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Basic Climate Change
These lectures are adapted from
USAID LEAF’s Regional Climate Change Curriculum
Nguyen Le Ai Vinh, PhD.
Biology Faculty, Vinh University
Nghe An, 2015 106/03/2015
Basic Climate Change
Chapter 1.
Introduction to Climate Science and Introduction to Climate Science and
Climate Change
206/03/2015
Learning objectives
At the end of this session, learners will be able to:
• Differentiate between climate change and climate
impacts
• Explain how climate impacts are discerned
3
• Explain how climate impacts are discerned
• Analyze how impacts of climate change combine
with other impacts to people and the environment
• Explain what impact pathways are and how to
discern and evaluate them
06/03/2015
Outline
1. Weather and Climate2. Climate System3. Climate Variation3. Climate Variation4. Climate Change
406/03/2015
List the following things about climate science and
climate change:
3 things you know about the
topic
2 things you want to
learn/don’t know
1 question you want to ask
Pair yourself to the one sitting on your right hand site and discuss
your answers.06/03/2015 5
1. Weather and Climate
a) Why study climate?
– Reasons
– Case study: Biomes of the world
b) Weather
– Definition– Definition
– Characteristics
– Meteorology
c) Climate
– Definition
– Characteristics
– Climatology
606/03/2015
Some reasons:
1. Climate determines the type and location of
human-managed ecosystems, such as
agricultural farmlands.
2. Climate affects the weathering of rock, the type 2. Climate affects the weathering of rock, the type
of soil that forms, and the rate of soil formation.
06/03/2015 7
3. Helps to determine the quantity and quality of
water available for human use.
4. Determines the severity of droughts, storms, and
floods.
Largely determines the nature and locations of 5. Largely determines the nature and locations of
biomes -major terrestrial ecosystems, defined
based on their plant communities.
6. ….
06/03/2015 8
906/03/2015
1006/03/2015
Place Average Temperature oCAnnual Precipitation
(cm)Biome
La Selva, Costa Rica 22.1 403
Marietta, Ohio 12 105
Pasadena California 18.2 51.8Ferron, Utah 8.8 20.9Tucson, Arizona 21.1 21.9
Santa Rosa, Costa Rica 26 165
11
Santa Rosa, Costa Rica 26 165
Brazzaville, Congo 25 137
Lambarene, Gabon 25.7 195
Amauulu, Hawaii 20 410Toolik Lake, Alaska -8.8 18Beijing, China 11.8 63.5
Seoul, South Korea 11.2 137
Archbold Biological Station
29.1 131
Everglades National Park (Flamingo)
28.1 159
06/03/2015
Place Average Temperature oCAnnual Precipitation
(cm)Biome
La Selva, Costa Rica 22.1 403 Tropical Rain Forest
Marietta, Ohio 12 105Temperate Deciduous Forest
Pasadena California 18.2 51.8 SavannaFerron, Utah 8.8 20.9 DesertTucson, Arizona 21.1 21.9 Subtropical Desert
Santa Rosa, Costa Rica 26 165 Tropical Seasonal Forest
12
Santa Rosa, Costa Rica 26 165 Tropical Seasonal Forest
Brazzaville, Congo 25 137 Tropical Seasonal Forest
Lambarene, Gabon 25.7 195 Tropical Seasonal Forest
Amauulu, Hawaii 20 410 Tropical Rain ForestToolik Lake, Alaska -8.8 18 TundraBeijing, China 11.8 63.5 Temperate Grassland
Seoul, South Korea 11.2 137Temperate Deciduous Forest
Archbold Biological Station
29.1 131 Tropical Seasonal Forest*
Everglades National Park (Flamingo)
28.1 159 Tropical Seasonal Forest*
06/03/2015
What is Weather?
What is Climate?
06/03/2015 13
Definition:
� The actual state of the atmosphere in a period of
several hours up to a few days (in a given place)
(Gramelsberger & Feichter, 2011).
06/03/2015 14
� Temperature
� Wind
� Clouds
� Precipitation/
Humidity/RainHumidity/Rain
� What we are
feeling in present
time and a given
place →
METEOROLOGY
(The science of
weather).06/03/2015 15
1. The field of atmospheric science which is most well-
known and of practical importance to the general
public is meteorology, the study of weather.
2. Meteorology is usually concerned only with the Meteorology is usually concerned only with the
lowest region of the atmosphere, the troposphere.
3. Weather is influenced not only by vertical, diurnal,
and seasonal variations of atmospheric density and
temperature, and of solar heating, but also by
horizontal variations over Earth’s surface.06/03/2015 16
4. Atmospheric winds and circulation are influenced
by Earth’s rotation, and by surface conditions (i.e.
whether land or sea, topography, and surface
temperature).temperature).
5. The advent of weather-monitoring satellites, and of
supercomputers, have greatly facilitated the science
and application of meteorology in recent years.
06/03/2015 17
Definitions
� A statistical description in terms of the mean and
variability of relevant quantities over a period
ranging from months to thousands or millions of ranging from months to thousands or millions of
years (IPCC).
� The classical period is 30 years, which are most often
surface variables such as temperature, precipitation,
and wind. Climate in a wider sense is the state,
including a statistical description, of the climate
system (World Meteorological Organization, WMO).
06/03/2015 18
� Climate element: It is any physical quantity (e.g.,
temperature, rain, iceberg frequency, hurricane
track…)
� Climate element exhibits time and space variations.
19
Climate element exhibits time and space variations.
� Climate is defined to include all the statistical
properties of the system consisting of the
atmosphere, land surfaces and oceans (climate
system)
� The climate is always changing, always has changed.
06/03/2015
1,000,000 year time scales
Plate tectonics
100,000 year time scales
Orbital variations and glacial
periodsperiods
100-10 year time scales
Events like the Little Ice Age and
Medieval Warm Period
10-5 year time scales
El Niño – La Niña cycles
06/03/2015 20
500 mya 400 mya
300 mya 200 mya
Ice sheets can only grow when continents are at the poles.06/03/2015 21
A B
C
06/03/2015 22
EARTHEARTH
The Earth’s orbit is almost
a perfect circle with slight
variations every 100,000
and 400,000 years.
06/03/2015 23
06/03/2015 24
A B
C
06/03/2015 25
06/03/2015 26
� The output of energy
from the sun has been
monitored by satellites
for thirty years and has for thirty years and has
NOT increased during
this period of rapid
global warming.
06/03/2015 27
06/03/2015 28
2806/03/2015
Chance are better than 50%
El Nino conditions will
develop this year (2014-
29
develop this year (2014-
2015).
NOAA's Climate Prediction Center
06/03/2015
2. Climate System
a) Components of the Climate System
b) Interactions among the components
3106/03/2015
Five major
components:
1. The atmosphere
2. The hydrosphere
Air
WaterLand
Ice
2. The hydrosphere
3. The cryosphere
4. The lithosphere/
The land surface
5. Biosphere
Life
Land
06/03/2015 32
� It is the most unstable and rapidly changing part of the system.
� It is composed mainly of nitrogen (N2, 78.1% volume mixing ratio), oxygen (O2, 20.9% volume mixing ratio, and
Air
(O2, 20.9% volume mixing ratio, and argon (Ar, 0.93% volume mixing ratio).
� Green house gases such as carbon dioxide (CO2), methane (CH4), nitrousoxide (N2O) and ozone (O3),
� It also contains solid and liquid particles (aerosols) and clouds.
06/03/2015 33
� It is the component comprising all liquid surface and subterranean water, both fresh water and saline water.
� The oceans cover approximately 70% of the Earth’s surface.They store and transport a large amount
Water
� They store and transport a large amount of energy and dissolve and store great quantities of carbon dioxide.
� They function as a regulator of the Earth’s climate and as a source of natural climate variability, in particular on the longer time-scales.06/03/2015 34
� The cryosphere includes the ice sheets of Greenland and Antarctica, continental glaciers and snow fields, sea ice and permafrost.
� It derives its importance to the climate system from its high reflectivity (albedo) for solar
Ice
from its high reflectivity (albedo) for solar radiation, its low thermal conductivity, its large thermal inertia and, especially, its critical role in driving deep ocean water circulation.
� Because the ice sheets store a large amount of water, variations in their volume are a potential source of sea level variations
06/03/2015 35
� Vegetation and soils at the land surface control how energy received from the Sun is returned to the atmosphere. Some is returned as long-wave (infrared) radiation, heating the atmosphere as the land surface warms.
� Some serves to evaporate water. Because
Land
� Some serves to evaporate water. Because the evaporation of soil moisture requires energy, soil moisture has a strong influence on the surface temperature.
� The texture of the land surface (its roughness) influences the atmosphere dynamically as winds blow over the land’s surface.
06/03/2015 36
� The marine and terrestrial biospheres have a
major impact on the atmosphere’s
composition.
� The biota influence the uptake and release of
greenhouse gases.
Life
� Through the photosynthetic , plants store
significant amounts of carbon from carbon
dioxide.
� Other biospheric emissions (volatile organic
compounds - VOC) which may have important
effects on atmospheric chemistry, on aerosol
formation and therefore on Climate.06/03/2015 37
� Many physical, chemical and biological interaction processes occur among the various components of the climate system on a wide range of space and time scales, making the system extremely complex.
� Examples:� The atmosphere and the oceans are strongly coupled and
exchange, among others, water vapour and heat through evaporation.
� Sea ice hinders the exchanges between atmosphere and oceans;
� The biosphere influences the carbon dioxide concentration by photosynthesis and respiration, which in turn is influenced by climate change
06/03/2015 38
Air Ice
Water
Life
Land
06/03/2015 39
06/03/201540
3. Climate Variation
• Natural Forcing of the Climate System
• The natural variability of the climate
• Dynamics of the Earth
4106/03/2015
a) The Sun and the global energy balance
b) The natural greenhouse effect
c) Radiative forcing and forcing variability
06/03/2015 42
� The ultimate source of energy that drives the climate system is radiation from the Sun. About half of the radiation is in the visible short-wave part of the electromagnetic spectrum. The other half is mostly in the near-infrared part, with some in the ultraviolet part of the spectrum.
� Each square metre of the Earth’s spherical surface outside the atmosphere receives an average throughout the year of 342 Watts of solar radiation, 31% of which is immediately reflected back into space by clouds, by the atmosphere, and by the Earth’s surface. The remaining 235 Wm−2 is partly absorbed by the atmosphere but most (168 Wm−2) warms the Earth’s surface: the land and the ocean.06/03/2015 43
� The Earth’s surface returns the heat to the atmosphere, partly as infrared radiation.
� For a stable climate, a balance is required between incoming solar radiation and the outgoing radiation emitted by the climate system. Therefore the climate system itself by the climate system. Therefore the climate system itself must radiate on average 235 Wm−2 back into space.
06/03/2015 44
06/03/201545
� The atmosphere contains several trace gases which absorb and emit infrared radiation. These so-called greenhouse gases absorb infrared radiation, emitted by the Earth’s surface, the atmosphere and clouds, except in a transparent part of the spectrum called the “atmospheric a transparent part of the spectrum called the “atmospheric window”.
� GHGs trap heat within the atmosphere. This mechanism is called the natural greenhouse effect.
� Clouds also play an important role in the Earth’s energy balance and in particular in the natural greenhouse effect.
06/03/2015 46
� In an equilibrium climate state the average net
radiation at the top of the atmosphere is zero. A
change in either the solar radiation or the infrared
radiation changes the net radiation. The corresponding
imbalance is called “radiative forcing”.imbalance is called “radiative forcing”.
06/03/2015 47
� External forcings, such as the solar radiation or the large
amounts of aerosols ejected by volcanic eruption into the
atmosphere, may vary on widely different time-scales, causing
natural variations in the radiative forcing. These variations may
be negative or positive. In either case the climate system must
react to restore the balance. A positive radiative forcing tends react to restore the balance. A positive radiative forcing tends
to warm the surface on average, whereas a negative radiative
forcing tends to cool it. Internal climate processes and
feedbacks may also cause variations in the radiative balance by
their impact on the reflected solar radiation or emitted infrared
radiation, but such variations are not considered part of
radiative forcing.
06/03/2015 48
� Internally and externally induced climate
variability
� Feedbacks and non-linearities
� Global and hemispheric variability� Global and hemispheric variability
� Regional patterns of climate variability
06/03/2015 49
IPCC, 3rd AR:
� Climate variability refers to variations in the mean state
and other statistics (such as the occurrence of extremes,
etc.) of the climate on all temporal and spatial scales etc.) of the climate on all temporal and spatial scales
beyond that of individual weather events. Variability may
be due to natural internal processes within the climate
system (internal variability), or to variations in natural or
anthropogenic external forcing (external variability)
06/03/2015 50
� When variations in the external forcing occur, the response time of the
various components of the climate system is very different. With regard
to the atmosphere, the response time of the troposphere is relatively
short, from days to weeks, whereas the stratosphere comes into
equilibrium on a time-scale of typically a few months. Due to their large
heat capacity, the oceans have a much longer response time, typically heat capacity, the oceans have a much longer response time, typically
decades but up to centuries or millennia. The response time of the
strongly coupled surfacetroposphere system is therefore slow
compared with that of the stratosphere, and is mainly determined by
the oceans. The biosphere may respond fast, e.g. to droughts, but also
very slowly to imposed changes. Therefore the system may respond to
variations in external forcing on a wide range of space- and timescales.
The impact of solar variations on the climate provides an example of
such externally induced climate variations.06/03/2015
51
� But even without changes in external forcing, the
climate may vary naturally, because, in a system of
components with very different response times and
non-linear interactions, the components are never in
equilibrium and are constantly varying. An example of equilibrium and are constantly varying. An example of
such internal climate variation is the El Niño-Southern
Oscillation (ENSO), resulting from the interaction
between atmosphere and ocean in the tropical Pacific.
06/03/201552
� A process is called a feedback when the result of the process
affects its origin thereby intensifying (positive feedback) or
reducing (negative feedback) the original effect. An
important example of a positive feedback is the water
vapour feedback in which the amount of water vapour in the
atmosphere increases as the Earth warms. This increase in
turn may amplify the warming because water vapour is a
strong greenhouse gas. A strong and very basic negative
feedback is radiative damping: an increase in temperature
strongly increases the amount of emitted infrared radiation.
This limits and controls the original temperature increase.
06/03/2015 53
� Many processes and interactions in the climate system
are non-linear. That means that there is no simple
proportional relation between cause and effect. A
complex, non-linear system may display what is
technically called chaotic behaviour. Thistechnically called chaotic behaviour. This
06/03/2015 54
06/03/2015 55
Let Walk through:
Global Climate System Video
06/03/2015 56
1. Atmospheric Circulation
2. Ocean Circulation
3. Land Surface Processes
4. Vegetation - Carbon4. Vegetation - Carbon
5. Snow and Ice
6. El Niño
7. La Niña
06/03/2015 57
a) The Sun and the global energy balance
b) The natural greenhouse effect
c) Radiative forcing and forcing variability
06/03/2015 58
� What atmospheric circulation?
� What is Coriolis effect?
06/03/2015 59
1. The atmospheric convection cells play to convey
heat from the warm equatorial region to the cold
polar regions.
2. Warm air rises near the equatorial latitudes. 2. Warm air rises near the equatorial latitudes.
3. When the rising warm air reaches the peak of the
troposphere, it moves toward the poles, and when
the air cools, it flows and becomes dense enough to
sink at latitudes of about 30oN or 30oS.
06/03/2015 60
4. When this cold air reaches the Earth's surface, it is
moved toward the equator, and it then warms and
rises.
5. Where the air is rising or sinking at the equator, 30o, 5. Where the air is rising or sinking at the equator, 30o,
50o, 60o, and at the poles.
06/03/2015 61
� Comes from the Earth’s rotation influencing the
direction of the air movement.
� The tendency of a free movement of object to appear to
move to the right in the northern hemisphere and to
the left in the southern hemisphere due to Earth's the left in the southern hemisphere due to Earth's
rotation.
� Air moves horizontally from high to low pressure zones,
forming the major wind belts, including the trade winds,
between the equator and 30oN and 30oS; between 30oN
and 30oN and 50o to 60oN and 50o to 60oS; and the polar
winds.06/03/2015 62
Jet Stream occurs
here
Jet Stream occurs
here
06/03/2015 63
Video on
Atmospheric Circulation
06/03/2015 64
1. The oceans play a large part of in determining the
existing climate of the Earth.
2. It seems to have a crucial influence on climate
change due to human activities.
3. Ocean and atmosphere are close interactions and
have a strong system.
06/03/2015 65
4. Oceans have high capacity to contain heat
compared with the atmosphere driving to gradually
raise temperature in the oceans.
5. Oceans redistribute heat throughout the climate
system through their internal circulation.
06/03/2015 66
06/03/2015 67
Video on
Ocean Circulation
06/03/2015 68
06/03/2015 69
Carbon only affects climate when it is in the atmosphere
Gases move through the Earth reservoirs:
� Atmosphere
� Biosphere (living things)� Biosphere (living things)
� Lithosphere (solid earth)
� Hydrosphere (freshwater and oceans)
06/03/2015 70
06/03/2015 71
Video on
Carbon Cycle
06/03/2015 72
� The presence or absence of snow and ice affects
warming and cooling over the Earth’s surface,
influencing the Earth’s energy balance.
Changes in snow and ice cover affect freshwater � Changes in snow and ice cover affect freshwater
availability, air temperatures, sea levels, ocean
currents, and storm patterns.
06/03/2015 73
� A reduction in snow cover and ice causes the Earth’s
surface to absorb more energy from the sun
(decreased albedo), which is a positive feedback,
causing stronger warmingcausing stronger warming
06/03/2015 74
� What is El Niño?
� El Niño is the prolonged warming in the Pacific
Ocean sea surface temperature compared with
the average value. It is a warming of at least 0.5°C
(0.9°F) averaged over the east-central tropical (0.9°F) averaged over the east-central tropical
Pacific Ocean.
� A pattern of ocean surface temperature in the
Pacific off the coast of South America, which has a
large influence on world climate (Houghton,
2009).
06/03/2015 75
� The first signs of an El Niño are:
1. Rise in surface pressure over the Indian Ocean,
Indonesia and Australia
2. Fall in air pressure over Tahiti and the rest of the 2. Fall in air pressure over Tahiti and the rest of the
central and eastern Pacific Ocean
3. Trade winds in the south Pacific weaken or head
east.
06/03/2015 76
� The first signs of an El Niño are:
4. Warm air rises near Peru, causing rain in the
northern Peruvian deserts
5. Warm water spreads from the west Pacific and 5. Warm water spreads from the west Pacific and
the Indian Ocean to the east Pacific. It takes the
rain with it, causing extensive drought in the
western Pacific and rainfall in the normally dry
eastern Pacific.
06/03/2015 77
El Niño: Warm water
pool approaches South
American coast.
Absence of cold
upwelling increases
warmingwarming
06/03/2015 78
06/03/2015 79
La Niña: Equatorial
winds gather warm
water pool toward the
west. Cold water
upwells along South
American coastAmerican coast
06/03/2015 80
06/03/2015 81
� El Niño in general occurs in every 3 to 7 years and
appears around Christmas period.
� Droughts and floods occurring almost all continents
are associated with El Niño.are associated with El Niño.
� ENSO caused by the shift of the atmospheric-oceanic
conditions, due to the way the oceans store and
transport heat.
06/03/2015 82
SST °C SST °C
El NiñoLa Niña
DroughtFlood
06/03/2015 83
Video clip on
El Niño and La Niña
https://www.youtube.com/watch?v=7FVZrw7bk1w
06/03/2015 84
4. Climate Change
• What is Climate Change?• The primary indicators of climate change• Warming of Climate.
8506/03/2015
IPCC, 3rd AR:
Climate change: a statistically significant variation in
either the mean state of the climate or in its
variability, persisting for an extended period variability, persisting for an extended period
(typically decades or longer).
Climate change may be due to natural internal
processes or external forcings, or to persistent
anthropogenic changes in the composition of the
atmosphere or in land use .
06/03/2015 86
UNFCCC, Article 1:
“climate change”: “a change of climate which is
attributed directly or indirectly to human activity
that alters the composition of the global atmosphere that alters the composition of the global atmosphere
and which is in addition to natural climate variability
observed over comparable time periods.”
06/03/2015 87
IPCC, 3rd AR:
� Climate variability refers to variations in the mean
state and other statistics (such as the occurrence of
extremes, etc.) of the climate on all temporal and extremes, etc.) of the climate on all temporal and
spatial scales beyond that of individual weather
events. Variability may be due to natural internal
processes within the climate system (internal
variability), or to variations in natural or
anthropogenic external forcing (external variability)
06/03/2015 88
Seven of these indicators would be expected to increase in a warming world and observation show that
they are, in fact, increasing. Three would be expected to decrease and they are, in fact, decreasing.06/03/2015 89
� Increases in global sea and air temperatures
� Widespread melting of snow and ice
� Rising global sea level
06/03/2015 90
What can/cannot be controlled…
� Solar system?
� Earth system?
� Earth Dynamics?
If something can, how? If cannot, how?
06/03/2015 91
� Most mountain glaciers are getting smaller.
� Snow cover is retreating earlier in the spring.
� Sea ice in the Arctic is shrinking in all seasons, most
dramatically in summer.
Reductions are in the permafrost, seasonally frozen � Reductions are in the permafrost, seasonally frozen
ground and river and lake ice.
� Important coastal regions of ice sheets on Greenland
and West Antartica, and the glaciers of the Antartic
Peninsular, are thinning and contributing to sea level
rise.06/03/2015 92
06/03/2015 93
� The change in sea ice in the previous slide:
� Discuss: How does this change affect the heating of
the Earth’s atmosphere?
06/03/2015 94
Two major causes of global sea level rise:
� Thermal expansion of the oceans (water expands as it
warms)
Loss of land-based ice due to increased melting (glaciers � Loss of land-based ice due to increased melting (glaciers
and continental ice caps)
06/03/2015 95
Warming of the climate
system evidence:
� Increases in global
average air and average air and
ocean temperature
� Widespread melting
of snow and ice
� Rising global mean
sea level
06/03/2015 96
� Importance of understanding and studying of climate, its
characteristics,
� Key elements and dynamics to determine climatic
condition,
97
condition,
� Climate system,
� Energy budget,
� El Niño and La Niña,
� Climate change and global warming.
06/03/2015
� What was useful?
� What is missing?
� How did you, or would you, modify the materials to make
them better fit your instructional context? them better fit your instructional context?
� Please share your experience and modifications here:
06/03/2015 98