forests

Danger For North American Biomes | Earth Wise

October 8, 2020 By EarthWise Leave a Comment

Biomes are large, naturally occurring communities of flora and fauna that occupy a major habitat. Examples include several different kinds of forests, grasslands, deserts, and tundra. According to a new study published in the journal Global Change Biology, the resilience of North America’s plant biomes is declining, which means that they are in danger of succumbing to a major extinction event.

The research analyzed over 14,000 fossil pollen samples from 358 sites across North America for the purpose of reconstructing their “landscape resilience”, meaning the ability of the habitats to persist or quickly rebound in response to disturbances.

Some 13,000 years ago, North American ecosystems were destabilized by the one-two punch of the retreat of glaciers at the end of the last ice age along with the arrival of humans. That combination resulted in the extinction of large terrestrial mammals on the continent.

Today, there is a comparable one-two punch created by the rapidly changing climate combined with the dramatic expansion of the footprint of human civilization. The result could again be the demise of some of North America’s biomes. In past eras, forests persisted longer than grasslands, but also took longer to reestablish after disruptions. Overall, only 64% of historic biomes regained their original ecosystem type.

The scientists said that strategic conservation effects could help counteract or slow down the impacts of climate change in the coming decades. In particular, efforts focusing on improving landscape and ecosystem resilience by increasing local connectivity and concentrating on regions with high richness and diversity could have the greatest positive effect.

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North American Biomes Are Losing Their Resilience, With Risks for Mass Extinctions

Photo, posted January 9, 2020, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Dangers Of Negative Emissions Technologies | Earth Wise

September 28, 2020 By EarthWise Leave a Comment

Reducing carbon emissions is not easy and there are plenty of people who don’t even want to try for various reasons, generally related to their perceived economic interests and convenience. As a result, there is a great deal of interest in so-called negative emissions technologies or NETs. These are methods for removing carbon dioxide from the atmosphere. Even the UN Intergovernmental Panel on Climate Change assumes that NETs will play a role in mitigating the effects of climate change and meeting international goals.

The most widely studied approaches to negative emissions technology are bioenergy with carbon capture and storage – which entails growing crops for fuel, and then capturing and burying the CO2 produced from burning the fuel; planting more forests; and direct air capture, which involves actually pulling CO2 out of the air and storing it – probably underground.

A new study published in Nature Climate Change points out that none of these technologies has even been tried at the demonstration scale, much less at the massive levels required to make a dent in current CO2 emissions.

Their analysis of the biofuel and reforestation strategies show that each would take up vast land and water resources already needed for agriculture and nature. Air capture uses less water than the other two approaches, but still uses quite a bit and even more energy, which if supplied by fossil fuels, would offset the benefits of carbon capture.

Negative emissions technologies may well play an important role in combating climate change, but it is essential that we understand what the consequences will be from implementing them. We need to know the pitfalls that could arise. It would be a major mistake to simply count on NETs to be some kind of silver bullet.

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Remove CO2 from the air? Don’t bet on it before examining costs, researchers say

Photo, posted January 11, 2008, courtesy of Al Pavangkanan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Restoring Tropical Forests | Earth Wise

September 10, 2020 By EarthWise Leave a Comment

Tropical forests store more than half of the world’s above-ground carbon. For this reason, deforestation is one of the greatest threats to global climate regulation. Once forests are degraded through partial clearing and agricultural conversion, they are often perceived as no longer having much ecological value even though degraded forests still provide important ecosystem services despite no longer storing as much carbon.

As a result, once forests have been degraded, they tend to be seen as prime candidates for full conversion to agricultural plantations. But this is not actually the case.

An international team of scientists, including researchers from Arizona State University’s Center for Global Discovery and Conservation Science, has provided the first long-term comparison of above-ground carbon recovery rates between naturally regenerating and actively restored forests in Southeast Asia.

First of all, the research shows that allowing forests to regenerate naturally results in significant amounts of restored above-ground carbon storage. It is definitely worthwhile to allow forests to recover rather than giving up on them and putting the land to other uses.

But more importantly, the researchers found that forest areas that undergo active restoration recover their carbon-storing ability 50% faster than naturally recovering forests.

Restoration methods include planting native tree species and thinning vegetation around saplings to improve their chances of survival.

These findings suggest that restoring tropical forests is a viable and highly scalable solution to regaining lost carbon stocks on land. What is needed is sufficient incentive to engage in active forest restoration. The current price of carbon is not sufficient to pay for restoration, but as the climate crisis intensifies, this is likely to change.

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Tempe to Hawaii: ASU professors teach Hawaiian youth about coral reef conservation

Photo, posted May 22, 2008, courtesy of Eric Chan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tree-Planting Is Not Necessarily A Good Thing | Earth Wise

July 31, 2020 By EarthWise Leave a Comment

There is no question that forests have a major role in efforts to combat climate change as well as to slow biodiversity loss. As a result, tree-planting on a massive scale has gained traction as a strategy and there have been major commitments made to plant billions of trees around the world.

A new study at Stanford University has rigorously analyzed the potential effects of these efforts and has found some significant problems. For example, the Bonn Challenge, which seeks to restore an area of forest more than eight times the size of California over the next 10 years, has 80% of its commitments in the form of planting monoculture tree plantations or a limited mix of trees that produce fruit and rubber, rather than restoring natural forests. The problem is that plantations have significantly less potential for carbon sequestration, habitat creation, and erosion control than natural forests. The potential benefits of the planting dwindle further if planted trees replace natural flora – forests, grasslands, or savannahs – which are ecosystems that have evolved to support local biodiversity.

The study looked at previous policies that created subsidies for planting trees. Chile’s Decree Law, in effect from 1974 to 2012, has served as a model for similar policies in a number of countries. Those subsidies further reduced native forest cover by encouraging the establishment of plantations in places where forests might have naturally regenerated. The subsidies expanded the area covered by trees, but decreased the area of native forests.

The study recommends that nations should design and enforce their forest subsidy policies to avoid undesirable ecological impacts and actually promote the recovery of carbon- and biodiversity-rich ecosystems.

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Poorly designed tree-planting campaigns could do more harm than good, according to Stanford researcher and others

Photo, posted April 28, 2016, courtesy of the U.S. Department of State via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A High-Tech Fire Alarm | Earth Wise

July 23, 2020 By EarthWise Leave a Comment

In recent years, wildfires have been a global problem, notably in California, Brazil, and Australia. It has become increasingly important to be able to respond to new fires as soon and as quickly as possible. Such response can make the task of extinguishing them easier, thereby reducing the amount of damage and the loss of property and life.

Traditional methods for detecting forest fires include satellite monitoring, ground patrols, and watch towers, all of which have high labor and financial costs but suffer from low efficiency. Remote sensing technologies are becoming increasingly common but rely on batteries for power, requiring servicing in remote locations to replace depleted batteries. Solar cells represent an alternative to batteries, but it is challenging to use them in forests because of shading and foliage coverage.

A team of researchers at Michigan State University has developed a remote forest fire detection and alarm system powered by nothing more than the movement of tree limbs in the wind. The device is known as an MC-TENG, which is an acronym for multilayered cylindrical triboelectric nanogenerator. The triboelectric effect is a phenomenon where certain materials become electrically charged when they separate from a second material with which they were previously in contact. In the new device, two cylindrical sleeves fit within one another – one anchored and the other free to slide. The device is tied to a tree branch and when the branch sporadically moves in the wind, electricity is generated and stored in a carbon-nanotube-based micro supercapacitor. This powers a sensing system that can continuously monitor environmental conditions without requiring any maintenance.

A combination of carbon monoxide and temperature sensors provides a high-tech fire alarm that can operate continuously in the most remote forest.

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Self-Powered Alarm Fights Forest Fires, Monitors Environment

Photo, posted August 3, 2012, courtesy of Lukas Schlagenhauf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Planting Trees and Climate Change | Earth Wise

June 1, 2020 By EarthWise Leave a Comment

Forests are among the most important natural carbon sinks. Trees remove carbon from the air and store it in their trunks, branches, and leaves, and transfer part of it into the soil. But in some regions, these natural carbon sinks are starting to weaken due to deforestation, forest degradation, and the impacts of climate change. This problem has led some climate mitigation projects to focus on increasing the overall number of trees on the planet.

But, according to a paper recently published in the journal Science, “we can’t plant our way out of climate change.” That’s the simple message from Restoration Ecologist Karen Holl and University of São Paulo Professor Pedro Brancalion to anyone who thinks planting one trillion trees will reverse the effects of climate change. They say planting more trees is only one piece of the puzzle. Any initiatives like 1t.org or the Trillion Tree Campaign must be done carefully and be accompanied by commitments to long-term management.

Tree plantings can provide many environmental benefits, including improving water quality, biodiversity, and increasing shade. But trees can sometimes have undesirable impacts, such as harming native species and ecosystems or reducing water availability, depending on where and how the trees are planted.

The authors suggest four principles that should guide forest enhancement initiatives: reduce forest clearing and degradation, balance ecological and social goals, view tree plantings as one part of a multifaceted solution, and plan, coordinate and monitor the work.

While tree plantings can clearly be part of the solution, slowing the pace of climate change requires a comprehensive approach that must start with burning less fossil fuels.

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Challenges in tree-planting programs

Planting trees is no panacea for climate change

Photo, posted December 1, 2019, courtesy of Akuppa John Wigham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Natural Habitats And Strawberry Farms | Earth Wise

April 22, 2020 By EarthWise Leave a Comment

According to a new study led by researchers from the University of California – Davis, conserving natural habitat around strawberry fields can protect farmers’ yields, their bottom line, and the environment. The study also suggests that conserving natural habitat in this way has no detectable threat to food safety.

In this study, which was recently published in the journal Ecological Applications, the research team conducted surveys and experiments at 20 strawberry farms along California’s Central Coast. This region is responsible for 43% of the nation’s strawberry production.

The researchers found that strawberry farmers were better off with natural habitat, like forests, grasslands, wetlands, and shrubs, around their farms than without it. According to the study’s models, adding natural habitat can reduce crop damage costs by 23%. Removing natural habitat can increase costs by as much as 76%.

Importantly, the strawberry farms with natural habitat surrounding them showed no signs of increased fecal contamination. While bird feces were regularly encountered on the ground, only 2 of 10,000 strawberries examined show signs of direct fecal contamination. Those contaminated berries would be discarded during the hand-harvesting process.

These findings run contradictory to current best practice recommendations that support natural habitat removal around strawberry farms in order to decrease bird fecal contamination and crop damage. These food safety requirements were a consequence of the deadly outbreak of E. coli in 2006, which was traced back to spinach grown in this region.

It seems like our agricultural landscapes can both support and benefit from biodiversity.

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Natural habitat around farms a win for strawberry growers, birds and consumers

Photo, posted June 16, 2011, courtesy of the USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Rising Threat Of Rising Seas | Earth Wise

February 3, 2020 By EarthWise Leave a Comment

Global sea level rose by about 6 inches during the 20th century. It is currently rising more than twice as fast and accelerating. The rate of rise was 2.5 times faster from 2006 to 2016 than it was for nearly all of the 20th century.

Sea level rise occurs when glaciers and ice sheets lose mass. Much of that meltwater comes from Greenland and Antarctica. But levels also rise because, as water warms, it expands. Added to that are the effects of human activities such as groundwater depletion and a geological phenomenon called isostatic adjustment that is going on in parts of the East Coast where the land is actually sinking.

In Atlantic Canada, sea level rise is outpacing the global average and has already led to boardwalks swamped by swelling tides, drowned forests, submerged wharfs, and threatened historic shoreline buildings.

Recent research suggests that globally, land now occupied by 300 million people could be affected by floods at least once a year by 2050 unless carbon emissions are significantly reduced, and coastal defenses strengthened. (This new figure is more than three times higher than earlier estimates).

Researchers at Dalhousie University in Nova Scotia are studying nature-based strategies for mitigating the effects of the rising seas. These include conserving or restoring coastal ecosystems like dunes, wetlands, and reefs which could provide protection at a lower cost than building seawalls and other man-made obstacles. Wetlands, for example, can reduce the force of waves and act as obstacles to storm surges, while also trapping sediment and stemming erosion. Wetlands also serve as important carbon stores, but it is estimated that roughly half of the world’s coastal wetlands have been lost over the past 100 years to human activity and extreme weather events.

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The Looming Threat of Rising Sea Levels – And What We Can Do About it

Photo, posted February 14, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bioacoustics

December 5, 2019 By EarthWise Leave a Comment

Researchers are increasingly placing microphones in forests and other ecosystems to monitor birds, insects, frogs, and other animals. Advances in technology are enabling the wide-spread use of bioacoustics as an important research tool.

Studying animals in their natural habitat Is often a difficult task. For one thing, many animals are difficult to find, and the presence of humans disrupts their behavior or even drives them off. Remote cameras are useful, but cameras can only see what is in front of them and aren’t much use for detecting small animals, hidden animals, or ones high up in trees.

Biologists have long recognized the value of recording sound to identify animals and learn about their havior. Animal sounds can be as definitive a means of identification as visual images and microphones can pick up the sounds from animals located anywhere within their detection range.

The two advances in technology that are turning bioacoustics into a widely used tool are a steep drop in the price of recording equipment and the rapidly expanding capabilities of user-friendly artificial intelligence algorithms.

Autonomous environmental audio recorders tended to cost between $500 and $1000 until quite recently. Now, such equipment can be had for as little as $70.

The other big challenge is analyzing audio data. Finding specific animal sounds among hundreds of hours of recordings is an untenably tedious task. Identifying the characteristic sounds of specific species in crowded environments is a tricky business. But neural network-based artificial intelligence technology is making such big data analysis quite practical and, remarkably, it is becoming quite user-friendly.

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Listening to Nature: The Emerging Field of Bioacoustics

Photo, posted January 28, 2013, courtesy of Felix Uribe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Out-Migration And Reforestation

November 4, 2019 By EarthWise Leave a Comment

A challenging global trend is that of deforestation in developing countries. But there are places where the opposite trend is happening. Nepal is one such place.

According to satellite imaging, in 1992 forest covered 26% of Nepal. As of 2016, that number was 45%.

To some extent, the forest regrowth was a result of policy changes from about three decades ago, when the government began removing management authority from bureaucrats and shifting it to local communities across the country. This local management helped to reduce illegal logging and many local villages undertook tree-planting campaigns.

But perhaps a bigger factor at play is human migration. In recent decades, millions of Nepalis have left the country to work in the Persian Gulf, Southeast Asia, and elsewhere. The out-migrants wire money home and meanwhile, families left behind rely less on forest products or abandon farmland, aiding reforestation. A 2018 study showed that the areas with the highest out-migration experience, on average, had the most forest recovery.

Globally, migration has important impacts on forests, but not always positive ones. In many countries, forests seem to recover as people leave rural areas to work elsewhere. El Salvador, for example, has seen a rebound of its forests as many of its rural residents move to cities or even to the United States. But in Guatemala and Nicaragua, the return of migrants bringing money they have earned overseas has led to an expansion of cattle ranching that has harmed forests.

The global relationship between migration and forests is a complicated one that depends on whether the migration is one-way or “circular” (meaning that the migrants eventually return) and how returning migrants make use of their earnings from abroad.

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In Nepal, Out-Migration Is Helping Fuel a Forest Resurgence

Photo, posted September 30, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfires And Carbon

September 17, 2019 By EarthWise Leave a Comment

This summer has been an unprecedented year for fires in the Arctic. Major fires have burned throughout the Arctic in Russia, Canada, and Greenland. In total these fires released 50 million tons of carbon dioxide in June alone, which is as much as Sweden emits in an entire year.

In an average year, wildfires around the world burn an area equivalent to the size of India and emit more carbon dioxide to the atmosphere than global road, rail, shipping and air transport combined.

Ordinarily, this is part of a natural cycle. As vegetation in burned areas regrows, it draws CO2 back out of the atmosphere through photosynthesis. This is part of the fire-recovery cycle, which can take less than a year in grasslands, but decades in forests. But in Arctic or tropical peatlands, full recovery may not occur for centuries.

A recent study looked at and quantified the important role that charcoal plays in helping to compensate for carbon emissions from fires. In wildfires, some of the vegetation is not consumed by burning, but instead is transformed to charcoal – referred to as pyrogenic carbon. This carbon-rich material can be stored in soils and oceans over very long time periods.

Researchers have combined field studies, satellite data, and modelling to quantify the amount of carbon that is placed in storage in the form of charcoal. Their results are that the production of pyrogenic carbon amounts to about 12% of the CO2 emissions from fires and can be considered a significant buffer for landscape fire emissions.

Charcoal does not represent a solution to the problem of increasingly intense wildfires, but it is important to take it into account in understanding what is happening.

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How wildfires trap carbon for centuries to millennia

Photo, posted August 17, 2018, courtesy of the Bureau of Land Management Oregon and Washington via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fighting Climate Change With Trees

August 20, 2019 By EarthWise Leave a Comment

We cut down forests all around the world for a myriad of reasons, including livestock grazing, agricultural production, timber, and urban development. But what if we stopped cutting down forests for these things and additionally grew new forests on vacant lots and any other available parcels of land on earth? What impact could this have on our survival?

For the first time, scientists have quantified what impact this plan could have. According to a new study by researchers at ETH Zurich – a university that specializes in science, technology, and engineering – the planet could support nearly 2.5 billion additional acres of forest without shrinking current cities and farms. When all those acres of forest mature, the trees could store an extra 200 gigatons of carbon. This reforestation could stave off the most devastating impacts of global climate change.

Russia could restore the most acres of forest – 373 million acres to be precise – followed by the United States with 255 million acres and Canada with 193 million acres. Australia, Brazil, and China also have large areas well-suited for forest restoration.

The average global temperature has risen by 1.8 degrees Fahrenheit since the start of the industrial age with its surge in greenhouse gas emissions. Temperatures are projected to rise even more in the coming years as the planet continues to warm.

Trees absorb CO2 from the atmosphere and store it in their roots and branches. The absorbed carbon becomes part of the soil when trees die and decompose, and it can linger there for millennia depending on things like temperature and soil management. Trees are critical in the fight against climate change.

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How trees could save the climate

Photo, posted June 18, 2011, courtesy of K.W. Barrett via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Price of Chocolate

April 18, 2019 By EarthWise Leave a Comment

The Ivory Coast has lost more than 80% of its forests in the last 50 years, mainly as a result of cocoa production.

The Ivory Coast is a West African country the size of New Mexico and it produces more than a third of the world’s cocoa. But around 40% of the country’s cocoa crop – supplying more than a tenth of the world’s chocolate bars – is grown illegally in the country’s national parks and 230 supposedly protected government-owned forests.

Over the decades, as many as one million landless people from drought-stricken places like Mali and Burkina Faso moved into national parks and protected forests and started farming cocoa. The Marahoue National Park alone has 30,000 illegal inhabitants.

Most cocoa is grown in monocultures of what is known as the full-sun system, which requires the removal of all surrounding trees. As a result, many allegedly protected areas have been completely converted into farms. Most of the cocoa in the Ivory Coast is grown on small farms, typically plots of 7 to 10 acres. The farmers are caught in an exploitative and corrupt system of cocoa trading and land appropriation, and most earn less than a dollar a day. Meanwhile, government agencies charged with protecting the forests are more interested in collecting bribes than safeguarding woodlands.

The Ivory Coast government is unveiling a plan to actually remove protection from most of its remaining forests and hand them over to the world’s chocolate traders. The claim is that this will protect other forests by improving cocoa productivity in already deforested areas. Needless to say, conservation groups are dubious that the new plan will positively impact an already terrible situation.

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The Real Price of a Chocolate Bar: West Africa’s Rainforests

Photo, posted April 17, 2015, courtesy of Tom Coady via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Natural Climate Solutions Are Not Enough

April 1, 2019 By EarthWise Leave a Comment

A new policy perspective published in Science by researchers at seven prestigious institutions looked at the role of natural science solutions in stabilizing the Earth’s climate for people and ecosystems. While they asserted that it is imperative to ramp up natural climate solutions, they also concluded that natural solutions alone will not be sufficient.

Natural science solutions include such things as enhancing carbon sinks from forests, agriculture and other lands. Doing these things are very beneficial in their own right as they lead to improved forests, croplands, grazing lands, and wetlands.

However, these things will not be enough to meet the goals of the Paris Climate Agreement and must be combined with rapid efforts to decrease emissions from the energy and industrial sectors. Among their various findings, the researchers warn that a ten-year delay in emissions reductions from these sectors could completely negate any potential benefits of natural climate solutions.

As has become increasingly clear, there is not an either-or situation with regard to the actions that need to be taken with respect to climate change.

Maximizing natural climate solutions and reducing emissions from the energy and industrial sectors will provide broad benefits beyond climate change mitigation. Doing these things will improve forests and habitats, reduce the risk of wildfires, and decrease air and water pollution thereby improving human health and well-being.

Of course, to reduce cumulative emissions and put a cap on the warming of the planet, there will need to be policy mechanisms and incentives in place that support both natural climate solutions and increasing mitigation efforts across the energy and industrial sectors.

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Natural Climate Solutions Are Not Enough

Photo, posted February 11, 2012, courtesy of Joao Andre O. Dias via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfire Pollution

January 24, 2019 By EarthWise Leave a Comment

California’s record-breaking wildfires this past season have been an unmitigated disaster with respect to loss of life, property, impact on human health, and in multiple other ways. And as if all of that was not bad enough, the impact on carbon emissions into the atmosphere was equally catastrophic. The wildfires were deadly and cost billions of dollars but were also terrible for the environment and for the public’s health.

According to estimates from the U.S. Department of the Interior, the California wildfires released emissions equivalent to about 68 million tons of carbon dioxide into the atmosphere. That is equal to the emissions from generating one year’s worth of electricity in the state, or about 15% of the total annual emissions in the state of California.

It is a vicious circle in which the changes to the climate that have lengthened the fire season and shortened the precipitation season are creating additional contributions to the warming of the climate.

Over the past century, California has warmed by about 3 degrees Fahrenheit. That extra-warmed air sucks water out of plants and soils, resulting in trees, shrubs, and rolling grasslands that are dry and primed to burn. That vegetation-drying effect compounds with every additional degree of warming. Plants lose their water more efficiently as temperatures get higher.

The result is that wildfires are increasing in size both in California and across the western United States. Fire experts at Columbia University estimate that since the 1980s, the warming climate has contributed to an extra 10 million acres of burning in western forests – an area about the size of Massachusetts and Connecticut combined.

It’s a bad situation that is getting worse.

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