ppt on climate change useful for teaching purpose

1. GLOBAL CLIMATE : CAUSES AND CONESEQUENCES ON
ENVIRONMENT AND HEALTH
Dr. Akhilesh Kumar Tripathi
(MD)

2. 1. Background
2. Definition
3. The Climate system
4. Intergovernmental Panel on Climate Change (IPCC)
5. Challenges for scientists
6. Impacts on health of climate extreams
7. Climate change & Infectious diseases
8. Ozone depletion: Montreal Protocol
9. Conclusions & Recommendations
OBJECTIVES

3. • “The world’s climate system is an integral part of this complex of life-supporting
processes, one of many large natural systems that are now coming under
pressure from the increasing weight of human numbers and economic activities”. (
by A.J.McMicheal )
• The primary challenge facing the world community is to achieve sufficient
reduction in greenhouse gas emissions so as to avoid dangerous interference in
the climate system.
INTRODUCTION

4. • The scale of environmental health problems has expanded from household
(indoor air pollution) to neighbourhood (domestic refuse) to community
(urban air pollution) to regional (acid rain) to global level (climate change).
“Human alteration of Earth is substantial and growing. Between one-
third and one half of the land surface has been transformed by human action; the
carbon dioxide concentration in the atmosphere has increased by nearly 30%
since the beginning of the Industrial Revolution; more atmospheric nitrogen is
fixed by humanity than by all natural terrestrial sources combined; more than half
of all accessible surface fresh water is put to use by humanity; and about one-
quarter of the bird species on Earth have been driven to extinction. By these and
other standards, it is clear that we live on a human-dominated planet.”
(by..Vitousek)

5. The US Global Change Research Program recently documented how the various effects of climate change on aquatic
ecosystem can interact and ripple through trophic levels in unpredictable ways. For Example...
Melting sea ice
in warm artic region
Impairing survival of and seal pups
walrus
with decrease
seal pups , sea
utters are the
food alternate
for killer whale
decrease sea utters lead to increase sea urchin,
which results in decrease space for sea kelp
sea kelp are primary
breeding ground for
various fish
fewer fish
declines walrus &
seal population
less food available for
YUPLIK ESKIMOS
who rely on these
specis sea utters feeds
on sea urchin

6. • Weather is the state of the atmosphere at a specific time in a specific place.
Ex:Temperature, cloudiness, humidity, precipitation etc.
• Climate is defined as long-term weather patterns that describe a region.
Ex : The New York metropolitan region’s climate is temperate, with rain
evenly distributed throughout the year.
• Climate change is defined as change in the state of the climate that can be
identified by changes in the mean and/or the variability of its properties, and
that persists for an extended period, typically decades or longer.
It refers to any change in climate over time, whether due to natural
variability or as a result of human activity.
DEFINITIONS

7. Greenhouse gases:
• Carbondioxide(CO2)
• fossil fuel combustion
• forest burning
• Methane(CH4)
• irrigated agriculture
• animal husbandry
• oil extraction
• Nitrous Oxide(N2O)
• Chlorofluorocarbons(CFCs)
• Water Vapour
Intergovernmental
Panel on Climate
Change (IPCC) :
“There is new and
stronger evidence
that most of the
warming observed
over the last 50
years is attributable
to human
activities”

8. • Earth’s climate is determined by complex interactions among the Sun,
oceans, atmosphere, land surface.
• The Sun is the principal driving force for weather and climate. The Sun’s
energy is distributed unevenly on Earth’s surface due to the tilt of Earth’s
axis of rotation.
• Angle of rotation results in equatorial areas receiving more solar energy than
those near the poles.
• The tropical oceans and land masses absorb a great deal more heat than
the other regions of Earth.
• The atmosphere and oceans act together to redistribute this heat.
The Climate System

9. • Continual redistribution of heat is modified by the planet’s west to east
rotation.
• Coriolis force associated with the planet’s spherical shape, giving rise to the
high jet streams and the prevailing westerly trade winds.
• The winds, in turn, along with Earth’s rotation, drive large ocean currents.
• Ocean currents redistribute warmers waters away from the tropics towards
the poles.
• The ocean and atmosphere exchange heat and water (through evaporation
and precipitation), carbon dioxide and other gases.
• These complex, changing atmospheric and oceanic patterns help determine
weather and climate.

10. • Five layers of atmosphere surround Earth, from surface to
outer space.
• The lowest layer (troposphere) extends from ground level
to 10–18km. The height varies with the amount of solar
energy reaching Earth; it is lowest at the poles and highest
near the equator. On average, air temperature in the
troposphere decreases 7 °C for each kilometre increase in
altitude, as atmospheric pressure decreases.
• The level at which temperature stops decreasing with
height is called the tropopause, and temperatures here
can be as low as -58°C.
• The next layer (stratosphere) extends from the tropopause
to about 50km above the surface, with temperatures
slowly increasing to about 4 °C at the top. A high
concentration of ozone occurs naturally in the
stratosphere at an altitude of about 24km.
• Ozone in this region absorbs most of the Sun’s ultraviolet
rays that wouldbe harmful to life on Earth’s surface.
• Above the stratosphere are three more layers
(mesosphere, thermosphere and exosphere)
characterized by falling, then rising, temperature patterns.

11. • Overall, the atmosphere reduces the amount of
sunlight reaching Earth’s surface by about 50%.
• Greenhouse gases compose about 2% of the
atmosphere. In a clear, cloudless atmosphere
greenhouse gases absorb about 17% of the
sunlight passing through it.
• Clouds reflect about 30% of the sunlight falling
on them and absorb about 15% of the sunlight
passing through them.
• Earth’s surface absorbs some sunlight and
reradiates it as long-wave (infrared) radiation.
• Some of this infrared radiation is absorbed by
atmospheric greenhouse gases and reradiated
back to Earth, thereby warming the surface of
Earth by more than would be achieved by
incoming solar radiation alone.
• This atmospheric greenhouse effect is the
warming process that raises the average
temperature of Earth to its present 15 °C.

12. • Recognizing that global climate change posed a range of potentially
serious, often new, hazards to human societies, The World Meteorological
Organization (WMO) and The United Nations Environment Programme
(UNEP) established the Intergovernmental Panel on Climate Change
(IPCC) in 1988.
• The role of the IPCC is to assess published scientific literature on how
human-induced changes to the gaseous composition of the lower
atmosphere, caused by an increase in the emission of greenhouse gases,
are likely to influence world climatic patterns;
• How this in turn would affect a range of systems and processes important to
human societies (including human health); and what range of economic and
social response options exists.
Intergovernmental Panel on Climate Change (IPCC)

13. The IPCC has three Working Groups and a Task Force :
• Working Group I assesses the scientific aspects of the climate
system and climate change.
• Working Group II addresses the vulnerability of socioeconomic and
natural systems to climate change, the resultant negative and
positive impacts of climate change and the options for adaptations
to lessen the impacts.
• Working Group III assesses options for limiting greenhouse gas
emissions and otherwise mitigating climate change.
• The Task Force on National Greenhouse Gas Inventories defines
and disseminates standardized methods for countries to calculate
and report Green House Gas emissions.

14. The latest report from the Intergovernmental Panel on Climate
Change (IPCC):
1. Human-induced warming has apparently begun.
2. Acoherent pattern of changes in simple physical and biological systems
has become apparent across all continents.
3.The anticipated average surface temperature rise this century, within the
range of 1.4 to 5.8 °C, would be a faster.
The IPCC also reported that even if humankind manages to curb
excess greenhouse gas emissions within the next half-century, the world’s
oceans will continue to rise for up to 1000 years, reflecting the great inertial
processes as heat is transferred from surface to deep water. By that time the
sea level rise would have approximated 1–2 metres.

15. Challenges for Scientists:
The biggest challenge is scale. Both the geographical spread of
climate-related health problems and the much elongated time spans that often
apply, are largely unfamiliar to public health researchers. Research on climate
change typically is conducted on three time-scales:
1. Relatively short periods between altered climate (expressed as weather)
and the effects on health.
2. Intermediate time periods that include recurring, inter-annual events like
ElNiño and La Niña.
3. Longer intervals (decades or centuries) between the release of greenhouse
gases and subsequent change in the climate. This category of research is
most troublesome to standard epidemiological methods

16. The main tasks of public health science in assessing the potential health
effects of climate variability and change include:
• Establishing baseline relationships between weather and health.
• Seeking evidence for early effects of climate change.
• Developing scenario-based models.
• Evaluating adaptation options.
• Estimating the coincidental benefits and costs of mitigation and adaptation.

17. Climate change Land degradation
Stratospheric
ozone depletion
Freshwater decline
Biodiversity
loss and ecosystem
function
HUMAN HEALTH
Diverse Pathways
Deaclines in phenotypic,
genetic materials and diverse
‘goods and services
Water quantity and safety
Agroecosystem Productivity
Conflict
Altered precipitation
Impacts on Health :

20. Environmental
changes
Pathway of effect Example diseases
Dams, canals,
irrigation
↑ Snail host habitat, human contact Schistosomiasis
↑ Breeding sites for mosquitoes Malaria
↑ Larval contact due to moist soil Helminthiasies
↓ Blackfly breeding, ↓ disease River blindness
Agricultural
intensification
Crop insecticides and ↑ vector resistance Malaria
↑ Rodent abundance, contact Venezuelan haemorraghic fever
Urbanization,
urban crowding
↓ Sanitation, hygiene ; ↑ water contamination Cholera
Water-collecting trash, ↑ Aedes aegypti mosquito breeding sites Dengue
↑ Proximity, sandfly vectors Cutaneous leishmaniasis
Examples of environmental changes and possible effects on infectious diseases.

21. Environmental
changes
Pathway of effect Example diseases
Deforestation and
new habitation
↑ Breeding sites and vectors, immigration of susceptible
people
Malaria
↑ Contact, breeding of vectors
Oropouche
↑ Contact with sandfly vectors Visceral leishmaniasis
Reforestation ↑ Tick hosts, outdoor exposure Lyme disease
Ocean warming ↑ Toxic algal blooms Red tide
Elevated
precipitation
↑ Pools for mosquito breeding Rift valley fever
↑ Rodent food, habitat, abundance Hantavirus pulmonary syndrome
Examples of environmental changes and possible effects on infectious diseases.

22. Event Type Description Potential health impact
Heavy precipitation
event
meteorological “extreme event”
increased mosquito abundance or
decreased
(if breeding sites are washed away)
Flood hydrological
river/stream over
tops its banks
changes in mosquito abundance
contamination of surface water
Flood social
property or crops
damaged
changes in mosquito abundance
contamination of water with faecal matter
and rat urine (leptospirosis).
Flood
catastrophic
flood/”disaster”
Flood leading to
>10killed, and/or 200
affected, and/or
government call for
external assistance.
changes in mosquito abundance
contamination of water with faecal matter
and rat urine andincreased risk of respiratory
and diarrhoeal disease deaths (drowning)
injuries health effects associated with
population displacement loss of food supply
psychosocial impacts
Mechanism by which above-average rainfall can affect health.

23. Event Type Description Potential health impact
Drought
meteorological
evaporation exceeds water
absorption,soil moisture
decreases
evaporation exceeds water absorption,breeds
in dried up river beds, for example. Several
indices have been developed
based on meteorological variables,
e.g. Palmer Drought Severity Index.
Drought
agricultural
Drier than normal conditions
leading to decreased crop
production
depends on socioeconomic factors, i.e.other
sources of food available and the means to
acquire them
Drought social
reduction in food supply or
income, reduction in water
supply and quality
food shortage, illness, malnutrition (increases
risk of infection)
increased risk of disease associated
with lack of water for hygiene.
Drought
food
shortage/amine/
drought disaster
food shortage leading to deaths
>10 killed, and/or 200 affected,
or government call for
external assistance.
deaths (starvation) malnutrition (increases
risk of infection) health impacts associated
with population displacement.
Mechanisms by which below-average rainfall can affect health

24. Effects of weather and climate on vector and rodent-borne diseases:
Temperature effects on selected vectors and vector-borne pathogens.
Vector
• survival can decrease or increase depending on species;
• some vectors have higher survival at higher latitudes and altitudes with higher
temperatures;
• changes in the susceptibility of vectors to some pathogens
e.g. higher temperatures reduce size of some vectors but reduce activity of others;
• changes in the rate of vector population growth;
• changes in feeding rate and host contact (may alter survival rate);
• changes in seasonality of populations.
Pathogen
• decreased extrinsic incubation period of pathogen in vector at higher temperatures
• changes in transmission season
• changes in distribution
• decreased viral replication.

25. Effects of changes in precipitation on selected vector-borne pathogens
Vector
• increased rain may increase larval habitat and vector population size by creating
new habitat
• excess rain or snowpack can eliminate habitat by flooding, decreasing vector
population
• low rainfall can create habitat by causing rivers to dry into pools (dry season malaria)
• decreased rain can increase container-breeding mosquitoes by forcing increased
water storage
• epic rainfall events can synchronize vector host-seeking and virus transmission
• increased humidity increases vector survival; decreased humidity decreases vector
survival.
Pathogen
Few direct effects but some data on humidity effects on malarial parasite development
in the anopheline mosquito host.

26. Ozone Depletion
The ozone layer is destroyed by ozone-depleting substances (ODS) when those
chemicals are released into the atmosphere and then react with the ozone
molecules.
Elevated ultraviolet radiation reaching the earth as a result of ozone depletion
can have major impacts on life and nature, including skin cancer and cataracts
and weakened immune systems.
It also can damage terrestrial plant life, including crops, and aquatic
ecosystems.
Examples:
1. Chlorofluorocarbons (CFCs) e.g. CFC-12(aka R-12 or F-12)
2. Halons (Bromochlorofluorocarbons) e.g.Halon 1301
3. Carbon tetrachloride
4. Methyl chloroform
5. Hydrochlorofluorocarbons (HCFCs) e.g.HCFC-22 (aka R-22 or F-22)
6. Hydrobromofluorocarbons (HBFCs)
7. Bromochloromethane

27. Effects of solar ultraviolet radiation on the health of human beings:
Effects on skin
• Malignant melanoma
• Non-melanocytic skin cancer—basal cell carcinoma, squamous cell carcinoma
• Sunburn
• Chronic sun damage
• Photodermatoses.
Effects on the eye
• Acute photokeratitis and photoconjunctivitis
• Climatic droplet keratopathy
• Pterygium
• Cancer of the cornea and conjunctiva
• Lens opacity (cataract)—cortical, posterior subcapsular
• Uveal melanoma
• Acute solar retinopathy
• Macular degeneration.

28. Effect on immunity and infection
• Suppression of cell mediated immunity
• Increased susceptibility to infection
• Impairment of prophylactic immunization
• Activation of latent virus infection.
Other effects
• Cutaneous vitamin D production
— prevention of rickets, osteomalacia and osteoporosis
— possible benefit for hypertension, ischaemic heart disease and tuberculosis
— possible decreased risk for schizophrenia, breast cancer, prostate cancer
— possible prevention of Type 1 (usually insulin dependent) diabetes
• Non-Hodgkin’s lymphoma
• Altered general well-being
— sleep/wake cycles
— seasonal affective disorder
— mood.
Indirect effects
• Effects on climate, food supply, infectious disease vectors, air pollution, etc.

29. The Montreal Protocol
• The Montreal Protocol on Substances that deplete the Ozone Layer is an
international treaty designed to protect the ozone layer by phasing out the
production of numerous substances believed to be responsible for ozone
depletion.
• Opened for signature on September 16, 1987
• Came into force on January 1, 1989,
• first meeting in Helsinki, May 1989.
Since then, it has undergone 8 revisions,
1990 London 1995 Vienna
1991 Nairobi 1997 Montreal
1992 Copenhagen 1999 Beijing
1993 Bangkok 2016(kigali)
• It is believed that if the international agreement is adhered to, the ozone layer is
expected to recover by 2050.

30. Phase-out Schedule for
INDIA
as per Montreal Protocol
Ozone-depleting
substance
Total Phase-
out by
Chloro Fluoro Carbons 2010
Halons 2010
Hydro bromo fluoro Carbons 1996
Carbon Tetra Chloride 2010
Methyl Bromide 2015
Hydro Chloro Fluoro Carbons 2040

31. Conclusions and Recommendations
• The contribution of short-term climate variability to disease incidence needs
further research.
• Early warning systems for prediction of disease outbreaks, heatwaves and
other extreme events need to be developed further and validated.
• Identifying areas where first effects of climate change on human health will
be apparent.
• Improving estimates of climate change impacts by a combination of
anticipated trends in adaptive capacity and climate scenarios.
• Identifying the most helpful ways of expressing uncertainties associated with
studies of climate change and health.
• Further modelling of relationships between extreme events and health
impacts, especially in poor countries.
• Improved understanding of factors affecting vulnerability to climate extremes.

32. A successful policy-focused assessment of the potential health impacts of
climate change should have several key characteristics. These include the
following :
• Multidisciplinary assessment team.
• Each assessment to answer in a timely fashion questions asked by
stakeholders in the public health community.
• Evaluation of risk management adaptation options.
• Identification and prioritization of key research gaps.
• Characterization and explanation of uncertainties and their implications for
decision-making.
• Development of tools in support of decision-making processes.

33. THANK YOU...
“If you really think the ENVIROMENT
is less important than economy
try holding your BREATH while you
count your money”.
Dr. Guy
McPherson.