4. GLOBAL WARMING
Global warming, the phenomenon of increasing average air temperatures near the
surfaces Earth over the past 1-2 centuries. Climate scientist have since the mid-20th
century gathered detailed observations of various weather phenomena (such as
temperatures, precipitation and storms) and of related influences on climate (such as
the ocean currents and the atmosphere’s chemical composition). These data indicate
the Earth’s climate has changed over almost every conceivable timescale since the
beginning of geologic time and that the influence of human activities since the atleast
the beginning of the industrial revolution has been deeply woven into the very fabric of
climate changes.
Of all these gases, carbon dioxide is the most important, both for its role in the
greenhouse effect and for its role in the human economy. It has been estimated that,
at the beginning of the industrial age in the mid-18th century, carbon dioxide
concentrations in the atmosphere were roughly 280 parts per million (ppm). By the
middle of 2018 they had risen to 406 ppm, and, if fossil fuels continue to be burned at
current rates, they are projected to reach 550 ppm by the mid-21st century—
essentially, a doubling of carbon dioxide concentrations in 300 years.
5. FACTS OF GLOBAL
WARMING.
1) Australia’s fires are
seriously unprecedented.
2) Extreme weather
conditions have turned
something familiar into
something abnormal.
3) Scientists estimate that
Australia's fires have already
killed roughly a billion
animals, and some species
may not be able to recover.
4) Climate change will make
fire-prone conditions more
common in Australia.
6. CAUSES AND EFFECTS
•THE GREEN HOUSE EFFECT
Glaciers are melting, sea levels are raising, cloud forests are dying, and
wild life is scrambling to keep pace. It has become clear that humans have caused
most of the past century’s warming by releasing heat-trapping gases as we power our
modern lives. Called Greenhouse gases, their levels are higher now then at anytime in
the last 800000 years.
We often call the result the global warming, but it is causing a set of changes to the
earth’s climate, or long-term weather patterns, that varies from place to place. While
many people think of global warming and climate change has synonyms, scientists use
“climate change” when describing the complex shifts now effecting our planets
weather and climate systems-in part because in some areas actually get cooler in the
short term.
Climate changes encompasses not only raising average temperatures but also extreme
weather events, shifting wild life populations and habitats, rising seas, and a range of
other impacts. All of those changes are emerging as humans continue to add heat-
trapping green house gases to the atmosphere, changing the rhythms of climate that
all living things have come to rely on.
7. • RATIDATIVE FORCE
In light of the discussion above of the greenhouse effect, it is
apparent that the temperature of Earth’s surface and lower atmosphere may be
modified in three ways:
(1) through a net increase in the solar radiation entering at the top of Earth’s
atmosphere,
(2) through a change in the fraction of the radiation reaching the surface, and
(3) through a change in the concentration of greenhouse gases in the atmosphere. In
each case the changes can be thought of in terms of “radiative forcing.” As
defined by the IPCC, radiative forcing is a measure of the influence a given
climatic factor has on the amount of downward-directed radiant energy impinging
upon Earth’s surface. Climatic factors are divided between those caused
primarily by human activity (such as greenhouse effect emissions
and aersol emissions) and those caused by natural forces (such as solar
irradiance); then, for each factor, so-called forcing values are calculated for the
time period between 1750 and the present day. “Positive forcing” is exerted by
climatic factors that contribute to the warming of Earth’s surface, whereas
“negative forcing” is exerted by factors that cool Earth’s surface.
8. PREVENTIONS
1. Speak up!
What’s the single biggest way you can make an impact on global climate change?
“Talk to your friends and family, and make sure your representatives are making good
decisions,” Haq says. By voicing your concerns—via social media or, better
yet, directly to your elected officials —you send a message that you care about the
warming world. Encourage Congress to enact new laws that limit carbon emissions and
require polluters to pay for the emissions they produce. “The main reason elected
officials do anything difficult is because their constituents make them,” Haq says. You
can help protect public lands, stop offshore drilling, and more here.
2. Power your home with renewable energy.
Choose a utility company that generates at least half its power from wind or solar and
has been certified by Green-e effect an organization that vets renewable energy
options. If that isn’t possible for you, take a look at your electric bill; many utilities
now list other ways to support renewable sources on their monthly statements and
websites.
9. 3. Weatherize, weatherize, weatherize.
“Building heating and cooling are among the biggest uses of energy,” Haq says. Indeed,
heating and air-conditioning account for almost half of home energy use. You can make
your space more energy efficient by sealing drafts and ensuring it’s adequately
insulated. You can also claim federal tax credits for many energy-efficiency home
improvements.
4. Invest in energy-efficient appliances.
Since they were first implemented nationally in 1987, efficiency standards for dozens of
appliances and products have kept 2.3 billion tons of carbon dioxide out of the air.
That’s about the same amount as the annual carbon pollution coughed up by nearly 440
million cars. “Energy efficiency is the lowest-cost way to reduce emissions,” Haq says.
When shopping for refrigerators, washing machines, and other appliances, look for
the Energy Star label. It will tell you which are the most efficient.
5. Reduce water waste.
Saving water reduces carbon pollution, too. That's because it takes a lot of energy to
pump, heat, and treat your water. So take shorter showers, turn off the tap while
brushing your teeth, and switch to Water Sense-labeled fixtures and appliances. The
EPA estimates that if just one out of every 100 American homes were retrofitted with
water-efficient fixtures, about 100 million kilowatt-hours of electricity per year would be
saved—avoiding 80,000 tons of global warming pollution.
11. IMPORTANCE OF FOREST
Importance of forests :
1. Forests provide the wildlife shelter and a living.
2. Forests bear many flowers, fruits and roots which are suitable for human consumption.
3. Forests hold both the top and underground soil firmly and prevent soil erosion.
4. Wood from the forests is a great requirement in the production of furniture and in the
building of wooden houses.
5. Forests covering a large area promote perfect seasonal rains through their vast
amounts of transpiration.
6. Forests help in large scale exchange of gases and thence, demote the levels of air
pollution.
7.Many useful drugs and alkaloids are extracted from the forests.
8.Forests promote biodiversity to a great extent.
9.Forests enhance the rate of decomposition, formation of soil and hence maintain the
ecological services.
10. Either directly or indirectly, forests bless a large crowd with employment.
12. PREVENTION OF FORESTS
1. Regulated and Planned Cutting of Trees:
One of the main reasons of deforestation is commercial felling of trees. According
to an estimate, about 1,600 million cubic metres of wood have been used for various
purposes in the world. Although trees are considered as perennial resource, when
exploited on a very large scale, their revival cannot be possible.
Therefore, cutting should be regulated by adopting
methods like:
(i) Clear cutting,
(ii) Selective cutting, and
(iii) Shelter wood cutting.
The clear cutting method is useful for those areas where the same types of trees
are available over a large area. In that case, trees of same age group can be cut
down in a selected area and then marked for replantation. In selective cutting only
mature trees are selected for cutting. This process is to be followed in rotation.
Sheker wood cutting is where first of all useless trees are cut down followed by
medium and best quality timber trees.
13. 3. Reforestation and Aforestation:
The sustained yield concept dictates that whenever timber is removed, either by block
cutting or by selective cutting, the denuded area must be reforested. This may be done
by natural or artificial methods. Similarly, any forested land, which has been destroyed
by fire or mining activities, should be reforested. In rugged terrain aerial seeding is the
method of choice.
4. Check over Forest Clearance for Agricultural and Habitation
Purposes:
Most of the present-day agricultural land was once forested and then cleared for the
use of agriculture. But now it has reached the stage where further clearance will be
dangerous for the entire ecosystem. There are tribal's in some parts of Asia, Africa and
South America, where shifting cultivation is still a part of their system of land
procurement.
5. Protection of Forests:
The existing forests should be protected. Apart from commercial cutting, unorganized
grazing is also one of the reasons. There are several forest diseases resulting from
parasitic fungi, rusts, mistletoes, viruses and nematodes which cause the destruction of
trees. The forests should be protected either by use of chemical spray, antibiotics or
by development of disease resistant strains of trees.
14. 6. Proper Utilization of Forest and Forests Products:
Generally, trees are cut for logs and the rest, including stump, limbs, branches and
foliage, etc., is left out as worthless debris. Further waste occurs at the saw mills.
There is thus need to utilize this waste material. Today, several uses have been
developed and products like waterproof glues, boar r etc., can be obtained.
Both national and provincial governments can take some steps
in this direction, such as:
(i) Pass acts for the conservation of forests,
(ii) Survey of the forest resources,
(iii) Categorization of forest areas and proper delimitation of reserved forest areas,
(iv) Find out the areas where reforestation can be done,
(v) Regulate the commercial use of forest products,
(vi) Protect forest from fire, mining and other natural calamities,
(vii) Develop national parks,
(viii) Encourage forests developmental activities like social forestry, agro-forestry,
etc., and
(ix) Prepare master plans, both for long-term and short-term period, etc.
