EarthTalk: Has anyone calculated the energy wasted
at night by unnecessary lighting in and around buildings?
What can we do to reduce our light footprint?
federally funded National Optical Astronomy Observatory
reports that poorly-aimed, unshielded outdoor lights
waste 17.4 billion kilowatt-hours of electricity
in the U.S. each year.
© Brand X Pictures
do squander a lot of electricity keeping things lit up at
night while most of us sleep. This light blocks our view
of the night sky and stars, creates glare hazards on roads,
messes with our circadian sleep-wake rhythms, interrupts
the patterns of nocturnal wildlife, and is by and large
annoying. It also takes a financial toll: The federally
funded National Optical Astronomy Observatory (NOAO) reports
that poorly-aimed, unshielded outdoor lights waste $2 billion
(17.4 billion kilowatt-hours) of energy in the U.S. each
NOAO has monitored
outdoor lighting levels across the U.S. and beyond for the
past six years through its GLOBE at Night program whereby
citizen-scientists track nearby outdoor lighting levels
over a two-week period beginning in late March and submit
their observations to NOAO electronically. A simple star
map provided by NOAO is all that participants need to track
their slice of sky. All it takes is a few minutes
for a family to measure their night sky brightness by noting
how many stars are missing from an easy-to-find constellation
like Leo (in the northern hemisphere) or Crux (in the southern
hemisphere), says GLOBE at Night project director
Connie Walker. This tells us how much light is directed
upwards into the sky.
Over the last
six annual campaigns, participants from 100-plus countries
have contributed almost 70,000 measurements, giving project
organizers a detailed picture of light pollution globally.
Unfortunately, analysis of the data shows that participants
have seen brighter skies and fewer stars over time, meaning
that light pollution is a growing problem. The free and
publicly-accessible data gathered by the project is not
only useful for educational purposes but can also help inform
planners and policymakers on decisions about increasing
public safety, reducing energy consumption and even identifying
parks and green spaces that can serve as sky oases
where city dwellers can appreciate the night sky from a
safe, dark place.
the McDonald Observatorys Dark Skies Initiative (DSI),
the solution to light pollution is 90 percent education
and 10 percent technology. We can reclaim vast amounts
of energy currently wasted inadvertently into the night
by using light fixtures that are shielded to reflect
light down where it is needed, as well as using the smallest
number of lights and lowest wattage bulbs necessary to effectively
light an area, says DSI. Leading by example through
the installation of downward-pointing outdoor light fixtures
is a great place for home and building owners to start:
Once people see it in action, and understand its implications
for cost savings and enhanced visibility, they are far more
likely to adopt good lighting practices on their own.
Another group committed to reducing light pollution, the
International Dark-Sky Association, maintains a list of
distributors that sell approved fixtures to prevent light
Some cities have
instituted standards to limit outdoor night lighting to
protect citizens against unwanted light (or light
trespass). The International Dark-Sky Association
has developed a set of model lighting ordinances that cities
and towns can adopt and modify to suit their needs accordingly.
Also, the U.S. Green Building Council has incorporated a
credit for buildings seeking to reduce the amount of light
trespass and sky glow through its Leadership in Energy and
Environmental Design (LEED) program.
At Night; Dark
Skies Initiative; International
Dark Sky Association.
I read that CO2 in our atmosphere is now more than 300
parts per million. Doesnt this mean that were
too late to avoid the worst impacts of climate change?
amount of carbon dioxide (CO2) in the atmosphere today is
roughly 390 parts per million (ppm). And thats not
good news. Experts agree that this level cannot be
sustained for many decades without potentially catastrophic
consequences, reports the Geos Institute, an Oregon-based
non-profit and consulting firm that uses science to help
people predict, reduce and prepare for climate change.
unlikely to get atmospheric CO2 concentrations down as low
as they were (275 ppm) before we started pumping pollution
skyward during the Industrial Revolution, climate scientists
and green leaders agree that 350 ppm would be a tolerable
upper limit. Prior to 2007 scientists werent sure
what emissions reduction goal to shoot for, but new evidence
led researchers to reach consensus on 350 ppm if we wished
to have a planet, in the words of NASA climatologist James
Hansen, similar to the one on which civilization developed
and to which life on earth is adapted.
350.org, launched in 2008 by writer and activist Bill McKibben
and others to raise awareness about global warming, has
circled the proverbial wagons around the cause of reducing
atmospheric CO2 to 350 ppm. The group has enlisted the help
of thousands of student volunteers around the world to mobilize
public support for reducing humanitys carbon footprint.
1989 book The End of Nature detailed the potential effects
of climate change and remains one of the most influential
environmental books of all time, believes that 350 ppm is
attainable. Were like the patient that goes
to the doctor and learns hes overweight, or his cholesterol
is too high. He doesnt die immediatelybut until
he changes his lifestyle and gets back down to the safe
zone, hes at more risk for heart attack or stroke,
says McKibben. The planet is in its danger zone because
weve poured too much carbon into the atmosphere, and
were starting to see signs of real trouble: melting
ice caps, rapidly spreading drought. We need to scramble
back as quickly as we can to safety.
back will entail nothing short of transforming our
energy infrastructure, including how we transport people
and goods and power our structures. According to 350.org,
it means building solar arrays instead of coal plants, planting
trees instead of cutting forests, increasing energy efficiency
and reducing waste. Getting to 350 means developing
a thousand different solutionsall of which will become
much easier if we have a global treaty grounded in the latest
science and built around the principles of equity and justice,
the group reports. To get this kind of treaty, we
need a movement of people who care enough about our shared
global future to get involved and make their voices heard.
The group is
working to create an international grassroots movement to
influence political dynamics and implement solutions that
show the benefits of moving to a clean energy economy. 350
ppm, while merely a number, represents humanitys potential
capacity to solve the most pressing problem it has faced;
it also represents a target for international negotiators
to aim for in forging an effective global warming treaty.