31. Biomass Revisited

 Biomass Revisited

Our recent column “Is Biomass a Climate Solution?” generated some feedback from members of the biomass industry in Maine. We greatly appreciate feedback, so we would like to respond.

To review the column’s content, our main point was that using wood pellets from mature trees in place of oil or gas is not going to budge the global warming needle. If curbing greenhouse gas emissions drastically and expeditiously is our mission, switching to another combustion fuel is not better enough.

We made a distinction between what is happening in North Carolina, the annual clear-cut of 60,000 acres to be pelletized and sent to the E.U. for biomass to meet their “renewables” quotas, and what the Maine biomass industry comprises.

Perhaps we didn’t make this point clearly enough, and thereby regrettably offended some Maine biomass proponents. However, our thesis still stands: biomass burning as it is being employed by E.U. countries to meet their greenhouse gas reduction calculus is NOT a climate solution.

We did not say that burning wood pellets made from waste wood in Maine isn’t an improvement over burning fossil fuels - just that it isn’t actually a policy solution with significant promise, if the goal is to cut emissions fast enough to avoid catastrophic and uncontrollable climate chaos.

What is going on in North Carolina is worse than using coal. What Maine is doing now is fine but has limited growth possibilities, simply based on the rate at which biomass regenerates. It is limited by the natural process of photosynthesis. Period. 

In a recent Op Ed in the Norway Advertiser Democrat, the authors maintain that we are focusing our attention on questioning a “proven and critical piece of any solution to [the climate] issue.”

We have not found that biomass is a proven or critical piece of a pathway to carbon neutrality. Physico-economic modeling such as the MIT/Sloane’s “En-ROADS” demonstrates that shifting to more biomass energy would have little impact on the temperature increase over the next 80 years. 

As for “proven,” with the 1997 Kyoto protocol the UN basically made an error with its blanket declaration that biomass burning is net carbon neutral, failing to consider the necessary 60-100 year regrowth time frame (or even to mandate replanting). Some countries in the E.U. have exploited this error and are burning biomass harvested from Canada, the U.S., and some of the poorer European countries such as Latvia and Lithuania where old-growth forests are being clear-cut for biomass energy. Most are not being replanted. 

Meanwhile the CO2 from that burning is going into the atmosphere at a rate greater than coal burning. The EU leadership is now recognizing that they need to revisit the question of the viability of biomass.

The Op-Ed also pointed out that “According to the IPCC, every pathway to keeping temperature increases under 1.5 degrees Celsius includes sustainable forestry and wood biomass.” The key here is “sustainable.” Cutting mature forests and turning them into wood pellets, shipping them around the world, and burning them for fuel is not sustainable in the timeframe humanity is facing.

And as we stated, our understanding is that Maine’s current rates of harvest and burning are essentially in balance. We are not sure why our critics are protesting our objection to practices they are not engaging in at present.

The piece goes on to say that the “EU and the United Kingdom are vigorously pursuing biomass energy as part of their region’s climate solution,” and criticize the U.S. for being slow to follow. Right - the EU’s approach to the pursuit of biomass has been to get North Carolina and other southeastern U.S. states to seriously exploit their forests and harvest at a completely unsustainable rate. Germany and the UK and Japan are not cutting their own forests at this rate—They are instead taking ours, taking advantage of an error on the part of the IPCC and essentially cheating on CO2 emissions accounting.

We know the Maine biomass industry has no intention of doing in Maine what is going on in North Carolina. However there is still cause for concern. While we do not know the precise limits to which the Maine pellet industry can grow, it clearly can never provide enough heat to grow beyond a limited amount, due to time and space limitations.Years ago Dick Hill, long-time energy commentator from U Maine, estimated that to heat Maine with wood would take more than the area of the entire state. 

Another point made is that by substituting wood pellets for heating oil in oil dependent Maine households, we could greatly reduce the household heating carbon emissions. While we believe pellets may well play a role, a more efficient approach is to install more heat pumps. A heat pump delivers more Btu’s per dollar and less CO2 per Btu than pellets regardless of electricity source. Air source heat pumps in Maine typically require a supplemental source of heat for the coldest days.This is when pellet heating could play a useful role.

Another industry representative claimed we misunderstand the science of wood. He states that the amount of CO2 from burning wood is the same as would be produced by letting it decompose in the forest. Actually, some decomposing material is necessary to maintain the carbon content of the soil, and if the slash is removed for pellets or other combustion, over time the carbon (and other nutrients such as nitrogen) sequestered in the soil will decrease.

We also need to consider the time frame over which the CO2 goes into the atmosphere. In the decay process the larger pieces of material can take many years to release their CO2, while burning releases it immediately. Right now we are concerned with decreasing the rate at which CO2 is being released in the short term.

We have no argument with using sawdust, utility trimming, or municipal green waste for pellets. These are wood waste that would otherwise decompose quickly anyway (although they could be buried for long term sequestration.) . The concern is that over time, increased demand for pellet fuel will incentivize more harvesting just for pellets. This could either push us in the direction of North Carolina or leave pellet-burning facilities with stranded assets as the fuel supply becomes insufficient. 

In the end, it seems that using our wood pellet industry judiciously to the benefit of Mainers as we transition to minimal carbon emissions, and keeping it truly sustainable, is a goal we can all agree on.

Paul Stancioff, PhD., is a professor of Physics at the University of Maine Farmington. Cynthia Stancioff is an observer of nature, including human, who can’t stop editing her own and other people’s writing. Their emails are pauls@maine.edu and cynthia.hoeh@gmail.com .