KEF, Alm.del - 2020-21 - Bilag 52: Henvendelse af 2/11-20 fra Jan Mayland om brugen af biomasse og den positive indflydelse på CO2-optaget

Klima-, Energi- og Forsyningsudvalget 2020-21
KEF Alm.del Bilag 52
Offentligt

The use of forest biomass for climate change

mitigation: dispelling some misconceptions

IEA Bioenergy, August 2020

Recent articles and statements in the media

and

raise concerns over the climate effects of using

forest biomass for bioenergy. As some statements seem to reflect misconceptions about forest

bioenergy, IEA Bioenergy here provides a brief overview of key facts about the use of forest biomass

for climate change mitigation.

1. Forest bioenergy is not by definition carbon neutral; emissions in the supply chain and impacts

on forest carbon stock must be included.

Bioenergy is sometimes said to be “carbon neutral” in the sense that the carbon that is released

during combustion (biogenic carbon emissions) has previously been sequestered from the

atmosphere and will be sequestered again as the plants regrow. But “carbon neutrality” is an

unhelpful term because it is ambiguous and used differently in different contexts. As is further

elaborated below, biogenic carbon needs to be considered in assessments in order to fully reflect

how bioenergy will affect atmospheric GHG concentrations. If extraction of biomass for energy leads

to a decline in the forest carbon stock or carbon sink strength, this needs to be accounted for.

Furthermore, assessments need to consider all emissions associated with the production, processing,

transport and use of bioenergy. Finally, the bioenergy scenario should be compared with a

counterfactual scenario, in which energy is provided by another source, to quantify the net effect on

GHG emissions.

2. Forest biomass is not treated as carbon neutral in national greenhouse gas inventories.

The treatment of bioenergy in greenhouse gas inventories has been criticized for containing a

loophole because bioenergy is “counted as carbon neutral”. This is incorrect. Under the agreed

approach for preparation of national greenhouse gas inventories, countries report harvest of forests

for any purpose, including bioenergy, as a CO

emission in the land use sector

. CO

emissions from

combustion of biomass for energy are not counted in the energy sector to avoid double counting

with the land use sector. Thus, there is no accounting error that requires correction, or emission that

For example: BBC News 23.02.2017 “Most energy schemes are a ‘disaster’ for climate change”; EASAC press

release 10.09.2019 “EASAC's Environmental Experts call for international action to restrict climate-damaging

forest bioenergy schemes” ; The Guardian 16.12.2019 “Converting coal plants to biomass could fuel climate

crisis, scientists warn”; EASAC press release 26.08.2020 “Emissions Trading System: Stop Perverse Climate

Impact of Biomass by Radically Reforming CO2 Accounting Rules”

For example:

Brack, D., 2017. Woody biomass for power and heat: Impacts on the global climate.

Environment, Energy and Resources Department, Chatham House. ; Searchinger, T.D., Beringer, T., Holtsmark,

B., Kammen, D.M., Lambin, E.F., Lucht, W., Raven, P. and van Ypersele, J.P., 2018. Europe’s renewable energy

directive poised to harm global forests.

Nature communications, 9(1),

pp.1-4. ;

Sterman, J.D., et al., 2018. Does

replacing coal with wood lower CO2 emissions? Dynamic lifecycle analysis of wood bioenergy. Environmental

Research Letters, 13(1), p.015007. ; Norton, M.et al., 2019. Serious mismatches continue between science and

policy in forest bioenergy. GCB Bioenergy, 11(11), pp.1256-1263.

UNFCCC reporting sectors Agriculture, Forestry and Other Land Use (AFOLU), formerly Land use, Land-use

change and Forestry (LULUCF) sector.

KEF, Alm.del - 2020-21 - Bilag 52: Henvendelse af 2/11-20 fra Jan Mayland om brugen af biomasse og den positive indflydelse på CO2-optaget

is overlooked in reporting, and bioenergy is not assumed to be carbon neutral: if bioenergy leads to a

reduction (or slower growth) in forest carbon stock this is reflected in national inventories

. Fuel use

in the supply chain is counted in the energy sector of the country where the fuel is consumed, as for

all other traded materials including energy carriers.

Where biomass for bioenergy is traded, the importing country reports no emissions, while the

exporting country reports the emissions in the land sector. This convention could be criticised as

supporting “outsourcing” of emissions by the importing country. This issue applies also to off-shore

manufacturing. For instance, a large share of emissions associated with production of goods

consumed in Europe is reported by China, where manufacturing occurs

. The case of biomass

imports for bioenergy is an example where policymakers have recognized and taken action to

address this challenge

. The EU RED II requires that forest biomass is sourced only from locations

where legislation at national/subnational level, or management systems at the forest sourcing area,

ensure that forests are regenerated and that carbon stocks and sink levels in the forest are

maintained or strengthened over the long term

. Specifically concerning EU pellet importation from

the United States, data show that forest carbon stocks in the south-eastern United States (SE US)

where biomass is sourced, are steadily increasing

, and biomass harvests for wood pellets represent

only a small fraction of harvest removals from forests in the SE US

3. Climate effects of using woody biomass cannot be determined at stand level; assessments

need to be made at the landscape (estate) level.

A forest estate is generally managed as a series of stands of different ages, harvested at different

times, to produce a constant supply of wood products. When considered at stand level, much of the

carbon that has been sequestered into the stand as the trees grow is abruptly lost from the stand at

the time of harvest, and is not fully sequestered again until the stand has reached harvest age. Stand-

level assessments that start the accounting when the stand is harvested will, therefore, show upfront

emissions and a delay before forest bioenergy contributes to net reductions in atmospheric CO

particularly in long-rotation forests.

However, across the whole forest estate (landscape), i.e. at the scale that forests are managed,

carbon losses in harvested stands are balanced by carbon gains (growth) in other stands, so the

carbon stock of production forests is roughly stable. The magnitude of the carbon stocks in forest

landscapes depends on biophysical factors such as soil and climate conditions, historic and current

management regimes, and events such as storms, fires and insect outbreaks. To quantify the climate

However, there is incomplete coverage under the Kyoto Protocol because only some countries account for

their GHG emissions in the second (2013- 2020) commitment period. Under the Paris Agreement, commencing

2020, all parties will include the land sector in their national accounting.

E.g. Chen, Q., Löschel, A., Pei, J., Peters, G.P., Xue, J. and Zhao, Z., 2019. Processing trade, foreign outsourcing

and carbon emissions in China. Structural Change and Economic Dynamics, 49, pp.1-12.

6 see EU Renewable Energy Directive II, L 328/97 (point 102), ‘… harvesting in forests is carried out in a

sustainable manner in forests where regeneration is ensured ...’

EU Renewable Energy Directive II, L 328/131-132, Article 29, par. 6-9

Woodall, C. et al. (2015). The U.S. Forest Carbon Accounting Framework: Stocks and Stock Change, 1990-2016.

USDA Forest Service, Newtown Square, PA.

https://www.fs.fed.us/nrs/pubs/gtr/gtr_nrs154.pdf

[November 28,

2019].

Dale, V. et al. (2017). Status and prospects for renewable energy using wood pellets from the southeastern

United States. GCB Bioenergy (2017)

KEF, Alm.del - 2020-21 - Bilag 52: Henvendelse af 2/11-20 fra Jan Mayland om brugen af biomasse og den positive indflydelse på CO2-optaget

effects of harvesting woody biomass for energy and other products, the effect of this harvesting on

the development of carbon stocks at the landscape level needs to be determined.

Landscape-scale assessment can provide a more complete representation of the dynamics of forest

systems, as it integrates the effects of all changes in forest management and harvesting that take

place in response to – experienced or anticipated – bioenergy demand. The landscape approach

therefore helps to identify how total forest carbon stocks are affected by specific changes in forest

management. For instance, if a new management regime with more residues and/or trees extracted,

or a shorter rotation length, leads to a long term decline in the carbon stock and carbon sink capacity

of the forest estate, this would reduce the climate benefit. On the other hand, an increase in

demand for bioenergy and other forest products could also incentivise changes in forest

management (e.g., improved site preparation, use of nurse trees, advanced genetics, measures to

reduce risks for forest fires or pests/diseases) that enhance forest sink strength and carbon stocks.

4. Forest biomass is a renewable energy source if forest productivity is maintained.

Forest biomass is renewable if it is harvested from forests that are managed such that there is no loss

of productive capacity – i.e., so that growth rate and therefore capacity to sequester carbon are

maintained over successive rotations. Sustainable forest management is key to maintaining healthy

and productive forests. Biomass derived from deforestation should not be recognized as renewable.

5. The climate change effect of using biomass for energy cannot be determined by comparing

GHG emissions at the point of combustion.

It is sometimes stated that CO

stack emissions per MWh inevitably increase when biomass replaces

coal. However, at the point of combustion, wood and coal have similar CO

emission factors, as the

ratio of heating values between the two fuels is similar to the ratio of carbon content. Furthermore,

biomass fuel characteristics (moisture content, grindability, heating value) affect the energy

efficiency of co-firing systems. In large coal power plants, there can be a derating of a few percent, as

there is more flue gas generated per GJ of fuel, which leaves the stack at a temperature above the

ambient temperature resulting in so-called stack losses. However, when the co-firing ratio is low

(<10%) there is usually no significant efficiency penalty. Fuel type (both coal and biomass) also

matters. For low rank coal, biomass co-firing (especially torrefied biomass) can increase the boiler

efficiency and net power plant efficiency. The outcome also depends on modifications made when

power plants are adapted to using biomass (e.g., investments in steam turbine upgrades and internal

waste heat utilization to dry biomass fuel).

More importantly, comparing emissions at the point of combustion does not show the effect on

atmospheric GHG concentrations of switching from fossil fuels to biomass. There is a fundamental

difference between fossil fuels and biomass: burning fossil fuels releases carbon that has been locked

up in the ground for millions of years, while burning biomass emits carbon that is part of the biogenic

carbon cycle. In other words, fossil fuel use increases the total amount of carbon in the biosphere-

atmosphere system, while bioenergy systems operate

within

this system; if the forest carbon stock is

constant there is no net transfer of carbon to the atmosphere.

Instead of comparing GHG emissions at the point of combustion, the biogenic carbon flows and fossil

GHG emissions associated with the complete life cycle of the bioenergy system need to be compared

with the GHG emissions in a realistic reference situation (counterfactual scenario) where energy

sources other than bioenergy are used. Also, indirect impacts (positive or negative) on land use,

wood products and fossil fuel use need to be considered.

KEF, Alm.del - 2020-21 - Bilag 52: Henvendelse af 2/11-20 fra Jan Mayland om brugen af biomasse og den positive indflydelse på CO2-optaget

6. Long-distance transport does not negate the climate benefits of woody biomass as a

renewable energy source.

Fossil energy used in the biomass supply chain is generally small compared to the energy content of

the bioenergy product, even when transported internationally. For example, the fossil fuel use

related to cultivation and processing of wood pellets corresponds to between 2.5 and 15 g CO2/MJ

Transporting pellets between North America and Europe increases supply chain emissions by up to 5

g CO

/MJ

(for

comparison: the life cycle GHG emissions of hard coal (supply & combustion) is around

112 g CO

/MJ).

Thus, long-distance transport does not negate the climate benefits of forest-based

bioenergy; these supply chains still offer substantial climate benefit when sourced from sustainable

biomass.

7. Switching from coal to woody biomass reduces atmospheric CO

over time scales relevant to

climate stabilisation.

Some articles point to the fact that forest-based bioenergy systems can cause a short-term increase

in emissions, although delivering mitigation in the longer term, and claim that bioenergy is not

compatible with climate change goals if it has a payback period of more than a decade, due to the

urgent need to address climate change.

First, there remains disagreement about the appropriate methodological approach for calculating

payback time. Stand-level assessments are in our view not appropriate since they represent the

assessed system as a strict sequence of events (e.g., site preparation, planting or natural

regeneration, thinning and other silvicultural operations, final felling) that in reality occur

simultaneously across the forest landscape (see point 3). The outcome for stand-level assessments

will vary dramatically for the same system, depending on which starting point is chosen (time of

replanting or time of harvest). Moreover, defining a realistic counterfactual for the calculation of

payback times is critical, but challenging, considering the dynamics of forestry systems. Some studies

use unrealistic assumptions for counterfactuals, e.g. assuming that forests planted for commercial

use are left unharvested when there is no demand for bioenergy, and ignoring that most forest

biomass used for bioenergy is a by-product of high value timber.

Second, the relationship between net emissions, global warming and climate stabilisation is complex.

The IPCC 1.5 report

shows many alternative trajectories towards stabilization temperatures of 1.5

and 2 °C. The IPCC emphasizes the need for transformation of all the major sectors of society to

achieve net zero CO

emissions, and finds a requirement for carbon dioxide removal in many

scenarios. The IPCC’s assessment of current scientific understanding does not conclude that

individual measures towards achieving transformation need to meet specific “payback periods”.

or up to 25 g CO2/MJ when fossil fuel is used for drying, which is uncommon in modern pellet plants.

J. Giuntoli, A. Agostini, R. Edwards, L. Marelli, 2015. Solid and gaseous bioenergy pathways: input values and

GHG emissions. JRC Report EUR 27215 EN. ; Jonker, J.G.G., Junginger, M. and Faaij, A., 2014. Carbon payback

period and carbon offset parity point of wood pellet production in the South-eastern United States. Global

Change Biology Bioenergy, 6(4), pp.371-389.

IPCC, 2018: Summary for Policymakers. In:

Global Warming of 1.5°C. An IPCC Special Report on the impacts of

global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in

the context of strengthening the global response to the threat of climate change, sustainable development, and

efforts to eradicate poverty

[Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A.

Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E.

Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)].

World Meteorological Organization, Geneva,

Switzerland, 32 pp.

https://www.ipcc.ch/sr15/chapter/spm/

KEF, Alm.del - 2020-21 - Bilag 52: Henvendelse af 2/11-20 fra Jan Mayland om brugen af biomasse og den positive indflydelse på CO2-optaget

The most important climate change mitigation measure is to transform energy and transport

systems so that we can leave fossil carbon in the ground.

Using bioenergy now, in conjunction with

other renewables, is an important measure to achieve this. Biomass is a storable, dispatchable

energy source that can support the rapid expansion of intermittent renewables, providing grid

stability and balancing. In the longer term, biomass is likely to be primarily used in applications where

the substitution of carbon- based fuels is particularly difficult, such as in aviation and long-distance

marine transportation. Biomass may also be increasingly used in applications that deliver net

negative GHG emissions. For the mid- to longer term, the IPCC 1.5 report found most scenarios that

deliver climate stabilisation at 1.5 or 2 °C require substantial deployment of negative emissions

technologies. Bioenergy linked with carbon capture and storage (BECCS) is one of the major available

options for achieving negative emissions. The further transformation of existing power systems will

depend on how biobased and other technologies develop to meet future demands, including the

development of technologies for providing negative emissions that are not based on biomass.

Concern about near-term emissions is not a strong argument for stopping investments that

contribute to net emissions reduction beyond 2030, be it the scaling-up of battery manufacturing to

support electrification of car fleets, the development of rail infrastructure, or the development of

biomass supply systems and innovation to provide biobased products displacing fossil fuels, cement

and other GHG-intensive products. We assert that it is critical to focus on the global emissions

trajectory required to achieve climate stabilization, acknowledging possible trade-offs between

short- and long-term emissions reduction objectives.

A strong focus on short-term carbon balances

may result in decisions that make long-term climate objectives more difficult to meet.

8. Sustainability governance is required to ensure that woody biomass used for energy makes a

positive contribution to addressing climate change and other societal goals.

Scientific studies have shown that forest-based bioenergy can make a substantial contribution to

climate stabilisation. Sustainability governance is needed to support achievement of this potential,

and minimise the risk of negative outcomes. Many countries have rigorous forest management

regulations requiring implementation of sustainable forest management practices.

Sustainable

forest management, such as defined by FSC- or PEFC-endorsed schemes, is used to manage hundreds

of millions of hectares of forest worldwide, and these practices should be deployed more broadly.

Sustainability requirements have been developed to govern the eligibility of forest biomass for

renewable energy in several countries as well as under the updated European Renewable Energy

Directive. Regulations governing eligibility for bioenergy subsidies in the Netherlands, for example,

stipulate that natural forests cannot be converted, that biodiversity and forest vitality are at least

maintained, that forests must be regrown, and that forest carbon stock must be maintained or

increased in the long term. To secure sustainability compliance and oversight throughout the chain,

all economic operators are supervised by public authorities and the certification schemes involved.

9. Managed forests can provide greater climate benefits than conservation forests.

The cessation of harvesting from forests, to allow them to sequester carbon, has been proposed as a

climate change mitigation option that also can provide other benefits such as biodiversity protection.

There are indeed many good reasons for protecting natural forests. With respect to climate, the IPCC

has pointed out that forests managed for producing sawn timber, bioenergy and other wood

products can make a greater contribution to climate change mitigation than forests managed for

For example, the Montréal Process (https://www.montrealprocess.org/) countries contain 90% of the

world’s temperate and boreal forests and produce 49% of the world’s roundwood.

KEF, Alm.del - 2020-21 - Bilag 52: Henvendelse af 2/11-20 fra Jan Mayland om brugen af biomasse og den positive indflydelse på CO2-optaget

conservation alone. This is for three reasons. First, the sink strength diminishes as conservation

forests approach maturity; production forests maintained in an actively growing state have high sink

strength. Second, wood products displace GHG-intensive materials and fossil fuels. Third, carbon in

forests is vulnerable to loss through natural events such as insect infestations or wildfires, as recently

seen in many parts of the world including Australia and north America. Managing forests can help to

increase the total amount of carbon sequestered in the forest and wood products carbon pools,

reduce the risk of loss of sequestered forest carbon, and reduce fossil fuel use.

10. Managed forests produce wood for multiple products, not just bioenergy.

The picture which is often presented, that whole forest stands are cut for bioenergy alone, is

misleading. Forest biomass for bioenergy is typically obtained from forests managed for multiple

purposes, including production of pulp and saw logs, and provision of other ecosystem services (e.g.,

air quality improvement, water purification, soil stabilization, biodiversity conservation). Bioenergy

systems are components in value chains or processes that aim to produce forest products such as

sawnwood, paper and chemicals. Stems that meet quality requirements are used to produce high

value products such as sawnwood and wood panels, displacing carbon-intensive building materials

such as concrete, steel and aluminium, while residues from forestry operations (tops, branches,

thinnings, wood that is unsuitable for lumber) and wood processing residues are used for bioenergy.

(e.g.

) . When bioenergy from forest biomass displaces fossil fuels, this adds to the climate benefits

of managed forestry.

In summary

Energy from woody biomass can contribute to climate change mitigation, as a renewable fuel. It

should be used efficiently, and when harvested from forests, it must come from sustainably managed

forests, where carbon stocks are maintained or enhanced on a regional or national basis. Forest

bioenergy can support rapid transformation of the energy sector. Furthermore, bioenergy linked with

carbon capture and storage (BECCS) is one of the options that can deliver negative emissions, likely

to be required to meet the temperature targets of the Paris Agreement. Forest management that

maintains or increases carbon stocks, while also producing timber, fibre and energy, contributes to

climate change mitigation by storing carbon on land and replacing carbon-intensive materials and

fossil fuels.

This text has been developed by Göran Berndes, Annette Cowie, Luc Pelkmans and members of IEA

Bioenergy Task 45 (http://task45.ieabioenergy.com/).

Enviva’s website identifies that 17% of feedstock is mill residues, with the remainder being forest biomass.

This forest biomass is not high-value timber, but rather a mix of thinnings, limbs and low-quality stems,

consistent with the biomass sources identified by Matthews et al. (2018) as having low risk, and leading to low

GHG emissions.

KEF, Alm.del - 2020-21 - Bilag 52: Henvendelse af 2/11-20 fra Jan Mayland om brugen af biomasse og den positive indflydelse på CO2-optaget