metr112 global climate change professor menglin jin san jose state university december 1, 2008

METR112 Global Climate Change

Professor Menglin JinSan Jose State University

December 1, 2008

Scope for Final Exam: Materials discussed after the mid-term

Materials: Lectures (Lectures 8-12) most important!Homework 3 and 4 very importantVideo will be only briefly touched

Exam format: half multiple choiceshalf short sentence answers

Weight of Final exam: will be scored as 100 pointsbut will be weighted as 35% of the total class grade

3 MET 112 Global Climate MET 112 Global Climate ChangeChange

MET 112 Global Climate Change -

Natural Climate ForcingProfessor Menglin Jin

San Jose State University

Outline – Paleoclimate – temperature and CO2 Natural forcing for temperature change Features for Glacier and inter-glacier Activity


PaleoclimateA lead to


Earth geological time scale

Paleo : Greek root means “ancient”

Modern age, ice age, last 2 million years

Age of dinosaurs

From the formation of earth to the evolution of macroscopic hard-shelled animals

Animal explosion of diversity


Cosmic rays produce C14C14 has half-life of 5730 years and constitutes about one percent of the carbon in

an organism.When an organism dies, its C14 continues to decay.The older the organism, the less C14

C14 and O18 proxy

O18 is heavier, harder to evaporate. As temperature decreases (in an ice age), snow deposits contains lessO18 while ocean water and marine organisms (CaCO3) contain more O18

The O18/ O16 ratio or δO18 in ice and marine deposits constitutes a proxy thermometer that indicates ice ages and interglacials.

Low O18 in ice indicates it was deposited during cold conditions worldwide, while low O18 in marine deposits indicates warmth

C14 dating proxy

O18 temperature proxy


Natural Climate Change

External Forcing:–

Internal Forcing:–

The agent of change is outside of the Earth-atmosphere system

The agent of change is within the Earth-atmosphere system itself


Continental drift http://www.mun.ca/biology/scarr/Pangaea.html

In 1915, German scientist Alfred Wengener first proposed continental drift theory and published book On the Origin of Continents and Oceans

Continental drift states:In the beginning, a supercontinent called Pangaea. During Jurrasic, Pangaea breaks up into two smaller supercontinents, Laurasia and Gondwanaland,. By the end of the Cretaceous period, the continents were separating into land masses that look like our modern-day continents


Consequences of continental drift on climate

Polarward drifting of continents provides land area for ice formation cold climate

Antarctica separated from South America reduced oceanic heat transport cold climate

Joint of North and South America strengthens Gulf Stream and increased oceanic heat transport warm climate

Uplift of Tibetan Plateau Indian monsoon


Warm during Cretaceous

Psulsen 2004, nature

The Arctic SST was 15 oC or higher in mid and last Cretaceous. Global models can only represent this feature by restoring high level of CO2

High CO2 may be responsible for the initiation of the warming

Higher water vapor concentration leads to increased latent heat transport to high latitudes

Decreased sensible heat transport to high latitudes results from decreased meridional temperature gradient

Thermal expansion of sea water increased oceanic heat transport to high latitudes

being the last period of the Mesozoic era characterized by continued dominance of reptiles, emergent dominance of angiosperms, diversification of mammals, and the extinction of many types of organisms at the close of the period

Cretaceous


Short-term forcing: The kinetic energy of thebollide is transferred to the atmosphere sufficient to warm the global mean temperature near the surface by 30 K over the first 30 days The ejecta that are thrown up by the impact return to Earth over several days to weeks produce radiative heating. Long-term forcing: Over several weeks to months, a global cloud of dust obscures the Sun, cooling the Earth’s surface, effectively eliminating photosynthesis and stabilizing the atmosphere to the degree that the hydrologic cycle is cut off.

The sum of these effects together could kill most flora. The latter results in a large increase in atmospheric CO2, enabling a large warming of the climate in the period after the dust cloud has settled back to Earth

Asteroid impact initializes chain of forcing on climate

This hypothesis is proposed to 65 Million years ago for one possible reason that kills the dinosaurs


External Forcing

Variations in solar output

Orbital variations

Meteors


A meteor is a bright streak of light that appears

briefly in the sky. Observers often call meteors shooting stars or falling stars because they look like stars falling from the sky

Meteor showers – http://www.nasa.gov/worldbook/

meteor_worldbook.html


Solar Variations

Sunspots correlate with solar activityMore sunspots, more solar energy

Sunspots are the most familiar type of solar activity.

THE SOLAR CYCLE

Sunspot numbers increase and decrease – over an 11-year cycle

Observed for centuries. Individual spots last from

a few hours to months. Studies show the Sun is

in fact about – 0.1% brighter when

solar activity is high.


THE MAUNDER MINIMUM

An absence of sunspots was well observed – from 1645 to 1715.

The so-called “Maunder minimum” coincided with a cool climatic period in Europe and North America: – “Little Ice Age”

The Maunder Minimum was not unique. Increased medieval activity

– correlated with climate change.


Little Ice Age

the Little Ice Age to approximately the 16th century to the mid 19th century. It is generally agreed that there were three minima, beginning about 1650, about 1770, and 1850, each separated by slight warming intervals

http://en.wikipedia.org/wiki/Maxima_and_minima


Orbital forcing on climate change

James Croll, 19th century Scottish scientist

Coupled orbital variation and snow-albedo feedback to explain and predict ice age

He suggested that when orbital eccentricity is high, then winters will tend to be colder when earth is farther from the sun in that season. During the periods of high orbital eccentricity, ice ages occur on 22,000 year cycles in each hemisphere, and alternate between southern and northern hemispheres, lasting approximately 10,000 years each.


Further development of orbital forcing by Milutin Milankovitch

Mathematically calculated the timing and influence at different latitudes of changes in orbital eccentricity, precession of the equinoxes, and obliquity of the ecliptic.

Deep Sea sediments in late 1970’s strengthen Milankovitch cycles theory.


Orbital changes

Milankovitch theory:

Serbian astrophysicist in 1920’s who studied effects of solar radiation on the irregularity of ice ages

Variations in the Earth’s orbit– Changes in shape of the earth’s orbit around sun:

Eccentricity (100,000 years)– Wobbling of the earth’s axis of rotation:

Precession (22,000 years)– Changes in the tilt of earth’s axis:

Obliquity (41,000 years)


Earth’s orbit: an ellipse

• Perihelion: place in the orbit closest to the Sun

• Aphelion: place in the orbit farthest from the Sun


Eccentricity: period ~ 100,000 100,000 yearsyears


Precession: period ~ 22,000 years22,000 years


Axis tilt: period ~ 41,000 years41,000 years


Small eccentricity --> 7% energy difference between summer and winter Large eccentricity --> 20% energy difference between summer and winter

Large eccentricity also changes the length of the seasons

Eccentricity affects seasons


Internal Forcing

____________________________

____________________________

Ocean changes Chemical changes in the atmosphere (i.e. CO2)

– Natural variations

Plate tectonics/mountain building

Volcanoes

METR112-Climate Modeling

•Basic concepts of climate system •Numerical method and parameterization in the model•Evaluation and sensitivity study of the model


How can you know the future climate and climate change?


Climate Model NASA Earth Observatory Glossary http://earthobservatory.nasa.gov/Library/glossary.php3?mode=alpha&seg=b&segend=d

A quantitative way of representing the interactions of the atmosphere, oceans, land surface, and ice.

Models can range from relatively simple to quite comprehensive. Also see General Circulation Model.

General Circulation Model (GCM) A global, three-dimensional computer model of the climate system which can be used to simulate human-induced climate change. GCMs are highly complex and they represent the effects of such factors as reflective and absorptive properties of atmospheric water vapor, greenhouse gas concentrations, clouds, annual and daily solar heating, ocean temperatures and ice boundaries. The most recent GCMs include global representations of the atmosphere, oceans, and land surface.

Definition

35 MET 112 Global Climate MET 112 Global Climate ChangeChangehttp://www.usgcrp.gov/usgcrp/images/ocp2003/ocpfy2003-fig3-4.htm

The past, present and future of climate models

During the last 25 years, different components are added to the climate model to better represent our climate system


Ocean: critical roles in climate system

Physical properties and role in climate:

•The biggest water resource on earth

•Low albedo excellent absorber of solar radiation

•One of the primary heat sources for atmosphere

•High heat capacity reduces the magnitude of seasonal cycle of atmosphere

•Important polarward energy transport

•Large reservoir for chemical elements for atmosphere


Ocean: salinity distribution closely relates to precipitation evaporation

From Pickard and Emery: Descriptive Physical Oceanography: An Introduction


Ocean: annual cycle of mixed layer

In winter, SST is low, wind waves are large), mixed layer is deep

In summer, (SST high water stable), mixed layer is shallow.

March is nearly isothermal in upper 100 meters.

March-August, SST increases, (absorption of solar radiation). Mixed layer 30 m.

August-March, net loss of heat, seasonal thermocline eroding due to mixing.


Ocean: surface currents – the gyres

http://www.windows.ucar.edu/tour/link=/earth/Water/images/Surface_currents_jpg_image.html

•Wind drived•Coriolis force and location of land affect current pattern•Clockwise in NH, anticlockwise in SH

The water of the ocean surface moves in a regular pattern called surface ocean currents. The currents are named. In this map, warm currents are shown In red and cold currents are shown in blue.


Surface ocean currents carry heat from place to place in the Earth system. This affects regional climates. The Sun warms water at the equator more than it does at the high latitude polar regions. The heat travels in surface currents to higher latitudes. A current that brings warmth into a high latitude region will make that region’s climate less chilly.

Role of ocean surface currents

http://www.windows.ucar.edu/tour/link=/sun/sun.html

http://www.windows.ucar.edu/tour/link=/earth/polar/polar.html

http://www.windows.ucar.edu/tour/link=/geography/latitude_longitude.html


Graph showing a tropical ocean thermocline (depth vs. temperature). Note the rapid change between 400 and 800 meters.

Thermocline

The thermocline (sometimes metalimnion) is a thin but distinct layer in a large body of fluid (e.g. such as an ocean or lake), in which temperature changes more rapidly with depth than it does in the layers above or below.

In the ocean, the thermocline may be thought of as an invisible blanket which separates the upper mixed layer from the calm deep water below.


Land: where most human impact are applied •Lower boundary of 30% of earth surface lower heat capacity than ocean•Higher variability in interaction with atmosphere than ocean surface

Moisture exchangeAlbedoTopography forced momentum change

•Human impact directly change the land surfaceRelease of CO2 and other GHGsRelease of AerosolChange the Land surface coverUHI effect


The greenhouse gases act as insulation


Land: aerosols

Aerosol: the small particles in the atmosphere which varying in size, chemical composition, temporal and spatial distribution and life timeSource: volcano eruptions, wind lifting of dust, biomass burning, vegetationNew result and great uncertainty of the effect of aerosol on climate

Small aerosol reflect back the solar radiationLarge aerosol can block longwave radiation


General climate model – an approach for the future climate

•Atmospheric GCM is first used in 1950s to predict short-time future weather

•GCM develops and performs continuously improving since then with helps from updating computational resources and better understanding of atmospheric dynamics

•Atmospheric and Oceanic Coupled GCMs (e.g., CCSM, HadCM, GISS, CCCS, CFS) are major ways to predict and project future climate

•A list of GCM and climate modeling programshttp://stommel.tamu.edu/~baum/climate_modeling.html


Regional climate model•The first generation of regional climate model is developed by Dickinson et.al (1989) and Giorgi et. al (1990) due to the coarse resolution of GCM not able to resolve local process•Second generation of RCM (RegCM2) is developed in NCAR (Giorgi et al. 1993) based on MM5 and improved boundary layer parameterizations•Third generation of RCM (RegCM3) (Pal et al. 2007) is developed with various improvements in dynamics and physical parameterizations


Differences between Regional Climate Model (RCM) and Global Climate Model (GCM)

1. Coverage: for selected region, for the globe2. Model resolution: finer resolution, coarse resolution

1 km-10km 60-250km, or larger

3. Model components are different

RCM GCM


Climate Model:

Equations believed to represent the physical, chemical, and biological processes governing the climate system for the scale of interest

It can answer “What If” questionsfor example, what would the climate be if CO2 is doubled?

what would the climate be if Greenland ice is all melt?what………………………..if Amazon forest is gone?what…………………………if SF bay area

population is doubled?


Verify the predictions and statistics of predictions Compatibility with observations Various simulations to assure the agreement with basic theoretical understanding

Model Inter-comparison studies Compare different models

model evaluation-Model uncertainty


MET 112 Global Climate Change -

Climate FeedbacksProfessor Menglin Jin

San Jose State University

Outline Stability/instability Feedbacks Examples Activity


Climate Feedbacks

Earth/Atmosphere is delicate balance – incoming and outgoing radiation

Slight changes in balance can cause – Large changes in global climate

These changes can be enhanced or diminished by positive or negative feedbacks

Positive feedback: – initial change reinforced by another process.

Negative feedback: – initial change counteracted by another process.


Positive Feedbacks

Processes that accelerate a change– Note: Feedbacks cannot initiate change; they

can only alter the pace of change Important examples:

– Ice-albedo feedback– Water-vapor feedback


Stability versus instability

Stable equilibrium Unstable equilibrium

Stable: – Given a perturbation, the system tends to return to original state

Instability: – Given a perturbation, the system moves to another state.


Climate Stability

The Earth’s climate changes as a result of internal/external forcing:– Changes in solar radiation– Changes in the earth’s orbit– Plate tectonics– Volcanoes– Human pollution etc.

These forcings can be thought of as a perturbation (or push) to climate stability.

These changes can be enhanced or diminished by positive or negative feedbacks


Climate Feedbacks

Positive feedback: – initial change reinforced by another process.

Negative feedback: – initial change counteracted by another process.


Positive Feedbacks

Processes that accelerate a change– Note: Feedbacks cannot initiate change; they

can only alter the pace of change Important climate examples:

– Ice-albedo feedback– Water-vapor feedback– Cloud feedback


Ice-Albedo Feedback (Cooling)

Earth Cools

Ice Coverage Increases

Albedo Increases

Absorption of Sunlight Decreases

Initiating Mechanism

Somehow this happens

Pos

itive

Fee

dbac

k


Ice-Albedo Feedback (Warming)

Earth Warms

Ice Coverage Decreases

Albedo Decreases

Absorption of Sunlight Increases


Pos

itive

Fee

dbac

k


Fill in the blanks

1. Increases, increases, increases

2. Increases, decreases, decreases

3. Decreases, increases, increases

4. Decreases, decreases, decreases

Earth Warms

Evaporation

Atmospheric Water Vapor Content

Greenhouse Effect



Water Vapor Feedback (Warming)

Earth Warms

Evaporation Increases

Atmospheric Water Vapor Content Increases

Greenhouse Effect Strengthens


Pos

itive

Fee

dbac

k


Water Vapor Feedback (Cooling)

Earth Cools

Evaporation Decreases

Atmospheric Water Vapor Content Decreases

Greenhouse Effect Weakens


Pos

itive

Fee

dbac

k


Negative Feedbacks

Processes that reduces an imposed change

Important examples:– Cloud feedback– Chemical weathering

Note: Positive/negative feedbacks have no relation to ‘good versus bad’, but are about how a system responds to a change.


Possible Role of Cloud in Warming or Cooling the Atmosphere

Figure 12.7 Role of cloud in both warming and cooling the atmosphere.

Increased warming bytrace gases

(including water vapour)

Increased airtemperatures

Increased watervapour

Increased cloudamount

of terrestrial radiationIncreased trappingIncreased reflection

of solar radiation

War

mingCooling

Net warmingor cooling


Which feedback is positive?

Figure 12.7 Role of cloud in both warming and cooling the atmosphere.

Increased warming bytrace gases

(including water vapour)

Increased airtemperatures

Increased watervapour

Increased cloudamount

of terrestrial radiationIncreased trappingIncreased reflection

of solar radiation

War

mingCooling

Net warmingor cooling

1. Left

2. Right


MET 112 Global Climate Change - Lecture 11

Climate Change: Connections

Menglin JinSan Jose State University

Outline Ozone DepletionOzone Depletion Water - FilmWater - Film PerspectivesPerspectives

Ozone Depletion

TopicsTopics History of Ozone DepletionHistory of Ozone Depletion The Ozone Hole: what, where, why?The Ozone Hole: what, where, why? Ozone into the futureOzone into the future


History of Ozone Depletion: History of Ozone Depletion: connection between human and connection between human and naturenature Chlorofluorocarbons (CFCs) developed in 1940’s and 50’s as:Chlorofluorocarbons (CFCs) developed in 1940’s and 50’s as:

– 1970’s CFCs detected in upper atmosphere.1970’s CFCs detected in upper atmosphere.

– Many of these have long atmospheric lifetimes: Many of these have long atmospheric lifetimes:

– 1974 Rowland and Molina propose that CFC’s can destroy 1974 Rowland and Molina propose that CFC’s can destroy ozone in the stratosphere.ozone in the stratosphere.

– CFC contain chlorine (Cl) CFC contain chlorine (Cl) –

Refrigerants, propellants, fire retardantsRefrigerants, propellants, fire retardants

–(10’s to 100’s of years)(10’s to 100’s of years)

Chlorine can destroy ozone rapidlyChlorine can destroy ozone rapidly


Ozone Hole RecipeOzone Hole Recipe

Ingredients:Ingredients:

Chlorine gasChlorine gas Cold Temperatures (~-80C)Cold Temperatures (~-80C)

Instructions:Instructions:

Allow cold temperatures to form Polar Allow cold temperatures to form Polar Stratospheric Clouds (1-2 weeks).Stratospheric Clouds (1-2 weeks).

Allow time for polar stratospheric clouds Allow time for polar stratospheric clouds to convert chlorine gas into ozone to convert chlorine gas into ozone destroying chemicals. (1 month)destroying chemicals. (1 month)

Bake ingredients with sunlight.Bake ingredients with sunlight.

bingo, a delicious ozone hole!bingo, a delicious ozone hole!

Science interpretationScience interpretation

Chlorine gas is abundant in atmosphere Chlorine gas is abundant in atmosphere due to CFC’sdue to CFC’s

Cold Temperatures (~-80C) only occur Cold Temperatures (~-80C) only occur overover Antarctica Antarctica during the during the cold wintercold winter..

Polar Stratospheric Clouds allow ozone Polar Stratospheric Clouds allow ozone friendly chlorine to be transformed into friendly chlorine to be transformed into ozone destroying chlorine. ozone destroying chlorine.

Ozone depletion then starts when Ozone depletion then starts when sun sun returnsreturns to Antarctica in the spring to Antarctica in the spring

Ozone hole grows from late August Ozone hole grows from late August through till October. through till October.


What is being done about What is being done about ozone depletion?ozone depletion?

Montreal Protocol ~ (1988) international agreement to reduce ozone depleting chemicals

Further amendments accelerated the phase out.

– Developed countries have switched to HCFC’s (more ozone friendly!)

– Developing countries have until 2004/5 to phase out CFC’s.


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 a number of substances believed

to be responsible

for ozone depletion.

The treaty was opened for signature

on September 16, 1987 and entered into force on January 1,

1989 followed by a first meeting in Helsinki, May 1989.

Montreal Protocol

http://en.wikipedia.org/wiki/Treaty

http://en.wikipedia.org/wiki/Ozone_layer

http://en.wikipedia.org/wiki/Ozone_depletion

http://en.wikipedia.org/wiki/September_16

http://en.wikipedia.org/wiki/1987

http://en.wikipedia.org/wiki/January_1

http://en.wikipedia.org/wiki/1989


Is the Montreal Protocol working?

Seems to be!!!

Recent observations indicate that chlorine is beginning to decline in the atmosphere.

Kyoto protocol uses similar approachStart off with small achievable stepsFurther amendments accelerate reductions


Model simulations suggest:– atmospheric chlorine will return to pre-80’s level

__________________ .

– Uncertainties still remain: ____________________ ____________________

In next 50 years or so

Influence of global warming

Phase out of CFC’s

A slow ozone recovery should follow decreasing chlorine concentrations!!!

What are predictions for the future?


What is the connection between ozone depletion and global warming?

No direct connection between these environmental issues.

Global warming produces:

– Tropospheric warming & – Stratospheric cooling

However: Global warming may enhance ozone depletion


What is the connection between ozone depletion and global warming?

An increase in greenhouse gases traps more heat and thus– The stratosphere tends to cool (stratospheric

cooling) Therefore, if the stratosphere cools, then Ozone hole chemistry

– PSCs will likely increase– So slightly more ozone depletion

Global warming will delay recovery of ozone layer


Necessities for lifeNecessities for life

AirAir

WaterWater

FoodFood


Drinkable Water (Freshwater)Drinkable Water (Freshwater)

Of all the water in the world, Of all the water in the world, 97%97% is is sea water (salt)sea water (salt)

Freshwater occupies only Freshwater occupies only 3%3% of the of the Earth’s waterEarth’s water

Of the freshwater, Of the freshwater, 77%77% of freshwater of freshwater is locked up as ice.is locked up as ice.

Water is the most important natural Water is the most important natural resources in the world.resources in the world.


Drinkable Water (Freshwater)Drinkable Water (Freshwater)

The predictions of climate change The predictions of climate change suggest that access to fresh water will suggest that access to fresh water will be made more difficultbe made more difficult– Changes in location Changes in location

and quantity of precipitationand quantity of precipitation– Raising sea levelsRaising sea levels


Economic interestEconomic interest

WaterWater "One of the world's great business "One of the world's great business opportunities. It promises to be to the opportunities. It promises to be to the 21st century what oil was to the 21st century what oil was to the 20th." 20th." - - Fortune MagazineFortune Magazine


Lecture Summary

Ozone depletion is good example of science and policy working together to manage a global environmental concern.

The Ozone hole is produced by unique combination of weather ___________ and chemistry (___________).

The Ozone hole develops during _______ over Antarctica.

Global ozone trends are ___________ except in the tropics,

Global ozone trends are expected to recover in next ___ or more years.

Stratospheric ozone: decreasing, tropospheric ozone increasing


Lecture Summary

Ozone depletion is good example of science and policy working together to manage a global environmental concern.

The Ozone hole is produced by unique combination of weather ___________ and chemistry (___ chlorine ________).

The Ozone hole develops during __ spring _____ over Antarctica.

Global ozone trends are __ negative _________ except in the tropics,

Global ozone trends are expected to recover in next ___ or more years.

cold temps

50

Stratospheric ozone: increasing, tropospheric ozone decreasing


MET 112 Global Climate Change: Lecture 12

Controls on Climate ChangeProfessor Menglin Jin

Outline:Outline: IPCC CA Efforts on Energy Kyoto Treat

The UN Framework Convention on Climate Change

‘stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous

anthropogenic human induced interference with the climate system. Such a level should be achieved within a time-

frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to

proceed in a sustainable manner’


IPCC Assessment ReportIPCC Assessment Report

IPCC-Intergovernmental Panel on Climate Change IPCC-Intergovernmental Panel on Climate Change – Greenhouse gas concentrations continue to rise (warming).Greenhouse gas concentrations continue to rise (warming).– Anthropogenic aerosols tend to produce negative radiative forcing Anthropogenic aerosols tend to produce negative radiative forcing

(cooling)(cooling)““The balance of evidence suggests a discernible human influence The balance of evidence suggests a discernible human influence

on global climate”on global climate”(IPCC) 1997(IPCC) 1997

"There is new and stronger evidence that most of the warming "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human observed over the last 50 years is attributable to human

activitiesactivities .“.“ (IPCC),(IPCC), 20012001

(IPCC) 2007


IPCC Assessment ReportIPCC Assessment Report

IPCC-Intergovernmental Panel on Climate Change IPCC-Intergovernmental Panel on Climate Change – Greenhouse gas concentrations continue to rise (warming).Greenhouse gas concentrations continue to rise (warming).– Anthropogenic aerosols tend to produce negative radiative forcing Anthropogenic aerosols tend to produce negative radiative forcing

(cooling)(cooling)““The balance of evidence suggests a discernible human influence The balance of evidence suggests a discernible human influence

on global climate”on global climate”(IPCC) 1997(IPCC) 1997

"There is new and stronger evidence that most of the warming "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human observed over the last 50 years is attributable to human

activitiesactivities .“.“ (IPCC),(IPCC), 20012001

The IPCC finds that it is “very likely” that emissions of heat-The IPCC finds that it is “very likely” that emissions of heat-trapping gases from human activities have caused “most of the trapping gases from human activities have caused “most of the observed increase in globally averaged temperatures since the observed increase in globally averaged temperatures since the

mid-20th century.mid-20th century.(IPCC) 2007


The IPCC finds that it is “very likely” that emissions of heat-trapping gases from human activities have caused “most of the observed increase in globally averaged temperatures sincethe mid-20th century.”

Human Responsibility forClimate Change

Source: IPCC Climate Change 2007: The Physical Science Basis—Summary for Policymakers.


Emission Scenarios

SRES (special report on emission scenarios)


Scenarios


CO2 concentrations (amount)


Future Predictions: Temperature


Notes on Temperature Projections

Projected Warming: 2000 – 2100 ranges from ~1.4°C to ~5.8°C.

Curves represent warming produced for seven scenarios by a model with average sensitivity.

Each bar on right represent range of warming produced – by models of differing sensitivies for a

specific scenario.


Land areas are projected to warm more than the oceans with the greatest warming at high latitudes

Annual mean temperature change, 2071 to 2100 relative to 1990: Global Average in 2085 = 3.1oC


Some areas are projected to become wetter, others drier with an overall increase projected

Annual mean precipitation change: 2071 to 2100 Relative to 1990


Sea Level


Sea Level Rise

Annual mean precipitation change: 2071 to 2100 Relative to 1990


1. What percentage of electricity generation comes from the burning of natural gas?

2. What percentage of transportation energy comes from natural gas burning?

3. What percentage of transportation energy use comes from coal?

4. If you buy an electric car, what is the mostly likely source of energy?

5. Where does most residential energy come from?

Questions


Mitigation of climate changeMitigation of climate change

Mitigation: Mitigation: – Steps taken to avoid or minimize negative Steps taken to avoid or minimize negative

environmental impacts. environmental impacts.

Mitigation can includeMitigation can include: : • avoiding the impact by not taking a certain action;avoiding the impact by not taking a certain action;

• minimizing impacts by limiting the degree or minimizing impacts by limiting the degree or magnitude of the action; magnitude of the action;

• rectifying the impact by repairing or rectifying the impact by repairing or restoring the affected environmentrestoring the affected environment


The Kyoto Protocol is an international agreement linked to The Kyoto Protocol is an international agreement linked to the United Nations Framework Convention on Climate Change. the United Nations Framework Convention on Climate Change. The major feature of the Kyoto Protocol is that it sets binding The major feature of the Kyoto Protocol is that it sets binding targets for 37 industrialized countries and the European communitytargets for 37 industrialized countries and the European community for reducing greenhouse gas (GHG) emissions.for reducing greenhouse gas (GHG) emissions.These amount to an average of five per cent against 1990 levelsThese amount to an average of five per cent against 1990 levels over the five-year period 2008-2012. over the five-year period 2008-2012.

The Kyoto Protocol was adopted The Kyoto Protocol was adopted in Kyoto, Japan, in Kyoto, Japan, on 11 December 1997 andon 11 December 1997 and entered into force on entered into force on 16 February 2005 16 February 2005


The Kyoto ProtocolThe Kyoto Protocol A United Nations sponsored effort:A United Nations sponsored effort:

– Calls for Calls for reductionsreductions of greenhouse gas emissions by of greenhouse gas emissions by industrialized countriesindustrialized countries of of 5.2 per cent below 1990 levels5.2 per cent below 1990 levels. .

– The Protocol will go into force after The Protocol will go into force after 1.1. The protocol has been ratified by a minimum of 55 countries.The protocol has been ratified by a minimum of 55 countries.2.2. The ratifying nations comprise 55% of global greenhouse The ratifying nations comprise 55% of global greenhouse

gas emissions.gas emissions.– Current status:Current status:

156 countries have signed accounting for 61% of global CO156 countries have signed accounting for 61% of global CO22.. US not planning on signing protocol (US accounts for 36% of US not planning on signing protocol (US accounts for 36% of

COCO22 emitted) emitted) Kyoto protocol went into force in Feb 2005Kyoto protocol went into force in Feb 2005


Kyoto TargetsKyoto Targets

Industrialized countries will reduce their collective emissions by 5.2% compared to the year 1990

Note that compared to the emissions levels by 2010 without the Protocol, this target represents ~30% cut).

Calculated as an average – over the five-year period of 2008-12.

Target includes six greenhouse gases - carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, HFCs, and PFCs

http://en.wikipedia.org/wiki/Carbon_dioxide

http://en.wikipedia.org/wiki/Methane

http://en.wikipedia.org/wiki/Nitrous_oxide

http://en.wikipedia.org/wiki/Sulfur_hexafluoride

http://en.wikipedia.org/wiki/Hydrofluorocarbon

http://en.wikipedia.org/wiki/Perfluorocarbon


Kyoto TargetsKyoto Targets

National targets– European Union - 8% below 1990 levels– USA - 7% below 1990– Japan - 6% below 1990– Russia 0% (stay at 1990 levels)– Australia 8% over 1990 levels) – Developing countries (no target)

China, India etc.


Kyoto Targets: Developing Kyoto Targets: Developing countriescountries

The UN Framework on Climate has agreed:

1. The largest share of historical and current global emissions of greenhouse gases – has originated in developed countries;

2. Per capita emissions in developing countries – are still relatively low;

3. The share of global emissions originating in developing countries – will grow to meet their social and development needs.


The Kyoto Mechanisms

Under the Treaty, countries must meet their targets primarily through national measures. However, the Kyoto Protocol offers them an additional means of meeting their targets by way of three market-based mechanisms.

The Kyoto mechanisms are: Emissions trading – known as “the carbon market" Clean development mechanism (CDM) Joint implementation (JI).

http://unfccc.int/kyoto_protocol/mechanisms/items/1673.php

http://unfccc.int/kyoto_protocol/mechanisms/emissions_trading/items/2731.php

http://unfccc.int/kyoto_protocol/mechanisms/clean_development_mechanism/items/2718.php

http://unfccc.int/kyoto_protocol/mechanisms/joint_implementation/items/1674.php


Kyoto Protocol MechanismsKyoto Protocol Mechanisms

Keep to assigned amounts of GHG with overall worldwide reduction by at least 5% below 1990 levels by 2008-2012

Countries can meet their commitments together

Joint implementation -Countries can work together to meet their emission reduction targets.

Richer (annex 1) countries can help developing countries to achieve sustainable development and limit GHG increases and then claim some emission reductions for their own targets

Emissions trading - countries can trade in ‘emission units’


Emissions TradingEmissions Trading

Each country has an emission limit. If this country cannot meet it’s target, it may

purchase carbon credits from other countries (on the open market) who are under their limit.

This financially rewards countries that meet their targets.

Countries also receive carbon credits through

– –


Emissions TradingEmissions Trading

Each country has an emission limit. If this country cannot meet it’s target, it may

purchase carbon credits from other countries (on the open market) who are under their limit.

This financially rewards countries that meet their targets.

Countries also receive carbon credits through – clean energy programs (i.e. greentags) – carbon dioxide sinks (i.e. forests, oceans)


Class Participation

By 2050, which city has the longest heat wave days? Why?

What are the differences between the low emission and high emission cases in terms of heat wave days by 2090 for city Riverside? How about city LA?

How many people may die due to heat wave in SF in 2050 and 2090?

Your name_________Your name_________

metr112 global climate change professor menglin jin san jose state university december 1, 2008

Documents

global climate change

global climate change

climate polarward

agent of change

o18 proxy o18

temperature change features

global models

c14 c14