Transcript Geog Project~Global Warming 3x lau yan yiu

4A
LAU SIN YIN
4B
CHOW HAU YI
4D
LAU YAN YU
SHUM KING SUN
Environmental problems are becoming more and
more serious in the world, and yet, humans are still
neglecting its significance. Or, maybe we can’t
blame humans if we don’t know much about what
is happening around us.
Today, we are going to explain the
most ignored but serious global
environmental problem – Global
warming.
Global warming refers to the increase in the
average temperature of the Earth and changes
in the amount and pattern of precipitation.
Global average near-surface atmospheric
temperature rose 0.6 ± 0.2 °C in the 20th
century. The prevailing scientific opinion on
climate change is that most of the warming
observed over the last 50 years is attributable
to human activities.
Why global warming has become a
major environmental issue all over the
world?
on a year to year,month to month,and day to day
scale,a change in air temperature of a few degrees
may not be very significant.
But an increase in global temperatures is expected
to cause other changes, including weather, sea level
and ecosystem,increased intensity of extreme
weather events,and changes in the amount and
pattern of precipitation. Other effects of global
warming include changes in agricultural yields,
glacier retreat, species extinctions and increases in
the ranges of disease vectors.This is why global
warming has become a major environmental issue all
over the world.
< 1880s to 2000s,
Global
Temperatures
changes
1000s to 2000s ,
>
Reconstructed temperature
change
All of us know the activity that’s increasing
the speed of Global Warming is called
greenhouse effect.
But DO YOU KNOW HOW IT’S WORK??
How does Greenhouse effect work?
The greenhouse
effect is the process
by which
absorption and
emission of
infrared radiation
by gases in the
atmosphere warm a
planet 's lower
atmosphere and
surface.
The Earth has cycled many years of warming
and cooling over the billions of years but it’s
increasing faster than ever and can’t be
explained with natural processes.
Clearly, humans are chief offender .
We are accelerating the natural climatological
cycles with our human-created emissions of
greenhouse gases .
What have human done?
Human activities: Effects:
Fossil fuel power
plant
Release CO2
Deforestation
25% of all CO2
release entering the
atmosphere
Release greenhouse
gases
Release methane
Buildings(require
lots of fuel)
rice paddies,
bovine flatulence
1.Rising sea levels
As the earth gets warmer , the snow and ice
cover will melt , meltwater would run into the
ocean .The thermal expansion of seawater will
lead to a rise in sea level.
2.Change in climate
-more frequent extreme climate events
-precipitation patterns
-climate regions
3.Change in world ecosystem
-desertification
-extinction of species
-bleaching of coral
1.Health risk
Climate change will alter the distribution pattern
of parasites , bacteria and carriers of infectious
diseases .Hotter summers will lead to more cases of
heat-related health problems.
2.Coastal flooding
Bring disaster to billions of people living in coastal
areas and low-lying countries.
3.Agriculture and food supply
A warmer climate would lead to a loss of soil
moisture because of a higher evaporation rate.
4.Freshwater supply
Higher evaporation rate may lead to shortage of
freshwater supply.
 A) Signing and ratifying Kyoto Protocol
 B) Adopting the Bail Roadmap
a) Engaging in a large-scale
afforestation
b) Reduce greenhouse gas emissions






-replacing fossil fuels with renewable power
resources
-use cleaner fuels
-improving energy efficiency
-improving transport systems
-recycling waste
-raising public awareness through education
c) Developing in a sustainable way
 control population growth
 farm in a sustainable way
 develop technologies that are friendly
 develop our cities in a way that the emission of
greenhouse gases can be kept as low as possible
At home:
 -Take shorter showers
 -change tungsten light bulbs to fluorescent bulbs
 -grow more plants
 -set the air conditioning temperature at 25℃or higher
 -Open windows to get fresh air instead of turning on the
air conditional
 -switch off electrical appliances rather than leave on
standby
Shopping
-bring your own bag
-run washing machine with full load
-buy recyclable products
-choose energy-efficient products
-reduce the amount of packaging
Transport and travel
 -use mass transit systems
 -take fewer flights
 -more cycling and walking
Others
 -take stairs instead of elevators
 -eat less meat
 -consume locally produced and seasonal food
 a) Different viewpoints of countries
 -it is unfair as less developed countries were not
required to take any responsibility to control their
emission
 -only the more developed countries control their
emission will not help ease the problem
 b) Their countries will be affected
 -Tight emission control sets in the Kyoto Protocol will
hinder the economy
 -meeting the emission target incurred extra costs