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According to
the Union of Concerned Scientists, human-induced global
warming is underway right now—and the evidence shows that
landfills are a major contributor to these ominous climatic
changes. Carbon dioxide produced during fossil fuel
combustion (including waste incinerator) is the main culprit
in global warming, but methane also plays a very important
role. The number-one source of human-caused methane
emissions is buried waste. Methane is a potent greenhouse
gas, 21 times more effective at trapping radiant heat than
carbon dioxide. This potency means that landfills contribute
10% of the gases that are warming the globe. Even worse,
when landfilling, incineration, and the extractive
industries are all taken together, our wasteful
nature-to-landfill system accounts for fully 25% of our
society’s greenhouse gas emissions.
Methane is produced in a landfill when the organic materials
like paper, yard debris, wood, and food waste undergo
anaerobic decomposition—a process that shouldn’t be confused
with the oxygen-dependent aerobic process that breaks downs
the fruit rinds and leaves in your backyard composter. As a
result of anaerobic decomposition, the methane gas seeps to
the surface, enters the lower atmosphere, and in concert
with carbon dioxide and other gases, creates a warming
blanket that retains solar infrared radiation and warms the
earth.
Methane Controls Inadequate
Many landfills use gas capture systems to control emissions.
But according to the U.S. Environmental Protection Agency
(which currently subsidizes gas capture efforts through
their Landfill Methane Outreach Program), these systems are
only partially effective, capturing just 20-25% of total
methane emissions. In addition, gas capture subsidies (and
other federal subsidies to the landfill and incineration
industries) can serve to prompt the further burying of
resources; why not feed the landfill if it is a good source
of usable gas? Well, one good reason is that the gas
produced by landfills includes toluene, benzene, and other
toxic gases. These could be avoided altogether if more
cities and states prohibited the landfilling of organics in
the first place.
The current waste industry response to the landfill gas
problem is to champion so-called “bioreactor” landfills. In
contradiction to the “dry tomb” landfill philosophy of the
early 1990’s, water is intentionally pumped into bioreactor
landfills to accelerate the decomposition of organics and
speed production of methane gas. But bioreactor landfills
are fraught with technical problems. Most importantly, there
is no controlling the chemical reactions that result when
organic material interacts with the hazardous waste in the
landfill. Also, the energy captured from landfill gases is
much less than the energy saved by composting or recycling.
This is yet another reason to keep organics out of the
landfill in the first place.
The Solution: Keeping Organics
Out of Landfills
By eliminating the organics that we send to the landfill
through better source prevention, recycling and composting
programs, we can limit our landfill methane problem.
Legislation is one part of the solution. In Norway, for
example, some of the environmental costs of landfills are
accounted for by a law that requires landfills to charge no
less than $100 per ton for burying waste. Here in the U.S.,
the state of Wisconsin has implemented a ban on landfilling
yard waste, corrugated cardboard, newspaper, and
magazines—all organic materials. In Colorado, we lag behind
Wisconsin and many other states. With some of the lowest
landfill fees in the nation (just $15/ton, on average) and
no legislation banning materials from the landfill,
Coloradoans have the go-ahead for burying recoverable
resources like paper and toxic materials like electronic
equipment and batteries.
The phenomenon of human-induced climate change is a complex
one, and eliminating the contribution made by U.S. landfills
alone won’t solve the problem. Still, by taking a Zero Waste
approach we can focus on addressing the concerns that worsen
the landfill crisis. This approach includes: changing
wasteful product and packaging design; creating reuse,
recycling, and composting infrastructure; reducing product
and packaging toxicity; accounting for the real
environmental damages involved in making goods from virgin
resources; and ending subsidies for the wasting industries.
By keeping organics out of the landfill and supporting Zero
Waste enterprises, we can reduce the impact these materials
have on the rate of global climate change. That’s good for
us, our children, and the planet.
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