|
the
environmental crisis
While
the MCV Foundation’s primary goal, through the
DCV Poverty Alleviation Program,
is the alleviation of poverty and through this effort, the eradication
of crime, it has also set its sights on finding solutions to the
environmental crisis, in particular, the accumulation of
Greenhouse Gas Emissions in the earth’s atmosphere
causing global warming resulting to climate change.
History of Air Pollution and the Legislation of Clean Air
 In
the early agricultural ages of mankind, air pollution as we know it
today did not exist. Manmade smoke usually originated from burning wood
used for cooking his food, keeping him warm or to light the night with.
Around the Middle Ages, the use of coal in cities such as London
escalated and even as far back as the 16th Century, poor air
quality in urban areas were documented. The Industrial Revolution of the
18th and 19th Centuries in the United Kingdom
depended heavily on the use of coal as fuel. Factories located inside
towns and cities used large amounts of coal and homes likewise used coal
for heating and cooking. The smoke from these sources combined with fog
resulted in smog (smoke + fog). The smog became so bad at times that
transportation in these cities came to a halt. The dirtying effect of
the air pollution on buildings were clearly noticeable but more than
that, death rates increased. Their 1875 Public Health Act included a
smoke abatement section in an attempt to reduce air pollution in urban
areas. So, long before any formal “Clean Air Act” was even conceived,
there were already moves to reduce air pollution through legislation.
The
1926 Smoke Abatement Act in the UK aimed at industries brought about a
reduction of smog in urban areas. Although in the early part of the 20th
Century, the use of coal was diminishing, air pollution from other
sources like industrial fuel oil were taking its place. In 1952, the
Great London Smog caused an additional 4.000 deaths in the city
resulting in the Clean Air Acts of 1956 and 1968 which formed smokeless
zones in urban areas and a tall chimney policy on factories followed by
later legislation including the 1974 Control of Air Pollution Act.
 In
major cities around the world, it had been observed that air pollution
levels were getting so high that on some days, it was dense enough to
make entire buildings disappear from view. Actually, the increasing
number of motor vehicles in urban areas was the problem, the smog that
was being generated was not really caused so much by smoke but by a
chemical reaction between motor vehicle emissions and sunlight, thus
producing what is known as “photochemical smog”. In the 1980s, concern
of the public health focused on the effects of lead poisoning –
remember, that was the era of leaded gasoline. Medical authorities
connected the rising incidences of lung cancer with urban air pollution
besides heavy tobacco use.
In the
United States, landmark legislation includes the Air Pollution Control
Act of 1955, the Clean Air Act of 1963, the Air Quality Act of 1967 and
the Clean Air Act of 1970, the 1977 Amendments to the Clean Air Act of
1970 and the 1990 Amendments to the Clean Air Act of 1970.
In the
Philippines, Republic Act No. 8749 or the Philippine Clean Air Act of
1999 was established which, as stated therein: “AN ACT PROVIDING FOR A
COMPREHENSIVE AIR POLLUTION CONTROL POLICY AND FOR OTHER PURPOSES”. The
Philippine Clean Air Act became law on June 1999. Its key features
include the following:
-
Development of a national air
quality management framework, and a fund to be earmarked for air quality
management activities.
-
Imposition of air quality
management charges.
-
Improvement in quality of
gasoline and diesel and promotion of alternative, cleaner fuels.
In
compliance to legislations such as the Clean Air Acts, tougher
regulations are enforced on the automotive industry, cleaner fuel
compositions have been introduced (leaded gasoline being phased out),
stricter motor vehicle emission standards established, etc. Also,
industries are putting much research and development into using cleaner
fuels such as ethanol and hydrogen as well as hydrogen fuel cells which
generate electrical power to propel the vehicle. Other clean sources of
power generation are also in development. Emissions from factories are
likewise regulated although enforcement of clean air legislation may
vary from one country to another.
Acid Rain
In addition to the health risks posed by just
breathing in the pollutants, another destructive phenomenon has been
observed: Acid Rain. Acid rain is rain or any other form of
precipitation that is unusually acidic. It has harmful effects on
plants, aquatic animals and buildings. The extra acidity in rain comes
from the reaction of primary air pollutants, primarily sulfur oxides and
nitrogen oxides, with water in the air to form strong acids (like
sulfuric and nitric acid). Acid rain has been shown to have adverse
impacts on forests, freshwaters and soils, killing off insect and
aquatic lifeforms as well as causing damage to buildings and having
possible impacts on human health. Though acid rain was discovered in
1852, it wasn't until the late 1960s that scientists began widely
observing and studying the phenomenon and heightened public awareness
came only in the 1990s.
Acid rain is mostly caused by
emissions of sulfur and nitrogen compounds which react in the atmosphere
to produce acids. The principal cause of acid rain is sulfur and
nitrogen compounds from human sources, such as electricity generation,
factories and motor vehicles. Coal power plants are one of the most
polluting. These gases can be carried hundreds of kilometers in the
atmosphere before they are converted to acids and deposited. In the
past, factories had short funnels to let out smoke, but this caused many
problems; thus, factories now have longer smoke funnels. However, this
causes pollutants to be carried farther, causing greater ecological
damage.
To reduce acid
rain, a number of international treaties on the long range transport of
atmospheric pollutants have been agreed e.g. the Sulphur Emissions
Reduction Protocol under the Convention on Long-Range Transboundary Air
Pollution. The US Clean Air Act Amendments of 1990 also addressed this
problem with new regulatory programs authorized for control of acid
deposition (acid rain).
On the technical side, many coal-burning power plants such as those in
the US use flue gas desulfurization(FGD) to remove sulphur-containing
gases from their stack gases. An example of FGD is the wet scrubber
which is commonly used in the U.S. and many other countries. A wet
scrubber is basically a reaction tower equipped with a fan that extracts
hot smoke stack gases from a power plant into the tower. Lime or
limestone in slurry form is also injected into the tower to mix with the
stack gases and combine with the sulphur dioxide present. The calcium
carbonate of the limestone produces pH-neutral calcium sulfate that is
physically removed from the scrubber. That is, the scrubber turns sulfur
pollution into industrial sulfates.
Automobile emissions control reduces emissions of nitrogen
oxides from motor vehicles.
Ozone Depletion
Ozone (O3) depletion describes two distinct, but related observations: a
slow, steady decline of about 4 percent per decade in the total amount
of ozone in the Earth's stratosphere since the late 1970s; and a much
larger, but seasonal, decrease in stratospheric ozone over Earth's polar
regions during the same period. The latter phenomenon is commonly
referred to as the “ozone hole”. Ozone depletion is caused by the
catalytic destruction of ozone by atomic chlorine and bromine. The main
source of these halogen atoms in the stratosphere is the
photodissociation of
chlorofluorocarbon (CFC) compounds, commonly called
freons, and
of
bromofluorocarbon
compounds known as
halons. These compounds are transported into the stratosphere
after being emitted at the surface. CFCs and other contributory
substances are commonly referred to as ozone-depleting substances (ODS).
Chlorofluorocarbons
(CFCs)
were invented in the 1920s. They were used in
air conditioning/cooling units, as
aerosol
spray propellants prior to the 1980s, and in the cleaning
processes of delicate electronic equipment. They also occur as
by-products of some chemical processes. No significant natural sources
have ever been identified for these compounds — their presence in the
atmosphere is due almost entirely to human manufacture.
Very large volcanic eruptions can inject hydrogen chloride (HCl)
directly into the stratosphere, but direct measurements have
shown that their contribution is small compared to that of
chlorine from CFCs. A similar erroneous assertion is that
soluble halogen compounds from the volcanic plume of
Mount Erebus on Ross Island, Antarctica was a major
contributor to the Antarctic ozone hole.
The Antarctic ozone hole is an area of the Antarctic stratosphere in
which the recent ozone levels have dropped to as low as 33% of their
pre-1975 values. The ozone hole occurs during the Antarctic spring, from
September to early December, as strong westerly winds start to circulate
around the continent and create an atmospheric container. Within this
"polar vortex", over 50% of the lower stratospheric ozone is destroyed
during the Antarctic spring.
As explained above, the overall cause of ozone depletion is the presence
of chlorine-containing source gases (primarily CFCs and related
halocarbons). In the presence of UV light, these gases dissociate,
releasing chlorine atoms, which then go on to catalyze ozone
destruction. The Cl-catalyzed ozone depletion can take place in the gas
phase, but it is greatly enhanced in the presence of
polar stratospheric
clouds (PSCs).
These polar stratospheric clouds form
during winter, in the extreme cold. Polar winters are dark, consisting
of 3 months without solar radiation (sunlight). Not only lack of
sunlight contributes to a decrease in temperature but also the “polar
vortex” traps and chills air. Temperatures hover around or below -80 °C.
These low temperatures form cloud particles and are composed of either
nitric acid or ice. Both types provide surfaces for chemical
reactions that lead to ozone destruction. The role of sunlight in ozone
depletion is the reason why the Antarctic ozone depletion is greatest
during spring. During winter, even though PSCs are at their most
abundant, there is no light over the pole to drive the chemical
reactions. During the spring, however, the sun comes out, providing
energy to drive photochemical reactions, and melt the polar
stratospheric clouds, releasing the trapped compounds.
Most of the ozone that is destroyed is in
the lower stratosphere, in contrast to the much smaller ozone depletion
through homogeneous gas phase reactions, which occurs primarily in the
upper stratosphere. Warming temperatures near the end of spring break up
the vortex around mid-December. As warm, ozone-rich air flows in from
lower latitudes, the PSCs are destroyed, the ozone depletion process
shuts down, and the ozone hole heals although not completely due to the
increased levels of ODS over the years resulting in the hole gradually
becoming larger as time passes.
Since the ozone layer prevents most harmful UVB wavelengths (270–315 nm)
of
ultraviolet
(UV) light
from passing through the
Earth's atmosphere, observed and projected decreases in ozone
have generated worldwide concern. Biological consequences such as
increases in skin
cancer, damage to plants, and reduction of
plankton
populations in the ocean's
photic zone may result from the increased UV exposure due
to ozone depletion.
After a 1976 report by the
U.S.
National Academy of Sciences concluded that credible scientific
evidence supported the ozone depletion hypothesis, few countries,
including the United States, Canada, Sweden, and Norway, moved to
eliminate the use of CFCs in aerosol spray cans. In 1985, 20 nations,
including most of the major CFC producers, signed the Vienna Convention
which established a framework for negotiating international regulations
on ozone-depleting substances. That same year, the discovery of the
Antarctic ozone hole was announced, causing a revival in public
attention to the issue. In 1987, representatives from 43 nations signed
the Montreal
Protocol. At Montreal, the participants agreed to freeze
production of CFCs at 1986 levels and to reduce production by 50% by
1999. After series of scientific expeditions to the Antarctic produced
convincing evidence that the ozone hole was indeed caused by chlorine
and bromine from manmade halogens, the Montreal Protocol was
strengthened at a 1990 meeting in London. The participants agreed to
phase out CFCs and halons entirely (aside from a very small amount
marked for certain "essential" uses, such as
asthma inhalers
) by 2000. At a 1992 meeting in Copenhagen, the phase out
date was moved up to 1996. Also, the US Clean Air Act Amendments of 1990
included provisions regarding stratospheric ozone protection.
Since the adoption and strengthening of
the Montreal Protocol has led to reductions in the emissions of CFCs,
atmospheric concentrations of the most significant compounds have been
declining. Gradually, the ozone layer is regenerating as new quantities
of ozone are formed in the atmosphere, but it will take years due to the
presence of the ODS which will still be floating in the atmosphere for
some time to come. It is expected complete recovery of the Antarctic
ozone layer will not occur until the year 2050 or later. Work has
suggested that a detectable (and statistically significant) recovery
will not occur until around 2024, with ozone levels recovering to 1980
levels by around 2068.
Although they are often interlinked in the
mass media,
the connection between global warming and ozone
depletion is not strong. There are some common grounds, for instance,
the same carbon dioxide (CO2) radiative forcing* that produces
near-surface global warming is expected to cool the
stratosphere. This cooling (cooler stratospheric temperatures,
more stratospheric clouds, more active chlorine), in turn, is expected
to produce a relative increase in
ozone
depletion and the frequency of ozone holes.
*In climate
science, radiative forcing is loosely defined as the change in net
irradiance at
the tropopause,
a boundary region in the
atmosphere between the
troposphere and the
stratosphere. Here, the air ceases to cool at -50°C
(-58°F),
and the air becomes almost completely dry. "Net irradiance" is the
difference between the incoming radiation energy and the outgoing
radiation energy in a given climate system.
Global
Climate Change
Besides the health dangers, acid rain and ozone depletion, some
scientists proposed that the accumulation of pollutants in the earth’s
atmosphere would have other more dire, far-reaching consequences. Here
are their scenarios:
 The
greenhouse effect is the process by which absorption and
emission of infrared radiation by atmospheric gases warm a
planet's lower atmosphere and surface. The detailed causes of
the recent warming remain an active field of research, but the
scientific consensus is that the increase in atmospheric
greenhouse gases such as carbon dioxide due to human activity
caused most of the warming observed since the start of the
industrial era.
An
increase in global temperatures may in turn cause
glacial retreat,
Arctic
shrinkage, and worldwide
sea level rise. A sea level rise of 110 to 770 millimeters (0.36
to 2.5 ft) between 1990 and 2100 is anticipated. Changes in the amount
and pattern of
precipitation may result in
flooding and
drought. There may also be changes in the frequency and intensity
of
extreme
weather events. Other effects may include changes in agricultural
yields, reduced summer
streamflows, species
extinctions, and increases in the range of
disease vectors
.
 In
an attempt to avert climate change, nations ratified the Kyoto Protocol.
The Kyoto Protocol is a
protocol
to the international
Framework Convention on Climate Change with the objective of
reducing
Greenhouse gases
that cause climate
change. It was agreed on
December 11,1997
at the
3rd Conference of the Parties to the treaty when they met in
Kyoto, and
took effect on
February 16,
2005. As of November 2007,
174 parties
have ratified the protocol. Of these, 36 developed
countries (plus the
European Union
as a party in its own right) are required to reduce greenhouse gas
emissions to the levels specified for each of them in the treaty.
But
whether any of the climate change scenarios are correct or even if they
are wholly wrong, the MCV Foundation through the DCV Program, still
believes in the good stewardship of the earth and part of this belief is
to maintain a clean and healthy environment for our generation and those
to follow.
Please
visit our page
DCV Poverty Alleviation Program and
join us, together, we can make the world a better
place.
Back to Top of Page
Home | About Us |
Poverty and Crime | Environmental Crisis |DCV
Poverty Alleviation Program
Nature's Guardians |New
Income Opportunities | FAQ |News
and Updates | Join Us |
Contact Us |Downloads
Copyright
© DCV Program |
The
Global Cooling Scenario:
In the 1970s, there was increasing awareness that estimates of
global temperatures showed cooling since 1945. The general public had
little awareness of carbon dioxide's
effects on climate. By the time the idea of
global cooling reached the public press in the mid-1970s, the
temperature trend had stopped going down, and there was concern in the
climatological community about