this topic is prepared from millers book titled "living in the environment".

1. Presented by: Faisal Sadiq
Roll No. 266
Class: BS 7th semester
Subject: Environmental Biology

2.  Whether: short-term changes in atmospheric variables
in a given area over a period of hours or days, such as
 Temperature
 Precipitation
 Wind
 Pressure
 Climate:
average weather conditions of the earth or of a
particular area over a long period of time
 ranging from decades and centuries to thousands of years.

3. The earth’s climate is affected by
solar energy
global air circulation
patterns
global ice cover
concentrations of the
different gases

5. For the past 1,000 years, the average temperature of
the atmosphere has remained fairly stable but began to
rise after industrial revolution
Climate change

6. •About 1% of the earth’s lower atmosphere is
composed of greenhouse gases,
water vapor (H2O)
carbon dioxide (CO2)
methane (CH4),
nitrous oxide (N2O)

8. since1906, the average global surface
temperature has risen by about 0.74 C°
Annual greenhouse gas emissions rose 70%.
, glaciers are melting
During the 20th century, the world’s average
sea level rose by 19 centimeters

11. CO2 Emissions
 It plays an important role in determining the
average temperature of the atmosphere.
 concentration of CO2 rose from 285 parts per
million (1850), to 389 ppm in 2010.
 450 ppm is an estimated threshold, or irreversible
tipping point, that could lead to an irreversible
climate change.
 Burning of fossils
 deforestation

12. Since the Industrial Revolution
Carbon dioxide rose from a level of 280
ppm to 389 ppm in 2010.
methane (CH4): ___________ 70%
o Agriculture
Nitrous oxide (N2O)_________20%
ouse of nitrogen fertilizers.
ohas 298 times the warming potential
than CO2.

13.  The world’s oceans absorb CO2 from the
atmosphere(25–30% )
 The ability of the oceans to absorb CO2 also
decreases when water temperatures increase.
 Increasing levels of CO2 in the ocean have
increased the acidity
 Acidity threatens
 corals
 phytoplankton
 ocean food webs

14.  The role played by clouds is quite uncertain.
 Warmer temperatures increase evaporation
of and create more clouds, which can cool or
warm the atmosphere
 thick cumulus clouds could decrease
temperature by reflecting more sunlight back
into space.
 thin, cirrus clouds could increase
temperature by preventing heat from
escaping into space.

16.  air pollution from human activities has slowed
the rate of atmospheric warming.
 Aerosols released by volcanic eruptions and
human activities such as sulfate particles tend
to reflect incoming sunlight and cool the lower
atmosphere.
 Also serve as a condensation nuclei that form
cooling clouds
 But since such pollution kills more than 800,000
people a year

17. Severe Drought
 when evaporation exceeds precipitation for a
prolonged period.
 southern Australia
 western United States
 wildfires increase
 Dessert expansion
 Water crises
 declining biodiversity

18.  Light-colored ice and snow help to cool the
earth by reflecting incoming solar energy
 glaciers store water as ice during cold wet
seasons and releasing it slowly to streams
during warmer dry seasons.

19.  The amount of carbon locked up as methane
(CH4) in permafrost soils is 50–60 times the
amount emitted as carbon dioxide from
burning fossil fuels each year
 If the permafrost melts, significant amounts
of CH4 and CO2 will be released

21.  Degradation of at least one-third of the world’s
coastal estuaries, wetlands, and coral reefs.
 Disruption of many of the world’s coastal
fisheries.
 Flooding of agricultural lowlands and deltas in
coastal areas where much of the world’s rice is
grown.
 Bangladesh.
 Saltwater contamination of coastal aquifers
 Submersion of low-lying islands

22.  atmospheric warming will increase the
incidence of extreme weather events.
 As a warmer atmosphere can hold more
moisture, some areas will experience severe
droughts and heat waves and other will face
other increased flooding from heavy and
prolonged snow or rainfall
 Threat to Biodiversity

23.  Farming, probably more than any other
human activity, depends on a stable climate.
Thus, farmers will face dramatic changes due
to shifting climates

24.  Prolonged heat waves will increase
numbers of deaths and illnesses,
 especially among older people, people in poor
health, and poor who cannot afford air
conditioning.
 A warmer, CO2-rich world will be a great
place for rapidly multiplying insects,
microbes, toxic molds, and fungi that
make us sick,

25. Reduce Greenhouse Gas Emissions
 reduce fossil fuel use, especially use of
coal is 80% of the solution
 Shift from nonrenewable carbon-based
fossil fuels to a mix of low-carbon
renewable energy resources.
 Stop cutting forests and plant trees which
remove CO2 from the atmosphere.
 Shift to more sustainable and climate-
friendly agriculture.

26. To manipulate certain natural conditions to
help counter an enhanced greenhouse
effect.
 scientists have suggested to inject sulfate
particles into the stratosphere.
 Some scientists reject the idea of launching
sulfates into the stratosphere as being too
risky because of our limited knowledge
about possible unknown effects.
Geo-engineering

27. Governments actions
 regulate carbon dioxide and methane as air
pollutants.
 phasing in carbon taxes on each unit of CO2
or CH4 emitted by fossil fuel use
 subsidies to businesses to encourage their
use of energy- efficiency technologies, low-
carbon renewable energy sources, and more
sustainable agriculture.