WATER CRISIS & CLIMATE CHANGE - PowerPoint PPT Presentation

View by Category
About This Presentation
Title:

WATER CRISIS & CLIMATE CHANGE

Description:

ABOUT WATER CRISIS & CLIMATE CHANGE – PowerPoint PPT presentation

Number of Views:208

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: WATER CRISIS & CLIMATE CHANGE


1
WATER CRISIS CLIMATE CHANGE

2
(No Transcript)
3
(No Transcript)
4
DROUGHT
5
WATER WATER EVERYWHERE NOR A DROP
TO DRINK
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
WATER SCARCITY
Water scarcity is the lack of sufficient
available water resources to meet the demands
of water usage within a region. It already
affects every continent and around 2.8 billion
people around the world at least one month out of
every year. More than 1.2 billion people lack
access to clean drinking water.
11
Water scarcity involves water stress, water
shortage or deficits, and water crisis. While the
concept of water stress is relatively new, it is
the difficulty of obtaining sources of fresh
water for use during a period of time and may
result in further depletion and deterioration of
available water resources.2 Water shortages may
be caused by climate change, such as altered
weather patterns including droughts or floods,
increased pollution, and increased human demand
and overuse of water.3 A water crisis is a
situation where the available potable, unpolluted
water within a region is less than that region's
demand.4 Water scarcity is being driven by two
converging phenomena growing freshwater use and
depletion of usable freshwater resources
12
Water scarcity can be a result of two
mechanisms physical (absolute) water
scarcity and economic water scarcity, where
physical water scarcity is a result of inadequate
natural water resources to supply a region's
demand, and economic water scarcity is a result
of poor management of the sufficient available
water resources. According to the United Nations
Development Programme, the latter is found more
often to be the cause of countries or regions
experiencing water scarcity, as most countries or
regions have enough water to meet household,
industrial, agricultural, and environmental
needs, but lack the means to provide it in an
accessible manner.6 The reduction of water
scarcity is a goal of many countries and
governments. The UN recognizes the importance of
reducing the number of people without sustainable
access to clean water andsanitation.
The Millennium Development Goals within
the United Nations Millennium Declaration state
that by 2015 they resolve to "halve the
proportion of people who are unable to reach or
to afford safe drinking water."7
13
Water crisis
When there is not enough potable water for a
given population, the threat of a water crisis is
realized.4 The United Nations and other world
organizations consider a variety of regions to
have water crises of global concern.1213 Other
organizations, such as the Food and Agriculture
Organization, argue that there are no water
crises in such places, but steps must still be
taken to avoid one.14
14
Causes of water crisis
  • There are several principal manifestations of the
    water crisis.
  • Inadequate access to safe drinking water for
    about 884 million people15
  • Inadequate access to sanitation for 2.5 billion
    people16 which often leads to water pollution
  • Groundwater over drafting (excessive use) leading
    to diminished agricultural yields17
  • Overuse and pollution of water resources
    harming biodiversity
  • Regional conflicts over scarce water resources
    sometimes resulting in warfare

15
CLIMATE CHANGE
Climate change is a change in the statistical
distribution of weather patterns when that change
lasts for an extended period of time (i.e.,
decades to millions of years). Climate change may
refer to a change in average weather conditions,
or in the time variation of weather around
longer-term average conditions (i.e., more or
fewer extreme weather events). Climate change is
caused by factors such as biotic processes,
variations in solar radiation received by Earth,
plate tectonics, and volcanic eruptions. Certain
human activities have also been identified as
significant causes of recent climate change,
often referred to as "global warming".
16
CAUSES
On the broadest scale, the rate at which energy
is received from the sun and the rate at which it
is lost to space determine the equilibrium
temperature and climate of Earth. This energy is
distributed around the globe by winds, ocean
currents, and other mechanisms to affect the
climates of different regions. Factors that can
shape climate are called climate forcing or
"forcing mechanisms".6 These include processes
such as variations in solar radiation, variations
in the Earth's orbit, variations in the albedo or
reflectivity of the continents and oceans,
mountain-building and continental drift and
changes in greenhouse gas concentrations. There
are a variety of climate change feedbacks that
can either amplify or diminish the initial
forcing. Some parts of the climate system, such
as the oceans and ice caps, respond more slowly
in reaction to climate forcing, while others
respond more quickly. There are also key
threshold factors which when exceeded can produce
rapid change.
17
Forcing mechanisms can be either "internal" or
"external". Internal forcing mechanisms are
natural processes within the climate system
itself (e.g., the circulation). External forcing
mechanisms can be either natural (e.g., changes
in solar output) or anthropogenic (e.g.,
increased emissions of greenhouse gases). Whether
the initial forcing mechanism is internal or
external, the response of the climate system
might be fast (e.g., a sudden cooling due to
airborne volcanic ash reflecting sunlight), slow
(e.g. thermal expansion of warming ocean water),
or a combination (e.g., sudden loss of albedo in
the arctic ocean as sea ice melts, followed by
more gradual thermal expansion of the water).
Therefore, the climate system can respond
abruptly, but the full response to forcing
mechanisms might not be fully developed for
centuries or even longer. Internal forcing
mechanisms Scientists generally define the five
components of earth's climate system to include
atmosphere, hydrosphere, cry sphere, lithosphere
(restricted to the surface soils, rocks, and
sediments), and biosphere.7 Natural changes in
the climate system ("internal ") result in
internal "climate variability".8 Examples
include the type and distribution of species, and
changes in ocean currents.
18
CLIMATE CHANGE
19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
22
Ocean variability Main article Thermohaline
circulation See also Climate inertia Pacific
Decadal Oscillation 1925 to 2010 The ocean is a
fundamental part of the climate system, some
changes in it occurring at longer timescales than
in the atmosphere, massing hundreds of times more
and having very high thermal inertia (such as the
ocean depths still lagging today in temperature
adjustment from the Little Ice Age).clarification
needed9 Short-term fluctuations (years to a
few decades) such as the El Niño-Southern
Oscillation, the Pacific decadal oscillation, the
North Atlantic oscillation, and the Arctic
oscillation, represent climate variability rather
than climate change. On longer time-scales,
alterations to ocean processes such as
thermohaline circulation play a key role in
redistributing heat by carrying out a very slow
and extremely deep movement of water and the
long-term redistribution of heat in the world's
oceans. A schematic of modern thermohaline
circulation. Tens of millions of years ago,
continental-plate movement formed a land-free gap
around Antarctica, allowing the formation of the
ACC, which keeps warm waters away from Antarctica.
23
Life Life affects climate through its role in the
carbon and water cycles and through such
mechanisms as albedo, evapotranspiration, cloud
formation, and weathering.101112 Examples
of how life may have affected past climate
include glaciations 2.3 billion years ago
triggered by the evolution of oxygenic
photosynthesis1314 glaciations 300 million
years ago ushered in by long-term burial of
decomposition-resistant detritus of vascular
land-plants (forming coal)1516 termination of
the Paleocene-Eocene Thermal Maximum 55 million
years ago by flourishing marine
phytoplankton1718 reversal of global warming
49 million years ago by 800,000 years of arctic
azoles blooms1920 global cooling over the
past 40 million years driven by the expansion of
grass-grazer ecosystems2122
24
Solar output Main article Solar
variation Variations in solar activity during
the last several centuries based on observations
of sunspots and beryllium isotopes. The period of
extraordinarily few sunspots in the late 17th
century was the Maunder minimum. The Sun is the
predominant source of energy input to the Earth.
Both long- and short-term variations in solar
intensity are known to affect global
climate. 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
Hadean2829 and Arching3028 eons, leading
to what is known as the faint young Sun
paradox.31 Hypothesized solutions to this
paradox include a vastly different atmosphere,
with much higher concentrations of greenhouse
gases than currently exist.32 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 dwarf will have large
effects on climate, with the red giant phase
possibly ending any life on Earth that survives
until that time. Solar output also varies on
shorter time scales, including the 11-year solar
cycle33 and longer-term modulations.34 Solar
intensity variations possibly as a result of the
Wolf, Sparer and Maunder Minimum are considered
to have been influential in triggering the Little
Ice Age,35 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. that was marked by relative
cooling and greater glacier extent than the
centuries before and afterward.3637 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
radioactive forcing, etc.).3839
25
Human influences Increase in atmospheric CO2
levels Main article Global warming In the
context of climate variation, anthropogenic
factors are human activities which affect the
climate. The scientific consensus on climate
change is "that climate is changing and that
these changes are in large part caused by human
activities,"59 and it "is largely
irreversible."60 Science has made enormous
inroads in understanding climate change and its
causes, and is beginning to help develop a strong
understanding of current and potential impacts
that will affect people today and in coming
decades. This understanding is crucial because it
allows decision makers to place climate change in
the context of other large challenges facing the
nation and the world. There are still some
uncertainties, and there always will be in
understanding a complex system like Earths
climate. Nevertheless, there is a strong,
credible body of evidence, based on multiple
lines of research, documenting that climate is
changing and that these changes are in large part
caused by human activities. While much remains to
be learned, the core phenomenon, scientific
questions, and hypotheses have been examined
thoroughly and have stood firm in the face of
serious scientific debate and careful evaluation
of alternative explanations. United States
National Research Council, Advancing the Science
of Climate Change
26
Vegetation A change in the type, distribution and
coverage of vegetation may occur given a change
in the climate. Some changes in climate may
result in increased precipitation and warmth,
resulting in improved plant growth and the
subsequent sequestration of airborne CO2. A
gradual increase in warmth in a region will lead
to earlier flowering and fruiting times, driving
a change in the timing of life cycles of
dependent organisms. Conversely, cold will cause
plant bio-cycles to lag.69 Larger, faster or
more radical changes, however, may result in
vegetation stress, rapid plant loss and
desertification in certain circumstances.7071
An example of this occurred during the
Carboniferous Rainforest Collapse (CRC), an
extinction event 300 million years ago. At this
time vast rainforests covered the equatorial
region of Europe and America. Climate change
devastated these tropical rainforests, abruptly
fragmenting the habitat into isolated 'islands'
and causing the extinction of many plant and
animal species.70
27
SAPPHIRE
  1. AMJATH P.M(LEADER)
  2. BASIL AHMED(ASST LEADER)
  3. MOHAMMED NIHAD A.N
  4. AJITH.R.NAIR
  5. ASEEM IRFAN
  6. HARSHAD AMAN
  7. ANAS ASHRAF(CREATED BY)
  8. ABISHEK V.S

28
THE END
About PowerShow.com