Environment Past & Present

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Three to four billion years ago

Solar Energy effects on earth:

Present Environment Issues:

Three to four billion years ago the sun emitted only 70% as much power as it does today. If the atmospheric

composition had been the same as today, liquid water should not have

existed on Earth. However, there is evidence for the presence of water on

the early Earth, in the Hadean and Archeaneons, leading to what is known

as the faint young Sun paradox. Hypothesized solutions to this paradox

include a vastly different atmosphere, with much higher concentrations

of greenhouse gases than currently exist. Over the following

approximately 4 billion years, the energy output of the sun increased and

atmospheric composition changed. The Great Oxygenation Event -

oxygenation of the atmosphere- around 2.4 billion years ago was the

most notable alteration. Over the next five billion years the sun's ultimate

death as it becomes a red giant and then a white dwarfwill have large

effects on climate, with the red giant phase possibly ending any life onEarth that survives until that time.

Solar output also varies on shorter time scales, including the 11-year solar cycle and longer-term

modulations. Solar intensity variations are considered to have been influential in triggering the Little Ice Age, and

some of the warming observed from 1900 to 1950. The cyclical nature of the sun's energy output is not yet fully

understood; it differs from the very slow change that is happening within the sun as it ages and evolves. Research

indicates that solar variability has had effects including the Maunder Minimum from 1645 to 1715 A.D.., part of the

Little Ice Age from 1550 to 1850 A.D. which was marked by relative cooling and greater glacier extent than the

centuries before and afterward. Some studies point toward solar radiation increases from cyclical sunspot activity

affecting global warming, and climate may be influenced by the sum of all effects (solar variation, anthropogenic

radiative forgings, etc.).

Environmental issues are a global concern in the current scenario. This has

been prompted by the realization that human activities have already inflicted

much damage on the surrounding environment and it is high time that we

take stock of our activities to take care of the same. The sun is the

predominant source for energy input to the Earth. Both long- and short-

term variations in solar intensity are known to affect global climate.

There are too many environmental issues that require attention.These can be grouped under three broad categories. These global

warming, waste management and obviously the overuse of the natural

resources. Environmental pollution is not meant only air pollution but also

water, soil, noise and light pollution.

Scientists generally define the five components of earth's climate system

to include Atmosphere, hydrosphere, cry sphere, lithosphere (restricted to the

ENVIRONMENT PAST & PRESENTNVIRONMENT PAST & PRESENTNVIRONMENT PAST & PRESENTBhupinder SinghBhabour Sahib, Punjab


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surface soils, rocks, and sediments), and biosphere. Though the categories are different, the activities of one

category have consequently resulted in the impact mentioned in the other category. For example, the Earth once

had plentiful resources in the form of rich reserves of fossil fuels. But the overuse of these fossil fuels have not only

depleted their reserves but also led to excessive emission of greenhouse gases that have caused much harm to the

ozone layer. It is responsible for global warming that has resulted in climate changes all across the world that has had

an impact on life on Earth. We can discuss few issues as under:

This is one of the greatest problems that now

world is facing Air Pollution and causing grave

and irreparable damage to the ozone layer. Air

pollution is cause by the injurious smoke emitted

by cars, buses, trucks, trains, and factories,

namely sulpher dioxide, carbon monoxide and

nitrogen oxides. Evidence of increasing air

pollution is seen in lung cancer, asthma, allergies,

and various breathing problems along with

severe and irreparable damage to flora and

fauna. Chlorofluorocarbons (CFC), released fromrefrigerators, air-conditioners, deodorants and

insect repellents cause severe damage to the

Earth's environment. This gas has slowly

damaged the atmosphere and depleted the

ozone layer leading to global warming.

Water pollution caused industrial waste

products released into lakes, rivers, and

other water bodies. Humans pollute

water with large scale disposal of

garbage, flowers, ashes and other

household waste. Domestic sewage also

refers to waste water that is discarded

from households. Also referred to as

sanitary sewage, such water contains a

wide variety of dissolved and suspended

impurities. In many rural areas one can

still find people bathing and cooking in

the same water, making it incredibly

filthy. Acid rain further adds to water

pollution in the water. In addition tothese, thermal pollution and the

depletion of dissolved oxygen aggravate

the already worsened condition of the

water bodies. Water pollution can also indirectly occur as an offshoot of soil pollution through surface runoff and

leaching to groundwater. Burning of fossil fuels the emitted ash particles usually contain toxic metals (such as As or

Pb). Burning will also add a series of oxides including carbon dioxide to air and respectively water bodies.

Air Pollution:

Water pollution:


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Noise pollution

Soil pollution

Noise pollution, soil pollution and light pollution too are the damaging the environment at an alarming rate. Noise

pollution include aircraft noise, noise of cars, buses, and trucks, vehicle horns, loudspeakers, and industry noise, as

well as high-intensity sonar effects which are extremely harmful for the environment. Maximum noise pollution

occurs due to one of modern science's best discoveries the motor vehicle, which is responsible for about ninety

percent of all unwanted noise worldwide.

Soil pollution, which can also

be called soil contamination, is

a result of acid rain, polluted

water, fertilizers etc., which

leads to bad crops. Soil

contamination occurs when

chemicals are released by spill

or underground storage tank

leakage which releases heavy

contaminants into the soil.

T h e s e m a y i n c l u d e

hydrocarbons, heavy metals,

MTBE, herbicides, pesticides

and chlorinated hydrocarbons.

c a r r y i n g f e r t i l i z e r s ,

pesticides/insecticides/herbici

des and other pollutants into

water bodies such as lakes,

rivers, ponds). The usual effect

of this type of pollution consists in algae growing in affected water bodies. This is a sign of increased nitrates and

phosphates in water that could be harmful for human health. mining activities involve crushing the rock that usuallycontains many trace metals and sulfides. The left material may easily generate sulfuric acid in the presence of

precipitation water. Please, read more at Mining Sites.

Light Pollution includes light trespass, over-illumination and astronomical interference.

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods

ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of

events around that average (e.g., more or fewer extreme weather events). Climate change may be limited to a

specific region or may occur across the whole Earth.

The most general definition ofclimate change is a change in the statistical properties of the climate system when

considered over long periods of time, regardless of cause. Accordingly, fluctuations over periods shorter than a few

decades, such asEl Nio, do not represent climate change.

The term sometimes is used to refer specifically to climate change caused by human activity, as opposed to changes

in climate that may have resulted as part of Earth's natural processes. In this sense, especially in the context of

environmental policy, the term climate change has become synonymous with anthropogenic global warming.

Within scientific journals, global warming refers to surface temperature increases while climate change includes

global warming and everything else that increasing greenhouse gas levels will affect.

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Environment Past & Present