2. CAUSES OF ENVIRONMENTAL
CHANGES:
There are many causes of environmental changes on Earth. Natural events cause a change in the climate. For example,
large volcanic eruptions release tiny particles into the atmosphere that block sunlight, resulting in surface cooling that
lasts for a few years. Variations in ocean currents such as El Niño can also change the distribution of heat and
precipitation. Over longer periods, tens to hundreds of thousands of years, natural changes in the geographical
distribution of energy from the Sun and in the number of greenhouse gases and dust in the atmosphere have caused the
climate to shift from ice age to a relatively warmer period. On a large timescale, the presence of life on Earth has changed
the environment of the planet radically, transforming a predominantly reducing atmosphere made up of methane and
ammonia to today's oxygen-rich gaseous envelope.
3. GREEN HOUSE PHENOMENON
In addition to desertification, changes caused by human activities
include recent increases in the atmospheric concentrations of both
greenhouse gases and sulfate particles ("aerosols"). Greenhouse
gases such as carbon dioxide cover the atmosphere's "infrared
window," and trap heat. Data from satellites can trace changes in the
globally averaged surface temperature of Earth and can be used to
predict temperature changes in the future. According to some
models, if current trends continue, the amount of carbon dioxide in
the atmosphere will double during the twenty-first century, and the
average rate of warming of Earth's surface over the next hundred
years will probably be greater than it was at any time in the last
10,000 years. The current best estimate of the expected rise of
globally averaged surface temperature relative to 1990 is 1°C to 3.5°C
by the year 2100, with continued increases thereafter.
4. OZONE DEPLETION
Around 1985 scientists taking ozone (O3) measurements in the
Antarctic detected an alarming decrease in stratospheric ozone
concentrations over the South Pole. This decline in atmospheric
ozone was verified by instruments aboard the National Aeronautics
and Space Administration's (NASA)'s Nimbus-7 satellite. Under usual
circumstances, ultraviolet radiation helps create and destroy ozone
molecules. It is strong enough to break both ozone and oxygen
molecules into individual oxygen atoms. This destruction of
molecules allows the free oxygen atoms to bond with other oxygen
molecules and form more ozone. However, chlorofluorocarbon (CFC)
compounds such as the freon used in refrigeration systems upset this
balance and destroy ozone (CFCs also are greenhouse gases). The
depletion of ozone caused by CFCs results in increased ultraviolet
radiation at Earth's surface that could be highly damaging to sensitive
Arctic life forms. Ozone losses over the Arctic could also reduce
5. STEPS AND INITIATIVES TAKEN BY
GOVERNMENT TO CONTROL AIR
POLLUTION AND OZONE DEPLETION
1: Eliminate production and release of known ozone-depleting
chemicals (such as CFCs and HCFCs) were remotely possible.
2: The government of Delhi started the “red light on gaddi off
campaign”.
3 : Environment Minister Gopal Rai appealed to the citizens to turn
their cars off at red lights to help reduce air pollution.
4: govt has started green India clean India movement.
6. COP 26
What is cop 26?
It is the 26th iteration of the Conference of the Parties to the UN
Framework Convention on Climate Change (UNFCCC). This annual
meeting brings together the 197 members of the convention to take
concerted action on climate change. What is the talk or discussion in
this meeting? At the meeting, country representatives discuss issues
such as climate change mitigation (the reduction of greenhouse gas
emissions that cause the planet to warm), adaptation to irreversible
environmental impacts caused by climate change, and financing to
support developing countries in their efforts to move away from fossil
fuels and become more resilient to the impacts of climate change.
