Tree Frog Editor: This insight paper by political risk analyst Robert McKellar offers a strategic lens on how a second Trump administration is shaping US behaviour as a global actor — an issue with direct implications for trade-exposed sectors. McKellar is a founding partner at Harmattan Risk and the co-author of “Trump’s Second Term: Political Risk and the Forest Products Sector,” an analysis of US trade policy, tariff dynamics, and geopolitical uncertainty. In this paper, he steps back from industry-specific analysis to explore the broader strategic logic — and contradictions — underlying current US global behaviour, providing context for the policy volatility and trade uncertainty facing the sector.

Robert McKellar
The US, a lynchpin global player, has become a change bomb, and having a clear sense of the US as an agent on the world stage is critical to sense-making that can inform appropriate strategic responses. But as it stands, Trump, whose character shapes his administration, is a wildcard. He is seemingly bored to tears by stability in any issue he deals with, and bored by a set menu of priorities. …Do we resign ourselves to perpetually playing catch up with US moves and their reverberations, or is it possible to get ahead of the Trumpian storm with a reasonably accurate sketch of the US as a global actor? If its moves were guided by strategic rationality, we would be able to extrapolate some idea of its future behaviour, and even a sense of how the international system might look in a few years and the critical challenges any given state might present…
Seasoned observers of US politics and international behaviour might have foreseen some of what is happening now, but by and large they did not expect Godzilla. Thus, they have often latched onto their own predispositions to fill in the considerable blanks. This has, for the most part, yielded two poles of interpretation. One is that Trump and his team are acting on a strategic assessment, and that despite apparent mayhem their moves are rational, even coldly calculating. The other is that the US has succumbed to the baser aspects of personal rule. Thus, Trump’s eccentric character and ego are the main source of US global behaviour. …The emerging reality no doubt lies somewhere in between, but to triangulate to an approximation, we need to prod around both poles of interpretation.

VIETNAM — The United States has decided to postpone the tariff increase on certain finished wood products, including upholstered chairs, kitchen cabinets, and bathroom cabinets, from January 1, 2026, to January 1, 2027. The postponement of the tax increase on some finished wood products helps Vietnamese businesses temporarily avoid the policy shock at the beginning of 2026. However, this is not a sign of loosening, but rather a tactical retreat, requiring the wood industry to be more proactive and cautious in policy planning and restructuring the overall development strategy of the entire industry. …Mr. Ngo Sy Hoai, Vice President of the Vietnam Wood and Forest Products Association (VIFOREST), commented that if postponing the tariff increase is considered an “opportunity,” then extreme caution is needed. In reality, tariff pressure has spread throughout the entire supply chain, from domestic manufacturers to importers and retail systems in the US.
OTTAWA — The Canadian minister responsible for Canada-United States trade said Wednesday that Mexico was keen to maintain a trilateral agreement under the free trade pact between the three North American neighbors that is up for review this year. “I am reassured by the Mexican economy secretary … his desire to work with Canada and to ensure that the review of CUSMA results in a strengthened and ongoing trilateral trade arrangement,” Dominic LeBlanc said in a press conference from Mexico. LeBlanc is heading a group of over 370 delegates to Mexico for a six-day trade mission amid fears that U.S. President Donald Trump could ditch the decades-old three-way free trade agreement between the U.S., Mexico, and Canada when it comes up for review later this year. “The Mexicans have very similar interests to Canada,” LeBlanc said. “We both remain absolutely committed to the trilateral free trade agreement and working together as this review process unfolds,” he added.
FINLAND — Metsä Group’s demo plant for a new lignin product has started up in Äänekoski, Finland. The plant uses lignin extracted from the bioproduct mill’s production process as its raw material and it has a nameplate capacity of two tons of a new type of lignin product per day. The plant was built in cooperation with the equipment supplier ANDRITZ. Dow, a leading materials science company, is a key partner. Metsä Group’s new lignin products are called Metsä LigO™. According to Ismo Nousiainen, CEO of Metsä Fibre, part of Metsä Group, the company aims to use the wood raw material, including side streams of pulp production, as efficiently as possible to generate the greatest possible added value. …”The purpose of the new demo plant is to ensure the functionality of the lignin product’s production process, as well as the product’s characteristics and suitability for the market.”
Finland’s forest industry could be forced to reduce capacity again as rising raw material costs and weaker market conditions weigh on profitability. That assessment comes from Juha Varis, senior portfolio manager at S-Bank. …The warning comes amid a more challenging environment for pulp and paper producers. Wood prices remain elevated while demand for several forest industry products has developed more weakly than expected, increasing investor expectations that production cuts may follow. …Björn Wahlroos said that a large and modern pulp mill in Finland could be forced to shut down due to a lack of raw material. His remarks triggered wider discussion within the sector. …Varis said overcapacity in the European forest industry is evident across several segments. He added that investors expect some reduction in capacity but that it remains unclear which companies or plants might be affected.
Australia’s forestry industry says cheap imported timber products are flooding the local market and taking up increased space in local homes and buildings. South Australian Forest Products Association (SAFPA) chief executive Nathan Paine said international trade conditions, fuelled by US tariffs, were responsible for imports reaching Australia at about half the price of local timber. This timber includes laminated veneer lumber (LVL) — a construction product that competes with locally grown radiata pine. …Analysis from Forest and Wood Products Australia showed LVL imports had increased 63% in 2025 compared to a year earlier. …Primary Industries Minister Clare Scriven said the state government could stand behind its past support for the timber industry. Housing Industry Australia chief executive of industry and policy Simon Croft said the pandemic’s trade disruptions had caused a spike in construction costs.
NEW YORK, New York — Mercer International reported fourth quarter 2025 Operating EBITDA of negative $20.1 million compared to positive $99.2 million in the same quarter of 2024 and negative $28.1 million in the third quarter of 2025. In the fourth quarter of 2025, net loss was $308.7 million compared to net income of $16.7 million in the fourth quarter of 2024 and a net loss of $80.8 million in the third quarter of 2025. The net loss in the fourth quarter of 2025 included total non-cash impairments of $238.7 million. This included non-cash impairments of $203.5 million recognized against long-lived assets at our Peace River mill due to the continued down-cycle environment of hardwood pulp markets, $12.2 million against certain obsolete equipment and $23.0 million against pulp inventory due to low prices and high fiber costs. …Mr. Juan Carlos Bueno, CEO: “We continue to prioritize improving liquidity and working capital, committing to rebalancing our asset portfolio and maintaining operating discipline.”
RUSS TAYLOR provided the latest quarterly report from the
Drax Group Plc’s profit declined last year but exceeded analyst estimates, helping lift the shares to their highest level in almost two decades despite significant impairment charges. Adjusted earnings before interest, taxes, depreciation and amortization totaled £947 million ($1.3 billion), beating analyst estimates for £913.7 million. Citigroup Inc. analyst Jenny Ping cited lower pellet costs and record generation at its main biomass plant as supporting the result. The figure was still 11% lower than a year earlier, which Drax attributed to weaker power prices. The company’s share price rose as much as 6.2% to the highest since October 2006 before paring gains. …Drax reaffirmed its target of £600 million to £700 million of annual adjusted EBITDA after 2027 and said it expects 2026 earnings to align with analyst forecasts of about £662 million. The company also expects to return £1 billion to shareholders through dividends and share buybacks from 2025 until 2031, with £2 billion invested in growth areas.
Russia’s lumber industry is entering a period of sustained pressure as production volumes continue to fall and regulatory risks increase. Official data shows that lumber output declined by more than 2.5% last year, reinforcing concerns across the forestry and wood processing sectors. According to Rosstat, Russia’s lumber production dropped from 29.2 million cubic metres in 2024 to 28.48 million cubic metres in 2025. Output remains well below historical highs. Current production is estimated to be 2 to 3 million cubic metres lower than the 2019 peak of roughly 32 million cubic metres. The downturn reflects structural challenges rather than short-term disruption. Domestic demand has weakened. Export markets have narrowed. Access to European machinery and technology has been reduced. These pressures are being felt across both logging and downstream processing operations. China now absorbs more than 70% of Russia’s lumber exports. …Softwood lumber production fell by 3.5% last year. Output declined to 25.7 million cubic metres. 

Tokyo — Housing starts in Japan fell 6.5% from the previous year to 740,667 units in 2025, down for the third straight year and hitting a 62-year low, the land ministry said Friday. The drop reflected deterioration in consumer sentiment amid rising prices, as well as falling demand due to the country’s shrinking population. Of the total, owner-occupied houses dropped 7.7% to 201,285 units, down for the fourth consecutive year. Housing for rent fell 5.0% to 324,991 units, down for the third year in a row. Condominiums and houses for sale decreased 7.6% to 208,169 units, down for the third consecutive year. The results can also be attributed to a law revision in April that led to delays in construction starts for wooden homes with energy-saving features.

Canada Wood’s January market news highlights the continued expansion of Canadian wood products into key international markets, with a strong focus on mass timber, technical innovation, and long-term partnerships. Articles explore new opportunities for Canadian species in China’s growing glulam sector, including efforts to diversify beyond Douglas fir into Hem-Fir, SPF, and yellow cedar. Other features examine rising interest in mass timber construction in South Korea, driven by carbon-reduction goals and modern architectural demand. The January updates also showcase how long-standing Canadian demonstration projects in southern China are building confidence in wood’s durability in challenging climates, helping pave the way for larger, more complex structures. Rounding out the month is news of renewed Canada–China cooperation on wood construction, reinforcing shared commitments to low-carbon building and sustainable urban development. Together, these stories offer a timely snapshot of how Canadian wood expertise is shaping construction practices abroad.
In the construction industry, ideas or materials first seen on the margins of construction processes later become an established part of those processes. …And so it seems to be with Mass Timber Construction (MTC). MTC entered the construction industry as an intriguing approach to reduce embodied carbon. …Today, MTC has become a mainstream building method. Across North America, there are reportedly 2,500 MTC buildings already built or in the planning stages. Similar levels of acceptance are seen in Europe. The world’s leading architects and designers have embraced MTC by incorporating wood components into a wide range of building types and sizes, from commercial offices to housing, campuses, infrastructure and even data centres. Interest and acceptance have moved beyond the pure environmental benefits of using MTC. Economics, simple dollars and cents, are now recognized as a persuasive factor as well. This is because mass timber changes the mechanics of construction..jpg)

BHUBANESWAR: India should explore inclusion of wood-based construction and buildings into the national building code to achieve optimal outcomes for climate change and the economy, opined experts at the 14th National Workshop of Japan International Cooperation Agency Assisted Forestry Projects. The three-day workshop is organised by the Odisha Forestry Sector Development Project focuses on strengthening sustainable wood supply systems, promoting forest certification and expanding agroforestry to meet both domestic and global demands. Odisha Forestry Sector Development Society officials said while the National Building Code of India advocates bamboo for use in construction … international experts at the workshop opined that production and use of wood-based and other natural construction materials can also be explored to reduce dependence on carbon-intensive materials further and encourage sustainable forestry.
There are two types of suncream: chemical and physical. Chemical suncreams absorb the UV rays into heat … physical sunblocks scatter and reflect the UV rays on top of the skin. While they offer a broader spectrum of protection, their photo-catalytic nature and small particle size carry a potential risk. The synthetic compounds have adverse side effects on humans and the environment. …Wood is a material that is very effective at scattering light as a result of its cellular structure, absorbing light through one of its components, lignin. The compound is an organic polymer in the cells of many plants which makes them rigid and woody. It also offers sun protection factors (SPFs) that exceed 180. Lignin has a natural phenolic network that forms a shield against ultraviolet light, offering protection against the sun without the need for petroleum-based filters.The use of lignin as sun protection for skin is promising, particularly as a renewable and waste-free resource. 









TIANJIN, CHINA — The global movement against single-use plastics has triggered a significant transformation in the disposable tableware industry, with wood cutlery emerging as a leading alternative. As regulations tighten and consumer preferences shift toward eco-friendly options, manufacturers of disposable wooden utensils are experiencing unprecedented growth and facing new challenges in scaling production, ensuring sustainability, and meeting diverse international standards. Market analysts observe that regulatory pressure represents the primary driver for this sector’s expansion. The European Union’s Single-Use Plastics Directive, along with similar legislation in Canada, Australia, and numerous U.S. states, has created a substantial and sustained demand for compliant alternatives. Within this regulatory framework, wood, particularly from fast-growing, sustainably managed sources like birch and bamboo, has gained favor for its natural composition, biodegradability, and perceived premium feel compared to other alternatives.





Environmental activists have forced the shutdown of a timber mill in north-west Tasmania. Two women were arrested on trespass charges at the Ta Ann veneer mill in Smithton on Tuesday, as a week-long campaign against native forest logging escalates. …The Bob Brown Foundation said 20 “forest defenders” had occupied the site, with at least one person locking themselves to infrastructure. …The foundation said the protest marked day two of a planned week of action, with participants travelling from across Australia to take part. …In response, Ta Ann Tasmania’s General Manager Robert Yong described the actions as a disruption to a “fully complying lawful business that adds value to sustainable supplies of hardwood logs”. “Their attack on Ta Ann puts the employment and health and safety of employees going about their business at risk,” Yong said.
Forests around the world are quietly transforming, and not for the better. A massive global analysis of more than 31,000 tree species reveals that forests are becoming more uniform, increasingly dominated by fast-growing “sprinter” trees, while slow-growing, long-lived species are disappearing. These slower species act as the backbone of forest ecosystems, storing carbon, stabilizing environments, and supporting rich webs of life—especially in tropical regions where biodiversity is highest. …The research also highlights the growing role of naturalized tree species, meaning trees that originated elsewhere but now grow wild in new regions. Nearly 41 percent of these species share traits like rapid growth and small leaves, which help them survive in disturbed environments. …The study shows that tropical and subtropical regions are likely to experience the most severe impacts from forest homogenization. …According to the researchers, human actions are the main force behind these changes in forest composition. …This makes protecting slow-growing tree species increasingly urgent.
In a controversial study published in April last year, researchers described an astonishing phenomenon: a forest of Norway spruce trees (Picea abies) appeared to ‘sync’ their electrical signaling ahead of a partial solar eclipse. Now there’s a new theory about what was actually going on. Having examined the data, ecologists Ariel Novoplansky and Hezi Yizhaq from Ben-Gurion University of the Negev in Israel propose an explanation that’s not quite as sensational. Novoplansky and Yizhaq suggest that the electrical activity seen in the trees was caused by a temperature drop, a passing thunderstorm, and several local lightning strikes; factors that previous research has shown can trigger similar signaling responses in plants.
Ingka Investments, the investment arm of Ingka Group (IKEA’s largest retailer), has completed the acquisition of forestland from Södra in Latvia and Estonia, following the signing of the agreement announced in October 2025. The transaction is part of Ingka Investments’ strategy to invest in long‑term assets that combine financial resilience with positive impact for the Ingka Group and IKEA business, building a strong foundation for many generations to come. With the acquisition now completed, Ingka Investments will take on the role of long‑term forest owner, with the ambition to manage the forest in a responsible way, while contributing to local economic activity. …Total area included in the acquisition is 135,232 ha in Latvia, and 17,742 ha in Estonia. The purchase price of the asset was EUR 720 million. …With IKEA retail operations in 32 markets, Ingka Group is the largest IKEA retailer and represents 87% of IKEA retail sales.
HCM CITY — Proactive compliance with legal timber sourcing and sustainability standards is essential not only for business survival, but also for repositioning Việt Nam’s wood industry towards greater transparency, responsibility, and higher value creation in global supply chains, speakers said at a seminar in HCM City on January 29. Speaking at the Forest Talk & Link seminar themed “Wood Consumption, Climate Change and Deforestation-Free Requirements”, Võ Quang Hà, Chairman of the HCM City Structure Architecture Wood Association (SAWA), said Việt Nam exported more than US$17 billion worth of wood and wood products in 2025, ranking among the world’s leading furniture exporters. However, an estimated $4–5 billion in export revenue still derives from low-value wood chips and pellets, underscoring the sector’s significant untapped potential for value-added growth. Developing large-timber plantations was identified as a key solution.
Observed annually on February 2, World Wetlands Day marks the adoption of the Ramsar Convention in 1971 and provides an international framework for recognizing the role of wetlands in environmental protection and sustainable development. The 2026 edition is held under the theme “Wetlands and traditional knowledge: Celebrating cultural heritage,” drawing attention to the long-standing relationships between wetland ecosystems and the cultural practices, knowledge systems, and governance structures developed by communities over centuries. The theme highlights how inherited ecological knowledge, often embedded in rituals, seasonal calendars, land-use practices, and spatial organization, has shaped resilient interactions between human settlements and water-based landscapes. …World Wetlands Day 2026 emphasizes the need to reconsider prevailing development models by integrating traditional knowledge with scientific research and planning strategies in efforts toward conservation, restoration, and long-term environmental stewardship.
BOGOTA, Colombia — Chile is reeling from one of its most serious wildfire emergencies in years. Deadly flames sweeping across central and southern parts of the South American country have turned large swaths of forest and towns to ash. Fire scientists say the blazes are being driven not only by extreme heat, drought and wind, but also by how human-shaped landscapes interact with changing climates — a lethal mix that makes fires harder to control. …The fires have razed forests, farmland and hundreds of homes. …What distinguishes Chile’s current fire season isn’t an unusual surge in the number of fires, but the amount of land they are burning. …Miguel Castillo, at the University of Chile… “almost tripling the amount of affected area,” even though the number of fires so far is “within normal margins.” That means fewer ignitions are causing far greater damage — a pattern increasingly seen in extreme wildfire seasons around the world.
Mexico’s National Forestry Commission has issued the 2026 Rules of Operation for its Sustainable Forestry Development for Wellbeing Program, establishing requirements to access federal funding. The rules guidelines governing the allocation of public resources to strengthen sustainable forest development across Mexico. The program is structured around six support components: community forest management and sustainable value chains; commercial and agroforestry plantations; forest restoration; environmental services; forest protection; and capacity building and local development. Through these components, financial support will be provided to ejidos, Indigenous and Afro-Mexican communities, women-led forestry enterprises, and landowners of forested and preferentially forested land. Eligible projects include sustainable forest management, forest and agroforestry plantations, ecosystem restoration, conservation of environmental services, and protection against wildfires, pests, and diseases. Support also covers training and research activities, with a cross-cutting gender approach designed to strengthen women’s participation—particularly Indigenous and Afro-Mexican women—in decision-making and forestry value chains.


Nature markets are systems for measuring an ecological improvement on some land, then creating a representation of that improvement as a credit, which can then be bought and sold. In theory, they allow governments to attract more private investment and diversify funds that help restore nature. The reality is much more complicated. I recently
UK energy company Drax’s ambitions of becoming a significant wood pellet supplier to Asia are in danger of faltering as Japanese policymakers wind back generous subsidies for the biomass sector. Japan is set to soon surpass the UK as the world’s largest wood pellet importer after a post-Fukushima push to diversify power sources that caused hundreds of plants to spring up that burn wood pellets, palm kernel shells — a palm oil byproduct — and other organic materials. But policymakers in Japan are pulling support for the controversial industry after realising the hurdles to bringing down fuel costs. Tokyo has already cut subsidies for new projects of more than 10 megawatts. “The real intention is quite simple: no new government support, phasing out. We don’t see any clear path of bringing down costs in the foreseeable future,” said one government official. “Existing projects might survive but no new projects are coming.”
With European manufacturing output down by up to 40% since 2018, and 200,000 industrial jobs lost last year, the European Confederation of the Paper Industry (Cepi) wants to put biomass, circularity and decarbonization financing back at the heart of the industrial debate. The trade organization relies on a report commissioned from Deloitte. According to this analysis… the use of biomass and efficiency in the circularity of materials are structural advantages for European industry in the face of imported fossil products. The report highlights the fact that the forestry and timber industry, which is already governed by national legislation, has to contend with over a hundred additional European regulations. In Cepi’s view, this overlap is holding back biomass-related industrial development. Moreover, paper collection and recycling remains fragmented across the member states. This heterogeneity complicates the optimization of secondary material flows, despite the fact that paper is one of the most recycled materials in Europe.
When the time is right, a good love song can make all the difference. A study from the University of California, Davis, found that temperature affects the sound and quality of male frogs’ mating calls. In the colder, early weeks of spring, their songs start off sluggishly. In warmer weather, their songs pick up the pace, and female frogs take note. Better songs make the males more attractive mates and suggest to females that conditions are suitable for reproduction. …The results carry implications for conservation amid climate change. …Understanding when frogs breed, how that may shift as the climate warms, and what is driving those shifts is critical to their conservation. …females do not necessarily come to the pond just because the males are calling. The time has to be right for her eggs to survive. That clue lies in the quality of the male’s song, which is more attractive once it’s warmer.
BUENOS AIRES, Argentina — Human-caused climate change had an important impact on the recent ferocious wildfires that engulfed parts of Chile and Argentina’s Patagonia region, making the extremely high-risk conditions that led to widespread burning up to three times more likely than in a world without global warming, a team of researchers warned on Wednesday. The hot, dry and gusty weather that fed last month’s deadly wildfires in central and southern Chile was made around 200% more likely by human-made greenhouse gas emissions while the high-fire-risk conditions that fueled the blazes still racing through southern Argentina were made 150% more likely, according to World Weather Attribution, a scientific initiative that investigates extreme weather events soon after they happen. That probability will only increase, the experts added, as humans continue to blanket the planet with heat-trapping gases.
Scotland would have to plant several hundred thousand hectares of new woodland to achieve net-zero carbon emissions in the livestock sector by 2050 through afforestation alone, a new study has shown. The study by The James Hutton Institute, which was recently published in the journal Science of The Total Environment, investigated how multi-functional afforestation and livestock reduction could contribute to helping Scotland achieve net-zero emissions in the livestock sector by 2050. This goal aligns with the Paris Agreement on climate change. Researchers have simulated a scenario in which approximately 30,000ha per year of new woodland and agroforestry were planted in Scotland between 2020 and 2025. …It is often assumed such planting can only occur at the expense of grazing area, so the researchers coupled this planting effort with a linear decrease in livestock, with an estimated total reduction of approximately 50% of the present herd numbers.
Boreal ecosystems store twice as much carbon as the atmosphere and warm faster than the global average. The current paradigm based on boreal forests and tundra considers that warming will accelerate boreal carbon loss. However, the warming response of Sphagnum peatlands, storing ~40% of boreal carbon stocks, remains under-investigated. …investigations into two long-term warming experiments in Finnish peatlands, we demonstrate that warming enhances soil carbon accumulation in boreal Sphagnum peatlands. This result sharply contrasts with warming-induced carbon loss from boreal forests and tundra, owing to the unique metabolic response of Sphagnum… Our estimates suggest that warming-induced increase of soil carbon in boreal Sphagnum peatlands (assuming no hydrological changes or plant species shifts) may offset nearly half the boreal forest carbon-sink decline or heterotrophic respiration increases in Arctic tundra under warming. These findings highlight the vital but overlooked role of Sphagnum peatlands in counteracting boreal carbon loss under future warming.

A door company in Ireland says it holds the key to turning wood dust into electricity to help power its factory. It’s part of a new multimillion-pound investment by O&S Doors. The company says the onsite renewable heat and energy technology is “a first on the island of Ireland”. Currently the company takes wood dust left over from the manufacturing process and ships it to England where it is used as animal bedding or sent to landfill. But the company – located just outside Benburb in County Tyrone – has revealed new details of its plans to install a biomass-fuelled combined heat and power system. It will turn the dust into millions of units of electricity that can reused to power parts of the factory. …O&S Doors says its biomass-fuelled combined heat and power system will harness MDF dust.
The energy industry initially sold wood pellets as a way to clean up coal. And governments bought into that assumption. But now policymakers are questioning that position and even reversing course. At the center of this debate is a UK-based power company called Drax, which converted Europe’s largest coal plant into a biomass facility—one fueled by wood pellets that it imported from southern states in the United States. The debate raises a multitude of questions, namely those centered on pollution and costs. That is, if the additive creates more pollution than either wind or solar energy, why bother, especially since it comes from a power source that depends on subsidies? Merry Dickinson, campaign director for the Dogwood Alliance, told me that Drax now operates entirely on woody biomass… “The amount of wood required … is beyond what is available as waste wood,” Dickinson says. “…much of the supply consists of whole trees.” [Forbes allows 4 free articles per month]
A new study has shown for the first time that waste cardboard can be used as an effective source of biomass fuel for large-scale power generation, offering a potential new domestic resource to support the UK’s renewable energy sector. Engineers from the University of Nottingham have carried out the first comprehensive characterisation of cardboard as a fuel source and developed a new method to assess its composition. The research … provides a practical tool for evaluating different grades of cardboard for use in energy production. The study found that cardboard displays distinct physical and chemical properties compared with traditional biomass fuels. These include lower carbon content, a reduced heating value and a high level of calcium carbonate fillers, particularly in printed grades. Calcium carbonate is commonly added to cardboard to improve stiffness and optical qualities, but during combustion it forms ash that can reduce boiler performance.