METR 112 Global Climate Change Professor Menglin Susan Jin San Jose State University, Dept of Meteorology and Climate Science

Outline of today’s lecture 1.Introduction and Welcome 2.Discussion on the “greensheet” 3.Learning Contract 4.First glance on observations of Changing Climate

For greensheet, class ppt notes NOT any other websites!

About Professor to be an effective teacher 3. A very good scholar Research projects: funded by NASA, NSF, Department of Defense On land surface climate change, urbanization, remote sensing 20 leading author papers on top journals

Goal METR112 will help you to know the fundamentals of global climate system, climate change, and gain appreciation of the complexities involved with climate change issues

Homework: 20% Midterm Exam: 20% Class Participation 5% Group Project: 20% Final Exam: 35% Scale: 90+ A, 80’s B, 70’s C, 60’s D, <60 F Homework will be assigned on Tuesdays in class collected in discussions on two weeks later.

Content 1. Knowledge on Climate System: Atmosphere Structure Land Surface Properties Land-Ocean-Atmosphere Interaction Global Energy Balance Global Hydrological Cycle C cycle Glacier Aerosols and clouds Ozone 2. Past Climate Change 3. Recent Climate Change 4. Climate Modeling – Its basics and Uncertainty 5. Climate Feedback 6. Urban Climate Change – Land Cover Change 7. Climate Change and Human Health 8. Remaining Questions on Global Climate Change Research Things You can do to Fight Climate Change

Lecture Hour: TTH session 10:30 – 11:15 AM Place: DH515 Office Hour: 1 PM ‐ 2:30 PM, Wednesday 9:50 -10:20 AM, Tuesday more (TA) Place: MSJ’s Office (DH613) TA: Terrence Mullens TA’s "Terrence TA’s office: DH619 METR112 I will meet with you for extra office hour whenever you need. send for appointment. I am approachable!!!

References (not a text book): Useful materials will be assigned on webpage/homework/class (cheap!) “Understanding Weather & Climate” by Edward Aguado and James E. Burt (Third Edition) Video collections:

Learning Contract Instructor –On time and prepared. –Answers questions. –Approachable and friendly. –Fair with assignments and grades. –Genuinely concerned about your learning and intellectual development.

Learning Contract Students –Make every effort to arrive on time; and if late, enter class quietly. – Preserve a good classroom learning environment by a) refraining from talking when other people are talking b) turning off cell phones. –Be courteous to other students and the instructor. –Aware that learning is primarily their responsibility. –Aware of universities policy on academic integrity and pledge to abide by them at all times. –Have read and understand what plagiarism is and know how to cite sources properly.

Academic Integrity Integrity of university, its courses and degrees relies on academic standards. Cheating: –Copying from another’s test, cheatsheet etc. –Sitting an exam by, or as, a surrogate. –Submitting work for another Plagiarism: –Representing the work of another as one’s own (without giving appropriate credit)

Plagiarism Judicial Affairs Look at the Student Code of Conduct Read through SJSU library site on Plagiarism

GreenSheet (see handout) Homework online turnin (D2L) Class Participation Research Project Final grade

Let’s see some key global change observations…...

Change in surface temperature in 20 th century

Two main points in this figure Global mean surface temperatures have increased °C since the late 19th century The 20th century's 10 warmest years all occurred in the last 15 years of the century Note: 1. why is global mean? 2. what is surface air temperature? (see next few slides)

Temperature is measured by therometer Thermoeter is required by WMO (see next slide)

World Meteorological Organization (WMO) Weather station

Observed temperature changes Cooling due to Mt. Pinatubo Warming due to El Niño Cooling due to La Niño

Such an increase continues. The best scientific estimate is that global mean temperature will increase between 1.4 and 5.8 degrees C over the next century as a result of increases in atmospheric CO 2 and other greenhouse gases. This kind of increase in global temperature would cause significant rise in average sea-level ( meters), and other severe consequences Mean increase means that many regions increases much higher, and these regions have problems in terms of extreme heat, drought, flood. Global mean surface temperatures have increased °C since the late 19th century The 20th century's 10 warmest years all occurred in the last 15 years of the century Why does this matter? (important!)

The Land and Oceans have both warmed, but…

Important point of this slide Although global mean surface has been warming up, for each region the change can be different! (can be no change, warming, or cooling) Class activity: find out your grandpa’s hometown and see how the temperature is changed there?

Antarctic Ice Shelves Most common Ice Shelf: Giant floating platform of ice formed from glaciers located along coastlines meters thick Can last for thousands of years 10 major ice shelves in Antarctica

Larsen Ice Shelf Break

Then and Now Temperature rises have also led to the expansion of species ranges in Antarctica. “Long term monitoring of continental Antarctic terrestrial vegetation is crucial for accurate measurement and predictions of vegetation dynamics in response to future temperature regimes around the world”

The “Keeling curve,” a long-term record of atmospheric CO2 concentration measured at the Mauna Loa Observatory (Keeling et al.). Although the annual oscillations represent natural, seasonal variations, the long-term increase means that concentrations are higher than they have been in 400,000 years. Graphic courtesy of NASA’s Earth Observatory.

Still going up!

CO 2 Unit atmospheric concentrations of CO2 in units of parts per million by volume (ppmv). Each ppmv represents 2.13 X10 15 grams, or 2.13 petagrams of carbon (PgC) in the atmosphere Atmospheric CO2 concentrations rose from 288 ppmv in 1850 to ppmv in 2000,288 ppmv in ppmv in 2000 for an increase of 81.5 ppmv, or 174 PgC. In other words, about 40% (174/441.5) of the additional carbon has remained in the atmosphere, while the remaining 60% has been transferred to the oceans and terrestrial biosphere.

Atmosphere Composition and Structure

Vertical Layers of the Lower Atmosphere

Atmospheric Properties vs. Altitude

Table 1: Composition of the Atmosphere Gas Percentage by Volume Nitrogen78.08 Oxygen Argon 0.93 Trace Gases Carbon dioxide Methane Ozone Chlorofluorocarbons Water vaporHighly variable (0-4%)

The early Greeks considered "air" to be one of four elementary substances; along with earth, fire, and water, air was viewed as a fundamental component of the universe. By the early 1800s, however, scientists such as John Dalton recognizedJohn Dalton that the atmosphere was in fact composed of several chemically distinct gases, which he was able to separate and determine the relative amounts of within the lower atmosphere. He was easily able to discern the major components of the atmosphere: nitrogen, oxygen, and a small amount of something incombustible, later shown to be argon. The development of the spectrometer in the 1920sspectrometer allowed scientists to find gases that existed in much smaller concentrations in the atmosphere, such as ozone and carbon dioxide. The concentrations of these gases, while small, varied widely from place to place. In fact, atmospheric gases are often divided up into the major, constant components and the highly variable components, as listed below:

Although both nitrogen and oxygen are essential to human life on the planet, they have little effect on weather and other atmospheric processes. The variable components, which make up far less than 1 percent of the atmosphere, have a much greater influence on both short-term weather and long-term climate. For example, variations in water vapor in the atmosphere are familiar to us as relative humidity. Water vapor (H 2 O), CO 2, CH 4, N 2 O, and SO 2 all have an important property: they absorb heat emitted by the earth and thus warm the atmosphere,heat creating what we call the "greenhouse effect." Without these so-called greenhouse gases, the surface of the earth would be about 30 degrees Celsius cooler - too cold for life to exist as we know it. Global warming, on the other hand, is a separate process that can be caused by increased amounts of greenhouse gases in the atmosphere.

The Greenhouse Effect (Important concept)

Greenhouse gases (important!) CO 2 CH 4 N 2 O (Nitrous Oxiode, so called “laughing gas”) CFC O 3 H 2 O by the early 21st century, N 2 O had become nearly as important a greenhouse gas as methane. Their best guess was 0.7°C for N 2 O, and 0.3°C for methane. Wang et al. (1976).Wang et al. (1976)

atmosphere is not uniform temperature decreased with altitude division of the atmosphere into layers based on their thermal properties. Troposphere: surface to12~18Km all weather occurs temperature decreases with -6.5° C/kilometer (average!) Stratosphere: 18-50km temperature increase due to ultraviolet (UV) absorption by Ozone (O 3 ) Thermosphere The outermost layer of the atmosphere, where gas molecules split apart into ions. Mesosphere 50-80km

Vertical Layers of the Lower Atmosphere

Greenhouse Gases are here

Greenhouse Gases Carbon Dioxide Methane Nitrous Oxide CFCs (Chlorofluorocarbons) Others Water vapor is one greenhouse house gas (GHG) In fact, it is the most abundant GHG

Methane

Anthropogenic Methane Sources Leakage from natural gas pipelines and coal mines Emissions from cattle Emissions from rice paddies

Nitrous Oxide N 2 O

Anthropogenic Sources of Nitrous Oxide Agriculture Bacteria in Soils Nitrogen fertilizers

CFCs (Chlorofluorocarbons) CFC-11 CFC-12

Sources of CFCs Leakage from old air conditioners and refrigerators Production of CFCs was banned in 1987 because of stratospheric ozone destruction –CFC concentrations appear to now be decreasing –There are no natural sources of CFCs

One World

World Population 6,446,131,400 Human activities change environment

Class Participation Name_________ 1.Can you understand today class? 2. What is the surface temperature change from 1990 – 2000? 3. How did you know of this class?