilising the climate at 2 degrees of warming, let alone 1.5, will simply not be possible.

Replacing coal with other carbon

Ørsted has chosen two options for replacing coal. On the one hand, it has become a global leader in offshore wind, with projects in Denmark, the United Kingdom, Germany, the Netherlands, the United States, and Taiwan. Offshore wind is indisputably a very low-carbon form of energy, even when life-cycle emissions that include for example carbon released during steel making are accounted for. On the other hand, the company has chosen to convert six coal plants and another one burning gas to run on biomass, mostly wood pellets. This choice, which is mirrored in the decisions of several other energy companies around Europe, depends on governments allowing companies to class bioenergy as ‘carbon neutral’ or at least ‘low carbon’. In reality, the use of wood-based bioenergy is far from compatible with any hope of stabilising the climate.

The ‘carbon neutral’ biomass myths

The idea that burning wood is carbon neutral has always seemed counter-intuitive to me. Burning biomass releases CO2 just the same as burning fossil fuels does, and every molecule of carbon released in the atmosphere contributes to global warming, no matter its source. In fact, generating a unit of energy from burning wood emits even more CO2 than from coal because it is less efficient. For decades we have heard that growing trees is good for the climate. How has the idea that cutting them down and burning them is climate friendly or ‘zero carbon’ gained such traction? 

Firstly, burning wood is widely regarded as ‘natural’ and thus innocuous. After all, our ancestors were burning wood for cooking and heat as long as a million years ago. However, historical evidence shows that excessive wood demand already caused widespread deforestation thousands of years ago. During the 1630s, England became the first country in the world to use more coal than wood for fuel, an energy transition driven to a large part by wood shortages. Landowners tried to address those shortages through a strict system of traditional coppicing, a more sustainable practice than much of what is today called ‘sustainable forest management’. But they simply could not produce enough wood for metal smelting as well as meeting households’ energy needs. Using wood as a fuel, especially for smelting, caused even larger scale deforestation elsewhere. In colonial Mexico, charcoal making for silver smelting destroyed an estimated 40 million hectares of rainforest during the 16th century. Whether human activities pre-1750 were significant enough to affect the global climate is a matter of debate. Some scientists argue that anthropogenic greenhouse gas emissions may already have been large enough in the pre-fossil fuel age to have staved off cyclical global cooling, before spiking after the industrial revolution and causing disastrous warming. 

In fact, generating a unit of energy from burning wood emits even more CO2 than from coal because it is less efficient.

The second, more pragmatic, reason why bioenergy is classed as carbon neutral goes back to the early negotiations around international greenhouse gas reporting and accounting. Delegates decided that, if trees were cut down or lands converted for bioenergy, the loss of carbon which had previously been sequestered in forests, soils, and other ecosystems would be attributed to the land use and forestry sector in the country where the logging or land conversion took place. They wanted to avoid ‘double counting’ of bioenergy emissions by not also attributing them to energy companies burning biomass. This would make perfect sense if the sole aim was to come up with a good estimate of global greenhouse gas emissions. But as carbon accounting rules inform energy policies around the world, it creates what scientists have called a serious carbon accounting error. It allows energy companies to burn woodchips and pellets made from trees cut down anywhere in the world, without having to account for the impact on the climate.

Because bioenergy is classed as zero carbon, many governments generously subsidise wood burning as a quick fix for ‘decarbonising’ their energy sector. In Denmark, for example, companies do not have to pay tax on heat supplied from biomass, even though they are taxed on the supply of electricity from wind (even when used for electric heating). There are few incentives to reduce overall emissions from logging or converting forests to tree plantations either. Under current United Nations Framework Convention on Climate Change rules, emissions from land use and forestry are compared not to emissions in previous years but to ‘business as usual baselines’ drawn up by governments. These baselines allow countries to greatly increase emissions in this sector and nonetheless be able to present them as reductions. These accounting practices have proved very convenient: EU countries effectively outsource very real carbon emissions to countries such as the United States and Russia, which, in turn, do not properly account for them either. As far as EU-sourced biomass is concerned, new regulations offer a slight improvement as far as carbon accounting from land use and forestry are concerned, but those changes are severely undermined by EU and Member State policies promoting expansion of wood-based bioenergy.

The third reason why bioenergy is so attractive is an economic one: replacing, or complementing fossil fuel burning with biomass requires only limited infrastructure changes. An energy company may have to invest a substantial sum to convert a coal power station to biomass. But the power station will nevertheless remain an ‘asset’ rather than being written off, which is important for share prices. Some energy companies, such as the United Kingdom firm Drax, which runs a major coal plant in North Yorkshire that has been converted to burn mainly biomass, are establishing themselves as major wood pellet traders as well as producers. Trading allows these firms to cash in regardless of whether pellet prices rise or fall. And companies which have long imported coal benefit from close relations with ports and the shipping industry, replacing coal terminals with biomass silos. Biomass heating, meanwhile, helps to perpetuate the reliance on combustion, as opposed to electrification coupled with an expansion of no-burn renewable energy, something that would require very major changes to infrastructure. And across all sectors, the myth of abundant carbon neutral bioenergy distracts people from the need to greatly reduce energy use across Europe. Significant reductions in total energy use are vital for the climate, but they threaten economic growth.

Because bioenergy is classed as zero carbon, many governments generously subsidise wood burning as a quick fix for ‘decarbonising’ their energy sector.

None of the reasons why burning wood is regarded as carbon neutral are scientific ones. Indeed, a large and growing volume of scientific studies shows that it is anything but zero carbon, especially when trees are cut down for this purpose. 800 scientists recently warned the European Parliament: “Even if forests are allowed to regrow, using wood deliberately harvested for burning will increase carbon in the atmosphere and warming for decades to centuries – as many studies have shown – even when wood replaces coal, oil or natural gas. The reasons are fundamental and occur regardless of whether forest management is ‘sustainable.’” 

Claims that power plants simply burn wood ‘residues’ (by-products of tree felling and timber processing) are spurious. Pictures of pellet plants and woodchip mills supplying biomass for energy routinely show huge piles of logs. Russia’s biggest pellet plant, Vyborgskaya, which sells pellets t in Scandinavia, including to Denmark, has been described as “the largest wood-yard in Europe” by industry. This is not surprising: there simply are not enough genuine residues to replace a significant amount of coal with wood. Denmark, for example, burns more than half of the wood it produces every year, and imports far more than its annual wood production as pellets. In the UK, Drax power station, which has now been over 50 per cent converted to wood pellets, burns 1.2 times the country’s annual wood production, for which it is handed 2 million pounds (2.25 million euros) in subsidies per day. Burning all of that wood generates less than 0.8 per cent of the UK’s energy demand.

The global impact of wood burning

Lessons from history have been forgotten: if 16th century England could not meet its limited energy demand from wood without depleting its forests, then how can we possibly expect to replace coal with wood and not see huge swathes of forests cut down and converted to industrial tree plantations? As environmental historian Paul Warde pointed out in 2007, prior to the fossil-fuelled industrial revolution, Western Europeans used 10-20 gigajoules of energy per year. Today, Europe’s annual per capita annual energy use is around 200 gigajoules, and the continent has a population three times larger than two centuries ago. Replacing a substantial fraction of fossil fuels with biomass is simply not possible without sacrificing land and forests on a vast scale.

Climate change has escalated well beyond the stage where we can afford ‘transitional solutions’ which replace coal with another high-carbon source of energy

More monoculture tree plantations for bioenergy will only compound the problem. In the southern United States, the world’s biggest pellet producing region, millions of hectares of rich forest ecosystems have been converted to monoculture pine plantations, yet this loss of once vast biodiverse forest ecosystems is not classified as deforestation. Vital habitats for animals and plants are being destroyed in the process, large amounts of carbon lost to the atmosphere, and forests which help regulate rainfall and protect watersheds, and thus prevent drought and floods, are replaced with monocultures. At the same time, soils are depleted rather than replenished. Elsewhere, for example in South Africa, tree plantations replace highly biodiverse and carbon-rich grasslands, and across the global South, tree plantations drive small farmers and other communities off their land, depriving them of their ability to produce food and of their homes and livelihoods.

A way forward without biomass

What can be done to make sure that coal burning is stopped and not replaced with another form of energy that also makes climate change worse? As far as the electricity sector is concerned, the UK sets an interesting example. Between 2011 and 2016, the UK’s coal use for electricity fell by 72 per cent, and it has dropped further since. Even though the UK is the world’s biggest pellet importer and user, the decline in coal was primarily compensated for by a trebling of wind and solar power, plus a fall in electricity use thanks to greater efficiency (a trend sadly cut short due to government attacks on onshore wind, solar, and home insulation). Across the EU, no-burn renewables compensated 2.6 times over for the fall in coal electricity between 2000 and 2015. And they would be doing better still if they did not have to compete with bioenergy for subsidies.

In Denmark, unfortunately, the situation is more complicated, ironically due to a successful past campaign to connect fossil fuel power stations to district heating networks. Industry and policymakers call biomass a transitional solution only. Yet the huge investments first into district heating and now into biomass conversions leave little incentive to do away with this infrastructure and instead to rapidly roll out wind-powered electric heating, including with heat pumps or even solar power, while at the same time retrofitting houses so less heat is needed. Instead, homes previously heated with coal are now heated through cutting down and burning trees, with no benefit to the climate.

Climate change has escalated well beyond the stage where we can afford ‘transitional solutions’ which replace coal with another high-carbon source of energy, be it biomass or fossil fuel gas. We absolutely need a rapid coal phase-out, but one which is part of a holistic transition to both a low-energy and a truly low-carbon society.

Sadly, the EU is set to adopt a new Renewable Energy Directive post-2020, which the EU Parliament has endorsed, supporting further destructive, high-carbon burning of wood for energy, in flagrant disregard of warnings by scientists. However, it is and will remain within the power of individual EU Member States to decide how they will meet their renewable energy targets, namely whether they want to focus support entirely on no-burn renewable energy or to a large extent on bioenergy. Member States can and must stop biomass subsidies and shift them to supporting truly low-energy renewables and measures to reduce energy use.

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