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Planting Rocks To Capture Carbon | Earth Wise

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Getting humanity to stop dumping carbon dioxide into the atmosphere continues to be very challenging regardless of how increasingly apparent the need to do so becomes.  For this reason, climate change mitigation strategies increasingly include interventions in the form of removing carbon dioxide that is already there.  There are a variety of ways to draw carbon dioxide out of the atmosphere, but they face a host of technological, economic, and even environmental difficulties.

A new study at Yale University evaluated a type of climate intervention called enhanced rock weathering.  Rock weathering is a natural chemical process by which certain minerals absorb carbon dioxide over time.  Enhanced rock weathering is simply speeding up weathering such so it can have beneficial results soon enough to make a difference.

The study explored the potential of applying crushed basalt, which is a fast-weathering rock that forms when lava cools, to agricultural fields around the world.  Basically, the idea is for farmers to mix the crushed rocks into their fields. There is no real downside to doing this.  In fact, adding crushed basalt to fields rejuvenates depleted soils and helps counter ocean acidification.

The study simulated the results of enhanced rock weathering on 1,000 agricultural sites around the world.  Over a 75-year period, these sites would remove 64 billion tons of carbon dioxide from the atmosphere.  This is roughly the amount climate scientists believe is needed to take out of the atmosphere. 

Enhanced rock weathering has been used on a small scale on farms around the world.  Perhaps it is time to ramp up its use.

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‘Planting’ rocks in farms, along with emissions reductions, could help meet key IPCC carbon removal goal

Photo, posted January 14, 2023, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Removing Carbon Dioxide Won’t Get the Job Done | Earth Wise

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Limiting global warming to no more than 1.5-2 degrees Celsius above pre-industrial levels is a crucial goal for humankind.  Countries, companies, and other organizations around the world have committed to achieving ‘net zero’ emissions.  This is distinct from zero emissions in that it includes removing carbon dioxide from the atmosphere to offset the amounts we are putting into it.  Carbon dioxide removal is increasingly touted as the way to achieve emission goals.  But it is a realistic strategy?  According to a recent paper by a leading climate scientist in the journal Nature, the answer in the short term is decidedly no.

In 2022, the world emitted 45 billion tons of carbon dioxide into the atmosphere.  Last year’s bipartisan Infrastructure Law earmarked $3.5 billion for developing four direct air capture hubs in the US.  Each of these is expected to eventually be able to extract a little over a million tons of CO2 from the air each year. These hubs combined would therefore remove about 52 minutes’ worth of the year’s emissions over the course of the year. 

The bottom line is that unless we drastically reduce emissions, all the carbon dioxide removal strategies combined will scarcely make a dent in the problem.

We will never be able to eliminate all sources of emissions, particularly from certain industries, and carbon dioxide removal will be a very important technology to address those emissions, but in the big picture, it is essential that the world decarbonizes as much as possible and as soon as possible.

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Carbon dioxide removal is not a current climate solution — we need to change the narrative

Photo, posted January 19, 2009, courtesy of Wladimir Labeikovsky via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Ocean-based Climate Intervention And Deep-sea Ecosystems | Earth Wise

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Deep-sea ecosystems cover more than 40% of the Earth.  These regions are some of the least well-known and understood areas of our planet but are home to numerous ecosystems.  The deep seas are already directly exposed to the effects of human-induced climate change but could potentially be greatly threatened by efforts to artificially counteract climate change.

A class of geoengineering solutions called ocean-based climate interventions are increasingly being claimed as promising ways to mitigate climate change.  Such interventions would remove carbon dioxide from the atmosphere and sequester it in the deep sea.  There is very little known about the impact of such efforts on ocean biogeochemistry and the biodiversity of ocean ecosystems.

One approach is direct CO2 injection into the deep ocean, which would sequester large amounts of it and reduce the concentration in the atmosphere.  However, too much carbon dioxide in the water is called hypercapnia, which can have serious consequences on marine life.

Other approaches include ocean fertilization – which is enhancing phytoplankton production at the surface, leading to their eventual deposition on the deep-sea floor – and crop waste deposition – which is deep-sea disposal of terrestrial crop waste. 

A multinational study led by the Scripps Institution of Oceanography warns that there needs to be much more research and governance before any such interventions ever take place.  The deep sea faces unprecedented threats from industrial fisheries, pollution, warming, deoxygenation, acidification, and other climate-related problems.  Ocean-based climate intervention represents yet another serious threat to the functioning of these essential ecosystems.

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HKU Marine Scientist contributes to research assessing the potential risks of ocean-based climate intervention technologies on deep-sea ecosystems

Photo, posted January 6, 2010, courtesy of Emrys Roberts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pulling Carbon Dioxide Out Of Seawater | Earth Wise

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The world’s largest sink for carbon dioxide from the atmosphere is the ocean.  The world’s oceans soak up 30-40% of all the gas produced by human activities.  Dissolving carbon dioxide in water produces carbonic acid.   This is the reason that oceans are becoming increasingly acidic, which is causing serious damage to ocean ecosystems.

There are many efforts underway aimed at directly removing carbon dioxide from the air as a way to mitigate the effects of ongoing emissions.  But another possibility is to remove CO2 directly from ocean water.  Existing methods for doing it involve the use of expensive membranes and complex chemicals. The economics of such methods are quite unfavorable.

Recently, a team of researchers at MIT has identified what they claim is a truly efficient and inexpensive removal mechanism. It involves a reversible process based on membrane-free electrochemical cells.  Electrodes in the cells release protons that are introduced to seawater which drive the release of carbon dioxide dissolved in the water. The carbon dioxide can be collected and the processed water ends up being alkaline.

Running this process at a site that is already collecting seawater – such as at a desalination plant – would be an effective way to collect carbon dioxide as well as help mitigate ocean acidification.

Once the carbon dioxide is removed from the water, it still needs to be disposed of, just as is the case for other carbon removal processes.  It could be turned into useful chemicals or it could be stored in underground caverns.  But this approach is fairly unique in that the carbon dioxide has already been captured by the ocean.  The issue remains what to do with it.

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How to pull carbon dioxide out of seawater

Photo, posted January 19, 2016, courtesy of Judy Dean via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cheaper Carbon Capture | Earth Wise

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As the years roll by without sufficient progress in reducing carbon dioxide emissions, the need for technologies that can capture CO2 from its sources or remove it from the air becomes stronger and stronger.  People have developed various ways to capture carbon dioxide, but to date, they generally suffer from some combination of being too costly or not being able to scale up to the necessary magnitude.

Scientists at the Pacific Northwest National Laboratory in Richland, Washington recently announced the creation of a new system that they claim is the least costly to date that captures carbon dioxide and turns it into a widely-used chemical: methanol.

Technologies that simply capture carbon dioxide that then needs to be stored in some secure location are difficult to implement from a cost perspective.  The PNNL researchers believe that turning CO2 into methanol can provide the financial incentive for widespread implementation.   Methanol can be used as a fuel, a solvent, or an important ingredient in plastics, paint, construction materials, and car parts.

The system is designed to be installed in fossil fuel-fired power plants as well as cement and steel plants.  Using a capture solvent developed by PNNL, the system grabs carbon dioxide molecules before they are emitted and converts them into methanol. Creating methanol from CO2 is nothing new, but capturing the carbon dioxide and converting into methanol in one continuously flowing system is new.

More work is needed to optimize and scale the process and it may be several years before it is ready for commercial deployment.

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Scientists Unveil Least Costly Carbon Capture System to Date

Photo, posted November 25, 2022, courtesy of Massachusetts Department of Environmental Conservation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Life In The Great Pacific Garbage Patch | Earth Wise

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The world’s oceans contain five gyres, which are large systems of circular currents created by global wind patterns and the Earth’s rotation.   Gyres act like gigantic whirlpools.  Anything that floats into one of them eventually ends up in the center.   Ever since floating plastic waste started entering the ocean, it has poured into these gyres and created so-called garbage patches.  The largest of these is the Great Pacific Garbage Patch, located halfway between Hawaii and California.  According to the Ocean Cleanup Foundation, the Great Pacific Patch contains at least 79,000 tons of plastic.

A recent study has shown that the garbage patch is not just a place where drifting plastics aggregate; it is also a place where drifting animals aggregate.

It turns out that the Great Pacific Garbage Patch is absolutely teeming with life, primarily small surface-dwelling animals that are collectively known as neuston.  A ship surveying the garbage patch found that in some places, there were nearly as many neuston as there are pieces of plastic.

Typical creatures in the patch are blue dragon nudibranchs, Portuguese man-o-wars, anemones, sea snails, blue buttons (which are related to jellyfish) and hydrozoans.  It appears that these creatures are reproducing within the garbage patch.  Little is actually known about the life history and ecology of these creatures, so that studying the garbage patch is offering valuable insights to scientists.

Two nonprofit organizations are working to remove floating plastic from the Great Pacific Garbage Patch.  Evidently, removing this existing pollution from the ocean is likely to have unexpected effects on the local ecosystem and is a source of at least some controversy.  One thing that isn’t controversial, however, is that we need to stop the flow of plastic into the ocean.

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The Ocean’s Biggest Garbage Pile Is Full of Floating Life

Photo, posted in April, 2012, courtesy of Steven Guerrisi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Primary Ways To Mitigate Climate Change | Earth Wise

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The most recent report issued by the Intergovernmental Panel on Climate Change states that the world must halt the increase in greenhouse gases within three years, reduce emissions by 43% in the next seven years, and eliminate them entirely by 2050.  Otherwise, there will likely be catastrophic and irreversible impacts on the climate.

With respect to achieving these reductions, the report emphasizes decarbonizing the energy sector through electrification by replacing fossil fuels anywhere and everywhere possible.  Where that isn’t yet practical – such as in shipping and aviation – the use of biofuels and hydrogen can provide a stopgap until battery technology becomes a viable alternative.

The economics of this approach continue to improve.  Since 2010, the cost of wind, solar, and batteries has declined by as much as 85%.  In many cases, costs have fallen below those of fossil fuels.  Nonetheless, the report stresses that continuing to provide national, state, and local incentives for using renewable energy is a key factor in achieving the necessary reductions.

However, reducing emissions will no longer be enough.  This is the first major IPCC report that states that man-made carbon dioxide removal strategies will be necessary to meet the goals of the Paris Climate Agreement.  So-called natural carbon storage options, like planting trees and using farming methods that sequester carbon in soil, are also important parts of the strategy.

It is up to governments, policymakers, and investors to implement the necessary changes to mitigate climate change.  There is lots of talk about it, but it will take concerted action to avoid increasingly dire consequences.

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Report highlights affordable, available ways to mitigate climate change now

Photo, posted September 8, 2007, courtesy of Kevin Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Greenhouse Gas Removal And Net Zero | Earth Wise

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Reducing the amount of greenhouse gas emissions can slow the progress of global warming but only reaching and sustaining net zero global emissions can halt the progress of climate change.

The move to renewable power and the use of electric transport are substantial and essential ways to reduce emissions.  But even if these transitions take place on a rapid timescale, they will not eliminate all emissions.  Many industrial activities and, especially, agriculture will continue to contribute substantial greenhouse gas emissions.   There are efforts to reduce the contributions of these things, but there are no zero-emission substitutes for most of them.

As a result, actually removing CO2 from the atmosphere once it is there is essential to achieve net zero emissions.  If greenhouse gas removal can be scaled up sufficiently, it opens the option of going “net negative”, which would be the ideal way to mitigate and, better still, reverse the effects of climate change.

There are multiple approaches to carbon dioxide removal.  Some are natural, involving ways of capturing and storing carbon in trees, biochar, and peatlands.  Others are technological.  An example is the system that has just gone into operation in Iceland that uses fans, chemicals, and heat to capture CO2 and then mineralize it in volcanic rock.   Another is a system being tested in the UK that captures CO2 from growing biomass and pipes it to storage under the North Sea.

Much of the attention on carbon capture technology is aimed at trapping the emissions from fossil fuel power plants, but the need to remove carbon dioxide that has entered the atmosphere in other ways is ultimately far greater.

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CO2 removal is essential to achieving net zero

Photo, posted August 17, 2013, courtesy of Joshua Mayer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Marine Debris | Earth Wise

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Marine debris is a troubling issue around the world.  For most people, it is unsightly and perhaps inconvenient, but for many it is a critical problem that has serious impacts on many aspects of life.  This is especially the case for indigenous communities for whom the natural environment around the ocean is central to subsistence, recreation, culture, and economic opportunities.

The National Oceanic and Atmospheric Administration sponsors a Marine Debris Program that supports multiple projects.  In Alaska’s Pribilof Islands, the indigenous communities of St. George and St. Paul Islands conduct regular cleanups to protect and steward the natural resources that they depend on.  They make use of unmanned aircraft system surveys to target removal and monitoring efforts.

Another NOAA-sponsored program works to clean up the Maybeso Estuary in Alaska’s Prince of Wales Islands.  The project has removed 35,000 pounds of debris, freeing the flow of the salmon stream and restoring the area as a prime hotspot for fishing, boating, and outdoor recreation.

In Washington State’s Olympic Coast, the Makah Tribe has a project to locate and remove derelict crab pots and fishing lines from 80 miles of fishing area and marine sanctuary.  Derelict fishing gear can trap and entangle animals, degrade habitat, imperil navigation, and interfere with fishing.  The project team is working with tribal stakeholders on promoting marine debris awareness.

All of these communities have cared for the environment for generations, but marine debris poses perilous threats to their territories and community action is needed to preserve and protect these remarkable places.

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Lives and Livelihoods Disrupted by Marine Debris

Photo, posted September 11, 2015, courtesy of NOAA’s National Ocean Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Oil Platforms And Fish | Earth Wise

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It is well-known that offshore oil platforms become major habitats for fish.  Their support structures rise hundreds of feet through the water column and basically create a prefabricated reef for marine life.   Many of these platforms will soon be decommissioned and government agencies are considering the consequences to undersea life when this happens.

Researchers at the University of California Santa Barbara have looked at how various decommissioning scenarios would affect undersea ecosystems. They found that completely removing a platform could reduce fish biomass by an average of 95%.  In contrast, removing just the top part of the rig could keep losses to around 10%.

California is looking at several possibilities for decommissioning 27 oil platforms off of its coast.  The three options are:  leave the platform in place, remove all of it, or remove just the top part of it.  Each option entails its own economic and ecological consequences.

The research team studied the size and composition of fish communities at 24 platforms and created models for each of the decommissioning scenarios.  The partial removal approach involved stripping away all structures within 26 meters of the surface.  This number would eliminate the need for a lighted buoy where the support structure remained according to U.S. Coast Guard guidelines.

For the 24 structures studied, leaving them entirely in place would support over 29,000 kilograms of fish biomass.  Removing just the top 26 meters would support nearly 28,000 kilograms.  Removing the platforms entirely would support only 500 kilograms of fish biomass.

As California weighs how to decommission its oil platforms, studies like this will be critical to making informed decisions.

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Oil Platforms’ Fishy Future

Photo, posted June 4, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon Capture As Big Business

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Removing greenhouse gasses from the atmosphere is an essential part of the overall effort to achieve zero net carbon emissions and stabilize the climate.  Since we have not been able to reduce emissions fast enough to do the job, it is important to find ways to pull carbon dioxide out of the atmosphere.

There are many ways to do it, but they tend to be rather expensive and, so far, the need to mitigate climate change does not seem to provide sufficient incentive. A new study by researchers at UCLA, the University of Oxford, and five other institutions, analyzed the possibility of creating a large global industry based on capturing carbon dioxide and turning it into commercial products.

The study investigated the potential future scale and cost of 10 different ways to use carbon dioxide, including in fuels and chemicals, plastics, building materials, soil management, and forestry.  The study looked at processes using carbon dioxide captured from waste products that are produced by burning fossil fuels as well as by simply capturing it directly from the atmosphere.  The study also looked at processes that use carbon dioxide captured biologically by photosynthesis.

The conclusions of the study were that on average each of the ten utilization pathways could use about half a billion tons of carbon dioxide that would otherwise escape into the atmosphere.  Thus, theoretically, these various pathways could take more than five billion tons of CO2 out of the atmosphere.   Currently, fossil fuel combustion emits about 40 billion tons of carbon dioxide.

The authors of the study stress that there is no silver bullet in the fight against climate change.  It will require multiple approaches – including CO2 removal for industrial use – to make real progress

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Carbon dioxide capture and use could become big business

Photo, posted September 18, 2015, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

China And Rare Earth Mining

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Rare earth elements are a crucial part of much of modern technology.  Everything from computers to X-ray machines and aircraft engines needs one or more rare earth elements for magnets, lenses, and other functions.  The world’s tech giants such as Apple, Huawei, and Tesla depend on suppliers of rare earths.

Rare earth elements are not actually rare, but they are very expensive to extract in ways that are not extremely harmful to the environment.  China has been a major source of these elements since its rare earth mining industry took off in the 1990s.  The removal of rare earths from the earth’s crust, using a mix of water and chemicals, has caused extensive water and soil pollution.

Today, concrete leaching ponds and plastic-lined wastewater pools dot the hills of Southeast China.  Large wastewater ponds sit uncovered and open to the elements in many places.  Landslides or barrier failures can spill contaminated contents into waterways or groundwater.

Local and federal officials in China have started to shut down illegal and small-scale rare earth mining operations and have embarked on a cleanup of polluted sites.  The rare earth mining cleanup operation is part of wider efforts across China to address severe problems of water, air and soil pollution.

China’s Ministry of Industry and Information Technology estimated that the cleanup bill for southern Jiangxi Province could amount to more than $5 billion.  Many environmental experts and local officials say that the cost of the cleanup should not be shouldered by the Chinese government alone, but also by the rare earth industry and the global companies and consumers that benefit from rare earth technology.  As rare earth mining efforts start up elsewhere around the world, it is important not to repeat the mistakes made in China.

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China Wrestles with the Toxic Aftermath of Rare Earth Mining

Photo, posted April 21, 2019, courtesy of John Beans via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rigs To Reefs

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There are about 6,000 offshore oil platforms in the world’s oceans.  They have an immense presence physically, financially and environmentally.  As these massive structures extract hydrocarbons from deep beneath the sea, they also undergo a remarkable transformation under the water.  The enormous substructures that support the platforms become vertical reefs, home to millions of individual plants and animals.

Over time, many oil platforms are decommissioned, and their owners are faced with the choice of either removing them entirely or transitioning them into permanent reefs.   Traditional practice was to restore the site to its original condition, but more recently the idea of “reefing” old platforms has gained popularity.  As of 2016, more than 11% of decommissioned platforms in the U.S. portion of the Gulf of Mexico have become permanent reefs.

Decommissioning and completely removing a platform is a daunting and pricey proposition.  The most recent estimate for removing all platforms off the coast of California alone totals $8 billion.  Modifying the platforms to serve as permanent reefs cuts these costs significantly, especially those associated with hauling, cleaning and disposing of the underwater support structure, which will have thousands of tons of sea-life clinging to it by the time it is removed.

Converting the structure into a permanent reef means making it free of any hydrocarbons or other hazardous materials. But this is still a far cheaper venture than total removal.  Studies of oil rigs as underwater habitats have shown them to be some of the most productive in the world.  They are 3-dimensional reefs whose open construction allows currents to pass through bringing lots of nutrients.

Over time, more and more oil platforms will be decommissioned. Many may end up remaining as permanent homes for undersea life.

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Rigs to Reefs

Photo, posted August 21, 2011, courtesy of Marianne Muegenburg via Flickr

Earth Wise is a production of WAMC Northeast Public Radio.

Can We Remove Enough CO2 From The Air?

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As atmospheric carbon dioxide levels continue to set new records and the effects of climate change grow stronger, humanity has continued to procrastinate on reducing emissions.  As a result, it is increasingly clear that any strategy to avoid runaway climate change will have to involve the use of “negative emissions”- techniques or technologies that actually remove CO2 from the air.

There are both low-tech and high-tech methods for removing carbon dioxide from the atmosphere and both are likely to be needed. 

On the low-tech side, afforestation (planting trees where there were none before), reforestation, changes in forest management, rebuilding the carbon backbone in agricultural soils, and the use of energy from waste biomass are all ways to take carbon out of the atmosphere.

On the high-tech side, direct air capture technologies that take CO2 out of the air and store it in the ground are making rapid progress.   Right now, they are still very expensive,but that is changing.  There is an analogy to wind and solar technology. Not very long ago, both of those technologies were quite expensive but now their costs have plummeted to the point where they are often the cheapest way to make electricity.  With sufficient development effort and deployment, direct air capture technology could become quite affordable.

Some people advocate geoengineering as a solution for climate change.  While removing carbon dioxide amounts to tackling the root cause of the warming climate,geoengineering would address the problem by changing the climate again in some other way.  It is at best an extremely dangerous approach.

Removing CO2 using a combination of natural and man-made techniques is an important part of mitigating the effects of climate change.

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Climate Solutions: Is It Feasible to Remove Enough CO2 from the Air?

Photo courtesy of Climeworks. 

Earth Wise is a production of WAMC Northeast Public Radio.

Reviled Animals Can Be Beneficial

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Predators and scavengers are widely persecuted by people because they are often harmful to property, livestock, and human beings.  Nonetheless, research has shown that many of these animals play important roles in ecosystems and their removal can be quite harmful.

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