High tunnels are extensions of the fossil fuel supply
line. The plastic covering
requires barrels of petroleum and therms of natural gas for feed stock and the
energy to manufacture. The support
structure, whether plastic, aluminum or steel, requiring energy for manufacture
and energy for mining in the cases of aluminum and steel. All require transportation and
auxillary energy for storage and installation.
High tunnels are industrial gardening. They are not sustainable, they are not
green, they are not environmentally safe.
“Polyethylene covers on high tunnels and greenhouses make a
significant contribution to the growing problem of waste plastics. . . . Most of
these plastic films are produced from low-density
polyethylene (LDPE #4) resins.”
For a round style high tunnel – 20’ wide x 12’ high x 48’
long – it takes approximately 50 ft of 40 ft wide of 6 mil, 4 year plastic.
Email quote from Kenneth A. Erha
Specialist, Engineering Services & Products Company for FarmTek.com,
TekSupply.com, GrowersSupply.com, and ClearSpan.com This weighs approximately 56 pounds. From data at Plastics Europe this can
be figured to be at least a couple of barrels of crude oil every four years.
It is important to understand that high tunnels do not offer
a sustainable alternative in a world where access to oil and natural gas are
requiring more and more energy to extract. In a world where obtaining fossil fuels requires more and
more environmentally dangerous practices; coal included with the removal of
mountain tops. This does not even
consider the carbon and other greenhouse gas emission required for the
materials, manufacture, transportation and installation of high tunnels.
My point is not to negate the use of high tunnels as much to
require honesty in the promotion of them.
High tunnels as industrial gardening is not a sustainable
answer to our food needs. It is a
side ways move to business as usual.