Cutting down trees inevitably leads to more carbon in the environment, but deforestation’s contributions to climate change are vastly overestimated, according to a new study.
Deforestation for timber and farmland is responsible for about 92 billion tons of carbon emissions into the environment since 1900, found a study led by researchers at The Ohio State University and Yale University.
“Our estimate is about a fifth of what was found in previous work showing that deforestation has contributed 484 billion tons of carbon – a third of all manmade emissions – since 1900,” said Brent Sohngen, a professor of environmental and resource economics at Ohio State.He said that widely accepted estimate didn’t take into account the planting of new trees and other forest management techniques that lessen the environmental burden. The model used in this study did take those factors into account, which made a significant difference considering the intensive forest management happening in many parts of the world and the less-intensive, but not inconsequential, management that is happening elsewhere.
The study appears today (Nov. 4, 2019) in the Journal of Forest Economics.
“There was a significant shift toward treating forests as a renewable, rather than nonrenewable, resource in the last century, and we estimate that those reforestation and forest management efforts have led to a far smaller carbon burden on the environment,” Sohngen said, adding that the previous estimate was based on trees’ natural regrowth without any human intervention.
By Alex Devoid, Arizona Daily Star
As the Amazon burns, a bad situation could get worse for forests in Arizona.
“The relationship is very clear,” said Don Falk, a professor at the University of Arizona.
Deforestation in the Amazon accelerates changes in global climate. And these changes eventually affect forests close to home.
They’re driving longer, warmer and more intense wildfire seasons, he said. And they’ve already fueled unprecedented wildfires in Arizona and across the West.
Tropical forests like the Amazon rarely burn when left to nature, but fire has always had a place in the life cycle of forests in Arizona.
Low-intensity fires in Arizona historically cleared the forest floor, limiting the accumulation of wildfire fuel, while leaving mature trees standing.
In the 1880s, people and livestock started interrupting fire’s place in this cycle, Falk said. Then U.S. federal policies suppressed wildfire for decades staring in the 1920s, allowing fuel to accumulate. Changes to global climate dried it out with drought and higher temperatures.
In the worst cases, flames jumped from the ground to the crowns of densely packed trees.
They engulfed old-growth forests, spreading faster and more destructively through more forest than ever before.
In 2002 and 2003, for example, it happened in the peaks above Tucson on Mount Lemmon during the Bullock Fire and then the Aspen Fire. Since then, hundreds of thousands of acres have burnt this way in Arizona.
The Amazon is an important buffer against the warming climate, which has created the conditions for these unprecedented fires. It absorbs around 2 billion of the 40 billion tons of carbon dioxide emitted globally each year.
At least a quarter of the stored carbon on earth is concentrated in tropical forests like the Amazon, which grow on barely 12% of the earth’s land, Falk said.
Forests fires across the globe may contribute to climate change by burning carbon these forests store, according to a 2015 study by researchers from universities across the country.
As the Amazon burns, for example, it absorbs less carbon dioxide.
Meanwhile, more billows from the flames, warming the planet by trapping heat inside the atmosphere.
“It’s a double hit to the global climate system,” Falk said.
By Charolette Duck
Harvesting trees for energy and commercial use goes against most people’s idea of sustainability. Although lumber practices happening across Austria suggest that this isn’t always the case.
WHEN IT COMES to finding new ways to create energy, there’s an assumption that the solution must come from something new. In Austria, however, experts are showing that this is not necessarily the case. Particularly when it comes to something as elementary as burning wood – which is as old as the proverbial hills.
Wood has been used as a heat source for thousands of years, and a power source for more than a century, but the relationship between deforestation and global warming has caused it to be overlooked as a potential alternative source of energy. However, new forestry production and management techniques trialled in Austria suggest that trees might actually have a key role to play in helping to sustainably satisfy our demand for energy – the key is being smart about how we do it.
With forests covering almost half the country – 47 per cent in fact – you don’t have to go far to find a tree in Austria. So, it’s unsurprising that the nation would look to harness this natural resource for its energy needs. But, sustainable forestry is more complicated than just cutting down one tree and replacing it with another. Some clever thinking is required.
“A forest owner has to determine the total volume of growth in their forest per year, every ten years,” says Christian Rakos of the European Pellet Council. “If 1000 cubic metres of wood are added every year by growth of the trees, this is the volume you can cut each year.” Formulas such as this have helped shaped laws that govern the progressive forestry industry in Austria. The math might be a little tricky, but in Austria, any deviation from this formula is taken very seriously indeed– so much so that there are special authorities who ensure that forestry laws are respected. What’s more, these forest police must approve any cutting that’s larger than half a hectare, and check regularly to ensure that harvested areas are replanted immediately, or will naturally regenerate within five years.
Similarly, endangered species are also carefully monitored, and forestry near their habitats severely restricted. If the worst should happen and a forest is wiped out unexpectedly by natural disaster, say from a storm, disease or pests, then the number of harvestable trees the following year will be reduced accordingly.
They might be strict, but these tactics are certainly working. After all, forty percent of Austria’s annual forest growth remains untouched each year, with the net result being that forests are actually increasing in size.
By Emily Jones
If there’s one thing Georgia has a ton of — actually a billion tons — it’s trees. The state leads the country in acres of private timberland and volume of timber harvested. Some in the timber industry think we should turn more of that wood into electricity.
From several stories up at Exelon’s Albany Green Energy plant, you can see a massive pile of chipped up wood, known as biomass. A long conveyor carries it up into the plant, where it’s fed into a boiler.
The biomass burns to make electricity for Georgia Power. Around the corner from the wood pile, a long tube snakes off, carrying leftover steam to power a Proctor and Gamble plant.
From the top of the power plant, you can also see trees: miles and miles of forest in every direction.
But, “we’re not just going out and grabbing a tree, being able to use that tree,” said plant manager James Luckey. “Most of our fuel is coming from treetops, and mill residuals that come from paper mills or something like that.”
They burn the stuff that can’t be made into lumber or paper products. Advocates in the timber industry say there’s plenty of wood waste like that in Georgia that could be made into power.
Johnny Bembry owns a tree farm in Pulaski County. He ends up with waste when he thins his trees to prevent fires and disease.
“That waste from the thinning, it’s going to have to be burned,” Bembry said. “It’s either going to be burned in the woods and wasted, and release carbon in that manner, or it could be burned for energy creation.”
The Georgia Forestry Association, an industry group, is calling for more power plants around the state that burn biomass. They say it’s a good use for leftover wood, cleaner than coal, and renewable because you can keep growing trees.
“They’re talking about sustainability in terms of, ‘well, we replant,’” said Vicki Weeks of the Dogwood Alliance, which opposes biomass power. “We’re talking about, we can’t afford to lose 40 to 50 years in terms of CO2 uptake.”
A documentary about the burning of wood at an industrial scale for energy, “BURNED: Are Trees the New Coal?” tells the little-known story of the accelerating destruction of our forests for fuel, and probes the policy loopholes, huge subsidies, and blatant greenwashing of the burgeoning biomass power industry.
By independent filmmakers Marlboro Films, LLC: Alan Dater, Lisa Merton, and Chris Hardee.
Is wood pellet-based electricity less carbon-intensive than coal-based electricity? It depends on perspectives, baselines, feedstocks, and forest management practices
P Dwivedi, M Khanna, and Madisen Fuller
Some studies suggest that the carbon intensity of electricity generated in the United Kingdom by using imported wood pellets from the southern United States is higher than that of coal-based electricity, whereas other studies suggest that the use of wood pellet-based electricity reduces carbon emissions significantly, relative to coal-based electricity. We developed the Forest Bioenergy Carbon Accounting Model (ForBioCAM 1.0) to analyze factors that influence the carbon intensity of wood pellet-based electricity, using a common set of assumptions and the same system boundary. We show that widely differing assessments of the carbon intensity of wood pellet-based electricity depend on the choice of forest management perspectives (landscape or stand), baselines (no harvest, or harvesting for the manufacture of traditional finished wood products), feedstocks (whole trees, pulpwood, or logging residues), forest management practices (change in rotation age), and the duration of the analysis itself. Unlike with a stand perspective, we demonstrate conditions under which a landscape perspective results in carbon savings net of avoided emissions from coal-based electricity. Our results also suggest that the two perspectives of forest management converge in their assessment of the positive carbon effects of various feedstock types used to manufacture wood pellets relative to a no-harvest baseline, and that the use of whole trees for wood pellets results in net carbon savings after a break-even period of about three years relative to a no-harvest scenario. The results of this study can guide future policy deliberations on the use of wood pellets as a renewable energy source worldwide.
By Mike Gaworecki
New research provides yet more evidence that granting indigenous and other local communities formal title to their traditional lands can be a boon to efforts to conserve forests.
Deforestation is responsible for as much as 10 percent of total global carbon emissions, which means that finding effective means of keeping forests standing is crucial to global efforts to halt climate change.
Previous studies have found that securing indigenous land rights is a successful path to keeping forests and the carbon sinks they represent intact. A 2016 analysis by the World Resources Institute (WRI) focused on Bolivia, Brazil, and Colombia, for instance, determined that tenure-secure indigenous forestlands could help avoid the release of carbon emissions equivalent to taking nine to 12 million passenger vehicles off the road over the next 20 years.
According to another report released last year as part of a collaborative research project by the Woods Hole Research Center, the Rights and Resources Initiative, and WRI, there is a lot of carbon stored on indigenous lands, making increased land titling a significant opportunity for climate mitigation. But the research found that, while indigenous peoples and other local forest communities manage at least 24 percent of the carbon stored above-ground in Earth’s tropical forests, or some 54,546 million metric tons of carbon (MtC), more than 22,000 MtC of that is at risk of deforestation or degradation because it is found in regions where the local communities do not enjoy formal recognition of their claim to the land.
A more recent study not only found that well-trained indigenous technicians are every bit as capable of collecting the necessary data to monitor forest carbon stocks as professionals, but that in some cases, at least, they can do it quicker and cheaper than the professionals.
The efficacy of land titling as a forest protection measure are less clear, however. But now the authors of a study published in the Proceedings of the National Academy of Sciences (PNAS) last week say they found that forest clearance is actually reduced by more than three-quarters and forest disturbance by roughly two-thirds over the two-year time span immediately following the granting of land title to an indigenous community.
VTT Technical Research Centre of Finland Ltd, the leading research and technology company in the Nordic countries, is seeking a carbon capture technology for Finnish power and heat production plants. The first pilots were implemented, using wood pellets, at VTT’s Bioruukki and the results are promising.
Finland is well on its way to achieving the 2020 climate goals, but it is already clear that the goals for 2050 are impossible to attain without major changes in energy production and other industries.
VTT has calculated that Carbon Capture and Storage (CCS) could cost-effectively cover one third of Finland’s share of reductions in greenhouse gas emissions by 2050. More than 80 per cent of carbon capture measures would concern the burning or refining biomass, and the rest would concern the coal-intensive industry. Biomass is a renewable natural fuel that binds carbon dioxide from the atmosphere as it grows. If the carbon dioxide generated by burning of biomass is captured and permanently stored deep in bedrock, carbon dioxide can be removed from the atmosphere.
Chemical Looping Combustion (CLC) is a promising carbon capture technology suitable for new plants. This technology produces flue gas that consists of carbon dioxide and water vapour as a by-product. Since the gas contains no nitrogen, carbon dioxide is easy to separate and capture – unlike in alternative technologies. Biomass burning with the help of the CLC technology (Bio-CLC) is a new research area, and VTT’s experiments in the sector are pioneering on a global scale.
The California legislature has passed legislation that aims, in part, to support existing biomass plants within the state. The bill, SB 859, features an expenditure plan for unallocated cap-and-trade proceeds.