Carbon Loophole: Why Is Wood Burning Counted as Green Energy?

By Fred Pearce. He is a contributing writer for Yale Environment 360. Excerpts:

"It was once one of Europe’s largest coal-burning power stations. Now, after replacing coal in its boilers with wood pellets shipped from the U.S. South, the Drax Power Station in Britain claims to be the largest carbon-saving project in Europe. About 23 million tons of carbon dioxide goes up its stacks each year. But because new trees will be planted in the cut forests, the company says the Drax plant is carbon-neutral.

There is one problem. Ecologists say that the claims of carbon neutrality, which are accepted by the European Union and the British government, do not stand up to scrutiny. The forests of North Carolina, Louisiana, and Mississippi — as well as those in Europe — are being destroyed to sustain a European fantasy about renewable energy. And with many power plants in Europe and elsewhere starting to replace coal with wood, the question of who is right is becoming ever more important.

Since 2009, the 28 nations of the European Union have embarked on a dramatic switch to generating power from renewable energy. While most of the good-news headlines have been about the rise of wind and solar, much of the new “green” power has actually come from burning wood in converted coal power stations.

Wood burning is booming from Britain to Romania. Much of the timber is sourced locally, which is raising serious concerns among European environmentalists about whether every tree cut down for burning is truly replaced by a new one. But Drax’s giant wood-burning boilers are fueled almost entirely by 6.5 million tons of wood pellets shipped annually across the Atlantic. 

In September, some 200 scientists wrote to the EU insisting that “bioenergy [from forest biomass] is not carbon-neutral” and calling for tighter rules to protect forests and their carbon. Yet just a month later, EU ministers rubber-stamped the existing carbon accounting rules, reaffirming that the burning of wood pellets is renewable energy.

Under the terms of both the UN Paris climate agreement and Europe’s internal rules, carbon losses from forests supplying power stations should be declared as changes to the carbon storage capacity of forest landscapes. But such changes are seldom reported in national inventories. And there is no system either within the EU or at the UN for reporting actual changes in carbon stocks on land, so the carbon is not accounted for at either end — when trees are cut, or when the wood is burned."

"The debate is not clear-cut. Burning wood may be close to carbon neutral in some situations, such as where it is clear that cut trees are replaced with the same trees, one for one; but in others it can emit even more carbon than coal. The trouble is that regulators are ill-placed to tell the difference, which will only be clear decades after the presumed emissions have been tallied — or not — in national carbon inventories.

The one certainty is that if things do not go according to plan, Europe’s promises for meeting its Paris climate commitments will go up in smoke. And the U.S.’s own CO2 emissions could resume their upward path even quicker than President Donald Trump intends."

"Roughly half the cut wood in the EU is now being burned to generate electricity or for heating. And there is growing evidence that the logging is damaging forests and reducing their ability to store carbon.

One region at risk is the Carpathian Mountains, stretching from Austria to Romania. It contains the continent’s largest surviving old-growth forests outside Russia, which are home to up to half the continent’s brown bears, wolves, and lynx."

"On a visit to the region, I saw strong evidence of a threat to forests in eastern Slovakia, where there was widespread felling of beech forests inside the Poloniny National Park. The roads to the park were all being widened, using EU infrastructure funds, to improve access for heavy vehicles that bring out the timber."

"10 million cubic meters of wood is logged in the country each year, against a sustainable yield of 6 million cubic meters. The difference is almost entirely accounted for by the 3.5 million cubic metres burned for Slovakia’s energy and heating. Yet nowhere do the carbon emissions from this burning turn up in the carbon accounts of Slovakia or the EU."

"an EU report last year forecast that the growth of Europe’s forest sink will be reduced by more than 30 percent between 2005 and 2030 because of cutting for pellet burning and other changes in land use. It said that “biomass and land use change can be identified as key drivers” in the predicted decline, with pellet-burning plants clearly playing a large part. Yet so far, the resulting releases of carbon to the atmosphere are not included in EU carbon accounting."



"Following conversion of its boilers, two-thirds of the power from the 4,000-megawatt power giant on the east coast of England now comes from burning pellets. The pellets mostly come from three American mills run by the Drax Group — at Amite in Mississippi, and Morehouse and LaSalle in Louisiana — and purchases from other U.S. suppliers, notably Enviva, which has in the process become the world’s largest producer of wood pellets.

Drax says the only carbon footprint from burning those pellets is from the harvesting, processing, and transporting of the wood. It reckons that, overall, converting its power plant from coal to wood saves 12 million tons of CO2 emissions a year, making Drax “the largest carbon-saving project in Europe,” according to its CEO Andy Koss. 

The EU and the U.K. both accept that analysis. The British government last year gave the company the equivalent of about $720 million in subsidies to make further conversions to burning wood so as to reduce the country’s carbon emissions in line with the 2015 Paris climate agreement."

"But critics say there are a series of problems with the claim. The first is that nobody can be certain the new trees necessary to absorb power-station emissions will ever be planted, especially since Drax does not own the forests harvested for its timber. A British government study in 2014 concluded that a worst-case scenario, in which the logged forest land is turned over to agriculture, could result in total CO2 emissions twice as great as from burning coal."

"Even if new trees are planted promptly to replace old ones, they will take between 20 and 100 years to grow sufficiently to take up all the CO2 emitted by burning the old trees. Throughout that time, there will be more CO2 in the air."

"wood cut for construction or making furniture will keep its carbon out of the atmosphere for much longer than wood cut to burn in a power station."

"A third concern is exactly which bits of the trees are burned at the power station. Do their boilers run on specially cut timber or waste wood? Most operators of wood-burning power plants publicly insist that their main fuel is forest “thinnings,” such as twigs and branches. But in practice, the definition of “thinnings” often includes whole trees. In fact, it is often mostly whole trees."

"most wood pellets produced in the U.S., both for domestic burning and for export to the U.K., were prepared from whole trees.

The issue is critical because leftovers from harvested trees, such as twigs and branches, would typically be burned in wood mills as waste, or left to rot on the forest floor. They would quickly release their carbon. All agree that burning them for electricity generation would not add to atmospheric CO2, whereas whole trees left standing would continue to grow and absorb CO2 from the air.

Forests are not just carbon stores, of course. They are also functioning ecosystems that could be wrecked by logging to supply pellets. Here concern has centred less on the yellow pine forests that supply Drax’s own pellet mill, and more on the forests of North Carolina and Virginia that supply its biggest outside supplier, Enviva. These often contain hardwoods such as oak and sweetgum."