When we think of climate change deniers, tea partiers and republicans often come to mind. But some of the most troubling stumbling blocks to reducing greenhouse gases come from urban liberals and left-leaning environmental groups who oppose burning municipal solid waste to produce energy.
In California, when new Waste To Energy plants (WTEs) are proposed, they run into buzz saws of liberal opposition. Consequently, California leads the nation in landfilling, at 28 million tons. Plans to increase the volume of waste burned at a Minneapolis WTE facility have been blocked for four years, and the issue recently divided the Democratic candidates for mayor. So they landfill the extra instead. From New York to Massachusetts to Rhode Island to Pennsylvania to Maine, opposition has delayed or stopped WTE plants across the nation, largely in liberal-controlled urban areas.
But the opposition is misguided. Today's Waste To Energy plants (WTEs) are not your granddaddy's trash burners, and some liberal groups, like the Center for American Progress, are starting to look at the actual science and reevaluate long-held assumptions in light of new information and increasing concern over climate change. When they do, they are finding that today's Waste To Energy plants look surprisingly good for the environment and for fighting climate change.
How Waste To Energy Plants Work
Source: Covanta Energy, one of the two major US WTE operators.
Reduce, reuse, recycle--and then what?
Americans generate about 390 million tons of trash every year--as much as 7 pounds per day for every man, woman and child. The problem ranks with energy, food, population and the economy as one of the biggest issues humans need to tackle to create a sustainable world. The US recycles and composts about 94 million tons of that waste, or roughly 24%, but could do much, much more.
Even if the US doubled its rate of recycling, there would still be hundreds of millions of tons of post-recycled, post composted solid waste. What you do with it is the question, and there are two options: dump it in a landfill or burn it/gasify it for energy.
Liberals, overwhelmingly, are choosing to dump, which science shows is the most polluting alternative. Because of liberal opposition, almost no WTEs have been built in the United States for twenty years, despite the science-based classification of WTE as clean or renewable energy by the EPA and 31 state environmental agencies.
Things are very different in green-conscious Europe. While the US has just 89 WTE facilities, Europe has 420 and is building more. Northern Europe, the most environmentally-conscious part of the continent, is also where the most WTEs are located.
WTE construction in the US is being held back by fears that burning trash will cause people to reduce their recycling effort or will put dangerous toxins into the environment. But are those fears supported by the evidence?
Evidence shows recycling and WTE are complimentary
It is certainly true that maximum recycling effort should be put in to remove all recyclables and compostables before the remaining waste is disposed of in a landfill or a WTE facility. But the worry that WTEs reduce recycling rates does not appear to be borne out by the evidence, which shows that to the contrary, they tend to be associated with increased recycling effort.
The five European nations with the highest recycling rates--Germany, the Netherlands, Austria, Belgium, and Sweden--also have among the highest WTE usage, to the point that they have reduced landfill use to less than one percent of their waste. Sweden even competes to import waste. While this is questionably desirable, it does not appear to have reduced their recycling effort, which is higher than the twenty two other European nations.
In America, by contrast, where environmental groups frequently portray the issue as an either/or choice between recycling and WTEs, both rates are much lower, and a whopping 69 percent of US municipal solid waste winds up in landfills.
As in Europe, the trend of increased recycling rates in communities that use WTE also holds in the US, where communities that have a WTE plant show higher recycling rates than the national average.
Finally, recycling itself is not without waste. For example, recycling mixed paper leaves a 15 percent residue that itself has to be disposed of somehow.
Clearly, recycling and WTE can and do go hand-in-hand in a responsible waste management plan, and co-promotion by environmental groups would likely increase both WTE and recycling, both of which are preferable to landfilling in the waste management hierarchy.
Clean air technology cuts emissions to near-zero
While trash burners once did put dangerous toxins into the air, in the last ten years WTE pollution control technology has become so advanced that the most common and dangerous toxins have been almost completely eliminated, something that the environmental groups who still oppose WTEs rarely mention.
Under the Clean Air Act, WTE facilities are required to be equipped with the most modern air pollution control technology available to ensure that smokestack emissions are safe for human health and the environment. This new equipment must meet or exceed the EPA's Maximum Achievable Control Technology (MACT) Standards. WTE plant emissions are far below the limits the EPA set as safe, and get better all the time.
The Minneapolis WTE facility, for example, uses the following process to control their emissions:
- Air is injected into the boiler to control nitrogen oxide emissions.
- Activated carbon is injected into the exhaust gases to control mercury.
- Flue gases then pass through a dry scrubber, where a lime slurry is injected to control sulfur dioxide and hydrochloric acid.
- Combustion gases pass through a bag house containing a series of fabric filters to remove particulate matter (ash), metals and dioxins.
Emissions are monitored on a continuous basis for multiple pollutants.
Using the antiscience playbook
Another common tactic is to use EPA data stating that trash burning is the largest source of cancer-causing dioxins. This is true, but the data refer to the uncontrolled backyard barrel burning of trash, and specifically not to WTEs.
These are the sort of antiscience tactics--quoting old data, misattributing data or results, cherry picking data--that have been used by climate change deniers.
Testing shows the ash to be non-toxic and it is widely used
WTEs reduce the volume of trash by about 90 percent, leaving about 10 percent in the form of ash that still needs to be landfilled unless it can be used elsewhere. Opponents often argue that the ash is toxic, but the EPA developed a test called the Toxicity Characteristic Leaching Procedure that tests the ash with an acidic liquid, causing any of forty identified contaminants, or reactive metals such as cadmium, to leach out. If these metals are found in amounts greater than a fraction of a percent, the ash is considered hazardous. Scientists have tested ash from every WTE facility in the country over the course of several years, and the tests have consistently shown that the ash is non-hazardous.
Consequently, about 3 million tons of concrete-like ash, or more than one-third of all WTE residue, are being reused annually as roadbed material, as daily and final landfill cover, as an aggregate in road construction, as an additive to asphalt, in the construction of artificial reefs, and in cement blocks. WTE operators are actively looking for other ways to reuse the concrete-like ash renewably instead of disposing of the balance in landfills. Mixing it into concrete is one solution that offsets the production of cement, which otherwise accounts for 5% of the world's carbon emissions.
The big one: WTEs fight climate change
Burning trash puts large amounts of carbon dioxide into the atmosphere. And the atmosphere is already at a dangerously high 400 parts per million of carbon dioxide--higher than it has been in at least 600,000 years. 350 parts per million is the maximum level many climate scientists consider safe and sustainable, which is still considerably higher than the roughly 290 ppm it was at the beginning of the industrial revolution.
Classed as low-carbon, renewable energy. But it turns out that while WTEs do emit greenhouse gases, they emit far fewer GHGs on a ton-for-ton basis than America's current practice of landfilling. In fact, 31 state pollution control agencies and two US territories now class WTEs as renewable energy and as preferable to landfilling. To understand why, consider a ton of post-recycled, post-composted trash in either of two scenarios: landfilled, or burned for energy with pollution capture technology.
Half of post-recycled MSW is part of the carbon cycle already. First, roughly 53 percent of post-recyled, post-composted trash is still derived from organic materials and so is part of Earth's carbon cycle anyway. Burning it does not increase the atmosphere's carbon load.
One ton MSW burned prevents one ton GHGs. Burning the remaining 47 percent, which is derived from petroleum carbon, prevents other, worse emissions. According to the EPA, every ton of garbage processed at a WTE facility actually prevents approximately one ton of emitted carbon-dioxide equivalent from going into the atmosphere.
Methane is a far worse GHG. One way this happens is by reducing landfilling. Landfills are the US's largest emitter of methane, a very potent greenhouse gas. According to the United Nations Intergovernmental Panel on Climate Change's Fourth Assessment on Climate Change, in a 20-year window methane is 72 times more potent a greenhouse gas than cardon dioxide. Capped landfills now have the technology to capture methane, but only about 34 percent of that methane is actually used to generate electricity. The rest leaks away or is flared off, and nothing at all is captured for the first few decades that a landfill sits open while being filled.
Metal recycling is built in to WTE. Next, post-recycled trash still contains millions of tons of metals that are sent to landfills. At a WTE facility, those metals are automatically reclaimed and recycled as a part of its normal filtration process. This saves the time, materials, energy, emissions and environmental disruption of mining for an equivalent amount of new minerals. The WTE operator Covanta Energy recycled 415,000 tons of ferrous and 16,800 tons of non-ferrous metals in 2012 alone--enough steel to build 28 Brooklyn Bridges and and enough aluminum to produce over one billion beverage cans.
The aluminum that is reclaimed by WTEs from the already post-recycled waste is particularly important. Recycling one ton of aluminum prevents a whopping 13.7 tons of GHG emissions, compared to 4.3 tons for office paper and 2.5 tons for newspaper. Recycling a ton of ferrous metal prevents 1.7 tons of GHG emissions. None of this is recaptured when a truck tips its load into a landfill.
Cutting waste transportation cuts carbon. WTE facilities are sited close to where the waste is generated, in or near urban areas. This eliminates much of the carbon emitted by hauling waste to a distant landfill. In 2011, New York City spent more than $300 million transporting its trash by train and truck-- roughly 12,000 tons a day--to landfills as far as 300 miles away, emitting tons more carbon and wearing down roads and vehicles in the process. In some cases, such as e-waste, the US is now even exporting its waste to third world countries, vastly compounding its carbon contribution.
Energy generated offsets fossil fuels. WTE facilities generate heat and electricity, reducing the burning of fossil fuels for those same purposes. For example, the Minneapolis WTE facility currently generates enough electricity to power 25,000 homes, and enough steam to heat 1,500. Their proximity also means less heat and electricity are lost in transit.
Lower carbon than fossil fuel. According to the EPA burning municipal solid waste (MSW) in WTEs emits less carbon dioxide per megawatt hour than fossil fuels, including natural gas.
New gasification technologies coming online promise even greater energy capture and lower emissions than WTE by incineration.
Cleaning up U.S. lakes and rivers
Leachate is a hazardous tea created when rain percolates through garbage. Landfills capture this leachate and pump it to a treatment facility, where pollutants are removed through biological and chemical processes, then it is discharged into public waterways. But these treatment facilities rarely have the expensive reverse osmosis filters necessary to capture pharmaceuticals and other bioactive chemical products. These agents are turning up in groundwater throughout the United States and polluting even remote lakes and rivers. Their presence affects fish and other aquatic species, and they are now found in several municipal water supplies that are drawn from pharmaceutically polluted waters.
WTE facilities provide a safe way to destroy pharmaceuticals and other bioactive products that are disposed of in landfills or that people flush down the toilet. The high temperature of WTE combustion completely destroys the chemicals, rendering them inactive and ensuring cleaner lakes, rivers, and human water supplies and less pharmaceuticals and bioactive agents entering the food chain and affecting public health.
The times they are a changin'
So with all these benefits--efficiency, clean energy, reduced greenhouse gases, reduced transportation and road repair, reduced mining, freeing green space otherwise used for landfills, protecting groundwater and public waters, keeping the food chain cleaner, recycling metals--why haven't US liberals, who control the politics in many metropolitan areas where WTEs should be being built, been all over them like they have been in Europe? The answer lies in the history of the American public's views toward science.
Suspicion of corporations and of hidden dangers to health or the environment have become core and often unquestioned assumptions of the liberal US politics that grew up out of the birth of environmental science and the environmental movement. But these days there is a growing rift between the science and the movement in areas related to energy, climate and waste management. While liberals are justified in their concern about the hidden dangers that pollution can pose to health and the environment, in the case of Waste To Energy plants that view has not kept pace with the facts. This has led them to adopt policies that are less effective than other countries when it comes to managing waste and fighting climate change.
It's time for a change. American liberals and environmentalists who care about climate change need to reexamine the science and get behind expanded recycling and waste to energy programs. Fortunately for the sake of our children, a few bold leaders are starting to do just that.
A version of this article also appears on Ensia.com.
Shawn Lawrence Otto is a science writer, filmmaker, novelist, and the co-founder of ScienceDebate.org, the home of the US presidential science debates. His new book is Fool Me Twice: Fighting the Assault on Science in America. He lives in a wind-powered, passive solar, superinsulated geothermal home he designed and built with his own hands. He recycles, composts and drives a hybrid car. Visit him at www.shawnotto.com and like him on Facebook. Join ScienceDebate.org to get candidates to debate science issues.
Wakati tunapofikiria wakataa mabadiliko ya hali ya hewa, waandamanaji wa chai na Republican mara nyingi huja akilini. Lakini baadhi ya vikwazo vikali zaidi kwa kupunguza gesi za chafu zinatoka kwa wakurugenzi wa mijini na vikundi vya kimazingira vya kushoto vinavyopinga kuchoma taka ngumu za manispaa ili kuzalisha nishati. Katika California, wakati mpya Waste To Energy mimea (WTE) ni mapendekezo, wao kukimbia katika buzz saws ya upinzani huria. California inaongoza katika kutupa taka kwa tani milioni 28. Mipango ya kuongeza kiasi cha taka zinazowashwa katika kituo cha WTE cha Minneapolis imezuiwa kwa miaka minne, na suala hilo hivi karibuni liliwagawanya wagombea wa Democrat kwa meya. Kwa hiyo wao huteka hazina ya ziada badala yake. Kutoka New York hadi Massachusetts, Rhode Island, Pennsylvania hadi Maine, upinzani umechelewesha au kusimamisha mitambo ya WTE kote nchini, haswa katika maeneo ya mijini yanayodhibitiwa na uhuru. Lakini upinzani umepotoka. Waste-to-energy (WTE) ni aina ya mashine ya kutengeneza nishati ambayo inaundwa na wanasayansi wa kisasa, na inaundwa na Shirika la Maendeleo ya Amerika (Center for American Progress) na inaonyesha kuwa hali ya hewa inabadilika kwa kasi zaidi. "Wakati wanafanya hivyo, wanagundua kwamba mitambo ya leo ya ""kuondoa taka na kutengeneza nishati"" inaonekana kuwa nzuri kwa mazingira na kupambana na mabadiliko ya hali ya hewa." Waste-to-energy (WTE) ni moja ya makampuni makubwa ya umeme nchini Marekani. Kupunguza, kutumia tena, kuchakata - na kisha nini? Wamarekani hutengeneza takriban tani milioni 390 za taka kila mwaka - karibu pauni 7 kwa siku kwa kila mwanamume, mwanamke na mtoto. "Tatizo hili linashikamana na nishati, chakula, idadi ya watu na uchumi kama moja ya masuala makubwa ambayo wanadamu wanahitaji kushughulikia ili kuunda ulimwengu endelevu.""" Marekani inazalisha na kuharibu takriban tani milioni 94 za taka, lakini inaweza kufanya mengi zaidi. Hata kama Marekani ingeongeza kiwango chake cha kuchakata mara mbili, bado kungekuwa na mamia ya mamilioni ya tani za taka ngumu baada ya kuchakata na baada ya kuyeyusha. "Kuna njia mbili za kufanya hivyo: kutupa katika mahali pa kuondoa taka au kuichoma kwa ajili ya nishati.""" Wafuasi wa uhuru, kwa wingi, wanachagua kutupa, ambayo sayansi inaonyesha ni mbadala wenye uchafuzi zaidi. Kwa sababu ya upinzani wa uhuru, karibu hakuna WTE zilizojengwa nchini Marekani kwa miaka ishirini, licha ya uainishaji wa sayansi wa WTE kama nishati safi au mbadala na EPA na mashirika 31 ya mazingira ya serikali. Mambo ni tofauti sana katika Ulaya yenye fahamu ya kijani kibichi. Marekani ina vituo vya WTE 89 tu, Ulaya ina 420 na inajenga zaidi. Ulaya ya Kaskazini, sehemu yenye ufahamu zaidi wa mazingira ya bara hilo, pia ni mahali ambapo WTEs nyingi ziko. Ujenzi wa WTE nchini Marekani unazuiwa na hofu kwamba kuchoma takwimu kutasababisha watu kupunguza juhudi zao za kuchakata au kutatoa sumu hatari katika mazingira. Lakini je, hofu hizo zinaungwa mkono na uthibitisho? """Uhakika unaonyesha kuwa kuchakata na WTE ni ziada, ni kweli kwamba juhudi za juu za kuchakata zinapaswa kuwekwa ili kuondoa vitu vyote vinavyoweza kuchakata na kuunganishwa kabla ya taka zilizobaki kutupwa katika mahali pa kuondoa taka au kituo cha WTE." Lakini wasiwasi kwamba WTE hupunguza viwango vya kuchakata haionekani kuwa na ushahidi, ambayo inaonyesha kwamba kinyume chake, huwa na kuhusishwa na juhudi za kuchakata zilizozidiwa. Nchi tano za Ulaya zilizo na viwango vya juu zaidi vya kuchakata - Ujerumani, Uholanzi, Austria, Ubelgiji, na Sweden - pia zina kati ya matumizi ya juu zaidi ya WTE, hadi hatua ambayo wamepunguza matumizi ya takwimu ya taka hadi chini ya asilimia moja ya taka zao. Sweden hata inashindana kuagiza taka. Ingawa hii ni ya kutiliwa shaka, haionekani kuwa imepunguza juhudi zao za kuchakata, ambazo ni za juu kuliko mataifa mengine ishirini na mawili ya Ulaya. Kwa upande mwingine, katika nchi za Ulaya, ambapo makundi ya mazingira mara nyingi kuelezea suala kama ama au uchaguzi kati ya kuchakata na WEEE, viwango vyote ni chini sana, na whopping 69% ya taka ya mji wa Marekani mwisho katika majumba ya taka. Kama ilivyo katika Ulaya, mwenendo wa kuongezeka kwa viwango vya kuchakata katika jamii ambazo hutumia WTE pia unashikilia nchini Marekani, ambapo jamii ambazo zina kiwanda cha WTE zinaonyesha viwango vya kuchakata vya juu kuliko wastani wa kitaifa. Mwishowe, kuchakata vitu hakukuwa bila taka. Kwa mfano, kuchakata karatasi huondoa asilimia 15 ya mabaki ambayo yanapaswa kuondolewa. Kwa kweli, WEEE na WEEE zinaweza na zinaenda mkono kwa mkono katika mpango wa usimamizi wa taka, na kukuza kwa pamoja na makundi ya mazingira kunaweza kuongeza WEEE na usindikaji, ambayo yote ni bora kuliko kutupa taka katika utaratibu wa usimamizi wa taka. Teknolojia ya hewa safi hupunguza uzalishaji wa gesi karibu na sifuri, wakati wazimaji wa taka walipokuwa na sumu hatari katika hewa, katika miaka kumi iliyopita teknolojia ya kudhibiti uchafuzi wa mazingira imekuwa ya hali ya juu sana kwamba sumu za kawaida na hatari zimepunguzwa kabisa, kitu ambacho vikundi vya mazingira vinavyopinga WTE bado havitajwi. Kwa mujibu wa Sheria ya Hewa Safi, vituo vya WTE vinapaswa kuwa na vifaa vya kisasa zaidi vya kudhibiti uchafuzi wa hewa ili kuhakikisha kwamba uzalishaji wa moshi ni salama kwa afya ya binadamu na mazingira. Vifaa hivi vinapaswa kukidhi au kuzidi viwango vya EPA vya Teknolojia ya Udhibiti ya Kiwango cha Juu (MACT). "WEEE inazidi ""kufikia kiwango cha usalama"" ambacho EPA imeweka, na inazidi kuwa bora zaidi." Kwa mfano, kituo cha WTE cha Minneapolis hutumia mchakato ufuatao kudhibiti uzalishaji wao: - Hewa huingizwa ndani ya boiler kudhibiti uzalishaji wa oksidi ya nitrojeni. - Makaa ya mawe yenye nguvu huingizwa katika gesi za kutolea nje ili kudhibiti zebaki. - Gesi za moshi kisha hupita kupitia scrubber kavu, ambapo lime slurry ni injected kudhibiti sulfuri dioksidi na asidi hydrochloric. - Gesi ya mwako hupita kupitia nyumba ya mfuko yenye mfululizo wa vichungi vya kitambaa ili kuondoa chembechembe (mvua), metali na dioksini. Utoaji ni kufuatiliwa juu ya msingi wa kuendelea kwa ajili ya uchafuzi mbalimbali. "Kutumia ""kitabu cha michezo cha anti-sayansi"" ni mbinu nyingine ya kawaida ya kutumia takwimu za EPA ambazo zinasema kwamba kuchoma taka ni chanzo kikubwa cha dioksini zinazosababisha kansa." Hii ni kweli, lakini data inahusu kuchoma taka bila kudhibitiwa, na haswa sio kwa WTE. Hizi ni aina ya mbinu za kupambana na sayansi - kunukuu data za zamani, kutoa data au matokeo vibaya, data ya kuchagua cherry - ambazo zimetumiwa na wakataa mabadiliko ya hali ya hewa. Kwa mfano, WTE ni sumu na haina sumu, na inasaidia kupunguza kiasi cha taka kwa asilimia 90, na inaacha asilimia 10 kama majivu ambayo bado yanahitaji kuhifadhiwa isipokuwa inaweza kutumika mahali pengine. "Wakati mwingine, kama vile kwa mfano, EPA ina ""toxicity characteristic leaching procedure"" ambayo inahakikisha kwamba kemikali yoyote ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali ya kemikali." Ikiwa metali hizo zinapatikana kwa kiasi kikubwa kuliko sehemu ndogo ya asilimia moja, majivu hayo huonwa kuwa hatari. Wanasayansi wamekuwa wakichunguza majivu kutoka kwa kila kituo cha WTE nchini humo kwa miaka kadhaa, na majaribio hayo yameonyesha mara kwa mara kwamba majivu hayo hayana hatari. Kwa hivyo, karibu tani milioni 3 za majivu ya saruji, au zaidi ya theluthi moja ya mabaki yote ya WTE, hutumiwa tena kila mwaka kama nyenzo ya barabara, kama kifuniko cha kila siku na mwisho cha kutupa taka, kama mchanganyiko katika ujenzi wa barabara, kama nyongeza ya lami, katika ujenzi wa miamba ya bandia, na katika mabaki ya saruji. WTE inaendelea kutafuta njia za kutumia tena majivu ya saruji badala ya kuondoa mabaki katika majumba ya taka. Kuchanganya na saruji ni suluhisho moja ambayo hupunguza uzalishaji wa saruji, ambayo kwa njia nyingine inawakilisha asilimia 5 ya uzalishaji wa kaboni duniani. WTE: Kupunguza mabadiliko ya hali ya hewa: Kuungua taka inaweka kiasi kikubwa cha kaboni dioksidi katika anga Kwa sasa, angahewa la dunia lina kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi cha kiasi. "Hiyo ni kiwango cha juu ambacho wanasayansi wengi wa hali ya hewa wanaona kuwa salama na endelevu, ambayo bado ni ya juu sana kuliko ""karibu 290 ppm"" ilikuwa mwanzoni mwa mapinduzi ya viwanda." Imeorodheshwa kama nishati ya chini ya kaboni, inayobadilika. Lakini inatokea kwamba wakati WTE hutoa gesi za chafu, hutokeza gesi chache za chafu kwa msingi wa tani kwa tani kuliko mazoezi ya sasa ya Amerika ya kuondoa taka. Kwa kweli, mashirika 31 ya kudhibiti uchafuzi wa mazingira na maeneo mawili ya Marekani sasa yanaorodhesha WTE kama nishati mbadala na kama bora kuliko kuhifadhiwa kwenye majengo ya taka. Ili kuelewa kwa nini, fikiria tani ya taka ya baada ya kuchakata, baada ya kuyeyusha katika moja ya matukio mawili: kuhifadhiwa, au kuchomwa kwa nishati na teknolojia ya kuambukiza. Nusu ya MSW ya baada ya kuchakata tayari ni sehemu ya mzunguko wa kaboni. Kwa mfano, asilimia 53 ya taka zilizotengenezwa baada ya kuchukuliwa na kuzalisha mbolea bado zinatokana na vitu vya kikaboni, na hivyo ni sehemu ya mzunguko wa kaboni ya Dunia. Kuichoma haiongezi mzigo wa kaboni katika angahewa. Toni moja ya MSW iliyowashwa inazuia tani moja ya GHG. Kuungua kwa asilimia 47 iliyobaki, ambayo hutokana na kaboni ya petroli, huzuia uzalishaji mwingine mbaya zaidi. Kulingana na EPA, kila tani ya taka iliyotengenezwa katika kituo cha WTE inazuia karibu tani moja ya kaboni dioksidi inayotokana na kutolewa kwenda angahewa. Methani ni gesi mbaya zaidi ya chafu. Njia moja ya kufanya hivyo ni kupunguza kutupwa kwenye majengo ya kuhifadhia taka. Maeneo ya kuondoa taka ni chanzo kikuu cha gesi ya methane nchini Marekani, ambayo ni gesi yenye athari kubwa ya kutokeza joto. Kulingana na ripoti ya mwisho ya Umoja wa Mataifa ya Panel ya Kati ya Serikali juu ya Mabadiliko ya Hali ya Hewa, methane ni gesi yenye nguvu zaidi ya gesi ya chafu ya carbon dioxide. Maeneo ya kuondoa taka yana teknolojia ya kuondoa metani, lakini ni asilimia 34 tu ya metani hiyo inayotumiwa kutengeneza umeme. Matofali hayo yanavuja au kuwaka moto, na hakuna chochote kinachokamatwa kwa miongo michache ya kwanza ambayo mahali pa kuondoa taka hukaa wazi wakati wa kujazwa. Kwa mfano, kutengeneza chuma kwa ajili ya matumizi ya matumizi ya WEEE ni muhimu. Baadaye, taka zilizotengenezwa upya bado zina mamilioni ya tani za metali ambazo hutumwa kwenye mahali pa kuondoa taka. Katika WTE, metali hizo hutengenezwa upya na kutumiwa tena kama sehemu ya mchakato wa kawaida wa kuchuja. Hii huokoa muda, vifaa, nishati, uzalishaji na usumbufu wa mazingira wa madini kwa kiasi sawa cha madini mapya. Kampuni ya WTE Covanta Energy ilitengeneza tani 415,000 za chuma cha chuma na tani 16,800 za chuma cha chuma katika mwaka 2012 pekee - chuma cha kutosha kujenga madaraja 28 ya Brooklyn na alumini ya kutosha kutengeneza zaidi ya makopo ya vinywaji bilioni moja. Aluminium ambayo ni recycled na WTE kutoka taka tayari baada ya kusindika ni muhimu hasa. Kwa mfano, kuchakata tani moja ya alumini kunazuia kutokezwa kwa gesi ya gesi ya chafu kwa kiasi kikubwa cha tani 13.7, ikilinganishwa na tani 4.3 kwa karatasi ya ofisi na tani 2.5 kwa karatasi ya gazeti. Kwa mfano, kutengeneza tani moja ya chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma cha chuma. Hakuna chochote cha hayo kinachopatikana tena wakati lori linapoelekeza mzigo wake kwenye mahali pa kuondoa taka. Kupunguza usafirishaji wa taka hupunguza kaboni. WEEE ni mahali ambapo taka hutengenezwa, karibu na maeneo ya mijini. Hilo huondoa sehemu kubwa ya kaboni inayotokezwa kwa kubeba taka hadi mahali pa kuondoa taka palipo mbali. Mwaka 2011, New York City ilitumia zaidi ya dola milioni 300 kusafirisha taka zake kwa treni na lori - takriban tani 12,000 kwa siku - hadi kwenye mabwawa ya taka hadi kilomita 300 mbali, ikitoa tani zaidi za kaboni na kuharibu barabara na magari katika mchakato huo. Katika baadhi ya kesi, kama vile taka za elektroniki, Marekani sasa hata inasafirisha taka zake kwa nchi za ulimwengu wa tatu, ikiongeza sana mchango wake wa kaboni. Nishati inayotokezwa hulipia mafuta ya visukuku. WEEE hutengeneza joto na umeme, kupunguza kuchoma kwa mafuta ya mafuta kwa madhumuni hayo. Kwa mfano, kituo cha WTE cha Minneapolis kwa sasa kinazalisha umeme wa kutosha kuendesha nyumba 25,000, na mvuke wa kutosha kupasha joto nyumba 1,500. Ukaribu wao pia humaanisha joto na umeme mdogo hupotezwa katika usafiri. Karboni ya chini kuliko mafuta ya visukuku. Kulingana na EPA, kuchoma taka ngumu za manispaa (MSW) katika WTE hutoa kaboni dioksidi kidogo kwa megawatt saa kuliko mafuta ya mafuta, pamoja na gesi ya asili. Teknolojia mpya za gasification zinazokuja mtandaoni zinaahidi hata kukamata nishati kubwa na uzalishaji mdogo kuliko WTE kwa kuchoma. Mto Leachate ni maji hatari yanayotokana na mvua ambayo huingia ndani ya maji ya taka. Maeneo ya kuondoa taka huchukua maji hayo na kuyapomba kwenye kituo cha kusafisha, ambako uchafuzi huondolewa kupitia michakato ya kibiolojia na kemikali, kisha hutolewa kwenye njia za maji za umma. Lakini vituo hivi vya matibabu mara chache huwa na vichungi vya gharama kubwa vya osmosis ya kurudi nyuma vinavyohitajika kukamata dawa na bidhaa nyingine za kemikali zenye bioactive. Vitu hivyo vimeenea sana katika maji ya chini ya ardhi kote Marekani na vinachafua hata maziwa na mito iliyo mbali. Uwepo wao huathiri samaki na spishi nyingine za majini, na sasa zinapatikana katika maji kadhaa ya manispaa ambayo hutolewa kutoka kwa maji yaliyochafuliwa na dawa. WEEE ni njia salama ya kuharibu dawa na bidhaa nyingine za bioactive ambazo hutupwa katika majumba ya taka au kwamba watu flush chini ya choo. Joto la juu la WTE huangamiza kabisa kemikali, na kuifanya iwe hai na kuhakikisha maziwa safi, mito, na maji ya binadamu, na dawa chache na mawakala wa bioactive kuingia kwenye mlolongo wa chakula na kuathiri afya ya umma. "Kwa hivyo, kwa faida hizi zote - ufanisi, nishati safi, kupunguza gesi za chafu, kupunguza usafirishaji na ukarabati wa barabara, kupunguza uchimbaji madini, kuondoa nafasi ya kijani ambayo ingetumika kwa ajili ya majumba ya taka, kulinda maji ya chini ya ardhi na maji ya umma, kuweka mlolongo wa chakula safi, kuchakata metali - kwa nini wanaharakati wa Marekani, ambao wanadhibiti siasa katika maeneo mengi ya mji mkuu ambapo WTE inapaswa kujengwa, hawajawapata?""" Jibu liko katika historia ya maoni ya umma wa Marekani kuelekea sayansi. Mashaka ya mashirika na hatari zilizofichwa kwa afya au mazingira yamekuwa dhana za msingi na mara nyingi zisizohesabiwa za siasa za huria za Marekani ambazo zilitokana na kuzaliwa kwa sayansi ya mazingira na harakati ya mazingira. Lakini siku hizi kuna mgawanyiko unaoongezeka kati ya sayansi na harakati katika maeneo yanayohusiana na nishati, hali ya hewa na usimamizi wa taka. Ingawa wanaharakati wa haki za binadamu wana haki ya kuwa na wasiwasi kuhusu hatari zilizofichwa ambazo uchafuzi wa mazingira unaweza kusababisha kwa afya na mazingira, katika kesi ya Waste To Energy, mtazamo huo haukufuata ukweli. Hii imesababisha nchi hizo kupitisha sera ambazo hazifanyi kazi kama nchi nyingine wakati wa kusimamia taka na kupambana na mabadiliko ya hali ya hewa. Ni wakati wa mabadiliko. "Wanajamii wa Marekani na wanaharakati wa mazingira ambao wanajali mabadiliko ya hali ya hewa wanahitaji kuchunguza tena sayansi na kupata nyuma ya programu za kupanua ""kurudisha na taka kwa nishati.""" Kwa bahati nzuri kwa ajili ya watoto wetu, viongozi wachache wenye ujasiri wanaanza kufanya hivyo. Toleo la makala hii pia inaonekana kwenye Ensia.com. Shawn Lawrence Otto ni mwandishi wa sayansi, mtengenezaji wa filamu, mwandishi wa riwaya, na mwanzilishi mwenza wa ScienceDebate.org, nyumba ya mjadala wa sayansi wa rais wa Marekani. Kitabu chake kipya ni Fool Me Twice: Fighting the Assault on Science in America. Anaishi katika nyumba ya upepo, ya jua, ya joto la ardhi iliyoundwa na kujengwa kwa mikono yake mwenyewe. Yeye hutumia tena, hutengeneza mbolea na kuendesha gari la hybridi. Tembelea tovuti yetu ya ShotSpot.com na kama yeye kwenye Facebook. Kujiunga na ScienceDebate.org kupata wagombea kujadili masuala ya sayansi.