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Announcements
National Residence Hall Honorary (NRHH) Pie Day When: Thursday, April 22nd from 11:30 AM – 1 PM
Where: Outside the library
Price: $5 per throw and $10 per shove (just for reference, the prices for the members of NRHH to get pied are: $2 per throw and $5 per shove)
April 19Alternative
Energy
April 21Global Warming
April 26Student Talks
April 28Student Talks
May 3Student Talks
May 5Student Talks
Physics 6 Schedule
“Is the human race like the bucket of frogs about to be boiled, led and bossed by happy frogs who don't know they're in the same bucket?”—culturechange.org
Your Talks
April 26 (6 students)Lisa Hassler & Suzanne SimpsonFrank Keehn & David SaundersCourtney PittsDarryl Coleman
The class period is 75 minutes (4:00-5:15). You are allotted 10 minutes if presenting alone, 15 minutes if two are presenting, 20 minutes if three are presenting. If talks end early, I may lecture.
April 28 (8 Students)Christina WilsonKelsey Hansen, Andrew Lott, and Elizabeth RusinkoSara MitchellMelony MeierAlexandra McCormick & Ally Nissen
Your Talks
The class period is 75 minutes (4:00-5:15). You are allotted 10 minutes if presenting alone, 15 minutes if two are presenting, 20 minutes if three are presenting. If talks end early, I may lecture.
May 3 (4 students)Sarah GrantFareedah WashingtonDanielle WarcholDebra Wielms
May 5 (5 students)Jazmine BellD Naya MimsDrew Skyles & Zach HumphreyJosh Smith
Grading Your Talks
Tentative grading sheet:
environment-related topic (0-3)scientific evidence presented (0-5)effort by presenter to evaluate evidence (0-4)talk organized and flowed logically (0-5)evidence of thought on part of presenter (0-5)good effort and enthusiasm (0-3)
total (0-25)
You may use the computer and projector for your talk. Here are some options:
Bring your talk on a CD or flash drive and hope it works! No floppies! (Computer doesn’t have a floppy drive.) E-mail your talk to me before noon on the day you are talking (but earlier is better). I’ll put it a flash drive and on the network. I might even get time to test it.
If your talk includes any video files, you need to make sure they are provided and work (classroom computer may not be able to play all media files).
As a backup, e-mail your talk to yourself, so you have access to it if your flash drive or CD is bad.
Remember:
The fact that it works on your computer doesn’t guarantee it will work on the classroom computer.
If it’s important, have backups. At least two, besides the original.
(Sooner or later, if you don’t make backups, you will suffer pain. Major pain.)
Untested technology is guaranteed to fail if you don’t have a backup plan.
Take exit 214 (Leasburg exit).
Onondaga Cave
Go south on Route H for 7 miles.
Go through Leasburg to get to Onondaga Cave State Park.The paved road ends just before you get to the visitor center.
28 miles from exit 186 to exit 214, 7 miles to park. Julia (an ex-student who worked there) said 35 minutes. Park web site says 45 minutes from Rolla.
If you cross the Meramec river, you’ve gone too far!
Global Warming
Sources of Information
Information is not really so neatly packaged as I will make it sound here… but there seems to be 3 “types” of sources of information on global warming.
Global Warming
2010 Update
What follows is my 2008 lecture. The whole global warming debate has become disgustingly (my opinion) politicized. I can’t even teach this course without having other faculty lobbying me to include their beliefs in the course.
Source of Information I
Government agencies such DOE (Department of Energy), EPA, NOAA, USGS, NASA (look under “climate change”).They tend to emphasize facts and present information (sometimes too much!). They will mention areas of speculation without drawing conclusions.
Environmentalist organizations.
Web site examples:http://globalwarming.enviroweb.orgNatural Resources Defense Council
You will find lots of valuable information on these sites.You will also find lots speculative information expressed as if it were fact.Why are they expressing speculation as if it were fact?Opinion: they believe their speculation represents the truth. They know it takes a major emergency to wake up a democratic society. They want to wake people up “before it’s too late.”
Source of Information II
Global warming skeptics.
Web site examples:http://www.skepticism.net/faq/environment/global_warming/ www.globalwarming.org Global warming skeptics, for a variety of reasons, don’t want government involved in business or personal matters.
Source of Information III
Oregon Institute of Science and Medicine.
Claim to have signatures of 19,000 of scientists on “global warming is good” petition. Small fraction of signees seem to actually be scientists of any discipline (perhaps 2500). I am afraid to contact them and ask for a list of names.
Pro-global warming article published in Journal of American Physicians and Surgeons.
This journal seems to be more about politics than medicine.
The institute has only one paid staff member. Two of the 8 people they list as “faculty” have been dead for some time.
Intergovernmental Panel on Climate Change
Web site: http://www.ipcc.ch/index.htm
Source of Information IV
I’ll refer to the 2007 IPCC report on climate change a number of times during this lecture.
The IPCC report is a combined effort of scientists and diplomats from 120 countries.
The diplomats have the final say (excerpts from an AP article)…
An authoritative international global warming conference, already past its deadline for finishing a comprehensive report, lapsed into an unprecedented showdown between scientists and diplomats over authors' concerns that governments were watering down their warnings.
The paragraph originally said scientists had "very high confidence" — which means more than 90 percent chance of accuracy — in the statement that many natural systems around the globe "are being affected by regional climate changes, particularly temperature increases."
A dramatic dispute between the scientific authors of the report and its diplomatic editors erupted over a paragraph in the 21-page summary regarding how much confidence the scientists have in their findings…
After days of intensive small group negotiations over this section, delegates from China and Saudi Arabia on Friday insisted that the confidence be reduced to "high confidence" which means more than 80 percent accuracy. Source: AP news article. Here is one link. You might be justified in being skeptical about a web site called “Climate Ark,” but the news article is not theirs.
Unfortunately, global warming has turned into a political debate between conservatives and moderates.*
*Opinion: there are no liberals left in this country. Well, not enough to be worth counting.
Debates about science settle nothing. A theory works or it doesn’t. Nature doesn’t care** about your opinion. Nature doesn’t care about how good you are at convincing other people you are right.
**Of course, “nature,” being inanimate, doesn’t “care” about anything.
What do you do if a theory is inconclusive? Discuss, argue, experiment, revise your theory, experiment some more. Debate is for the Debate Team.
A personal note.
I am OK with you voicing your opinion.
I am very disturbed if you attempt to conceal your motives behind a name.
I am OK if you disagree with me.
I am not OK if you want to force me to take action based on your opinion alone.
I find it’s easy to tell when you’re dealing with an “environmentalist.” The skeptics may let you know who they are, but you may have to do a lot of digging. Some are dishonest.
Watch for inflammatory uses of words. “Global warming handwringers...” If you have to make a point by name calling, I question whether you have a point.
www.globalwarming.org seems to be run by an organization called the “National Consumer Coalition.” They believe in a free market economy. Government has no business getting involved.
Opinion: the skeptics tend to argue by tearing down, focusing on areas of disagreement and dispute and claiming these areas are “proof” that global warming is not real, when in fact, they are only proof that science is being done.
The trouble is, I can’t tell if the “National Consumer Coalition” is really a coalition of consumers.
There’s even an annual “World Naked Bike Ride Day*” to protest! If you can’t make a point with your clothes on, does taking them off make your argument stronger?
I should give equal treatment to the environmentalists, shouldn’t I?
“Now that we know of massive species extinction and a North Atlantic ice age right up ahead, the question for any concerned citizen: Is the human race like the bucket of frogs about to be boiled, led and bossed by happy frogs who don't know they're in the same bucket? We have met the enemy and he is us. Stop the global warmers!” http://www.culturechange.org/
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*I used to have a link to their web site. Decided to remove it. It doesn’t offend me, but might get me in trouble. Google if you have to.
http://www.skepticism.net–this is tricky!
I would like to encourage informed skepticism. I am disturbed by skepticism based on personal biases.
The site is not very active these days. On January 7, 2004, were 10 headlines on the site.
I saw 4 headlines and I said Yes! Yes! Yes!
I saw a headline and I said No! No! No!
I saw 5 headlines and I said Maybe! Maybe! Maybe! (Need to read what he is REALLY saying.)
The web page author is “a pro-gun, anti-campaign finance reform libertarian.” Up-front about it (if you dig a bit).
Why all this time spent on the Who’s Who of the global warming debate?
“I don’t believe in conspiracy theories. ‘Never attribute to conspiracy what can be explained by human stupidity.’ Nevertheless, you can’t be too paranoid these days.”—me
Global Warming: A Definition
Do you think it would be a good idea to know just what the discussion is about?
How about this for a definition:
“Global warming is the warming of the earth due to the influence of humans, with a focus on warming due to emission of greenhouse gases.”
What Do We Know?
Without the greenhouse effect, we wouldn’t be alive.
So what is the greenhouse effect?
1. The Planetary Greenhouse Effect
No, no, no. Not that one. This one:
typo?
Actually, that picture contains at least one common error. This one, from USA Today, is better (in science content):
I don’t want to nitpick. If you want to say this: “the greenhouse effect is caused when gases in the atmosphere behave as a blanket and trap radiation which is then reradiated to the Earth,” I won’t stop you. But please visit the bad greenhouse page to see why the sentence is wrong.Also, a real greenhouse (or car in the sun) gets hot because heated air is trapped inside it. Not so with the atmosphere.
Anyway, without this “planetary greenhouse effect,” the earth’s average temperature would be about -18 C (a bit below 0 F) instead of about 16 C (about 60 F).
This is correct: “The surface of the Earth is warmer than it would be in the absence of an atmosphere because it receives energy from two sources: the Sun and the atmosphere.”
The planets give us some idea of the effect of the earth’s atmosphere on it’s temperature. You can go to planetscapes and look up planet distances from the sun, and get an estimate of the average temperature of each planet (and our moon).
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Let’s focus on the planets out to Jupiter (plus our moon).
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I’ll discuss this in class!
I’m getting many of these nice images from GRID Arendal, an environmental information center in Arendal, Norway.Do you trust Norwegians?
GRID Arendal was established by the Government of Norway and the United Nations Environment Programme.Do you trust the United Nations?
Do you trust anybody who spells Program “Programme?”You can read GRID Arendal’s statement of values here.
There was a paper published in 2005 that claims there is no such thing as a greenhouse effect.
I have not seen that claim accepted by the physics community.
If you’re keeping score, the planetary greenhouse effect is real and significant. Probably.
Score:Global Warming Handwringers 0.9Boss Frogs in our Bucket 0.1
2. Evidence of Past Climate Changes
If we see our climate changing now, maybe we should see what it has done in the past.
Much of the following material came from http://globalwarming.enviroweb.org/. The site’s use of frames makes it difficult to give a link for each quote.
More recent, detailed, and thoroughly-documented information is available here: http://www.ipcc.ch/ipccreports/ar4-wg1.htm (see Chapter 6)
I’ll do my best to limit the discussion here to topics outside the global warming political debate.
“Seventy-five million years ago, the Earth's average temperature was about 10°F (5.6°C) higher than it is today. Almost everywhere the climate was warm and humid.”How do we know that? Fossils of warm-weather plants and animals living in places where it’s too cold for them now.
OK, we don’t “know” that, we “infer” that.
In that sense, we don’t “know” a lot about the past other than through eyewitness reports.In that sense, we don’t “know” a lot about the past other than through eyewitness reports. And eyewitnesses have been shown to be the least reliable of all witnesses.
fossils of warm-water sea creatures, found in South
Dakota
It is inferred that the greater temperature was due to atmospheric CO2 from volcanic eruptions, and to the fact that less of the land was above water, so that there were fewer plants to take in CO2 from the atmosphere.20,000 years ago, ice covered 1/3 of the earth’s land area, up to two miles thick in places, and the earth was about 9°F (5°C) colder than it is now.
How do we know? Fossils of cold-weather creatures in currently-warm places. We saw other evidence of the glaciers in the first video this semester.
Other clues about climate in the past: ice cores, tree rings, stalagmites, sediments that settled on ocean floors.
Most of us think of the “Ice Age” as being the last time glaciers advanced on us from the north, which reached a peak about 20,000 years ago.
Actually, the geological record shows evidence for repeated Ice Ages, lasting millions of years each. The current Ice Age is a couple of million years old. The glacier advance 20,000 years ago was just one episode of glacier advance during the current Ice Age.
Possible reasons for cooling: fewer volcanoes, more land area covered by plants absorbing CO2, more land area near the North Pole.
That’s all I want to discuss about past climate changes right now. Here are the points I wanted to make...
…and there have been huge climate changes in the past, without any humans around to cause them ...Humans have been lucky to live during a period when the earth’s temperature is moderate and its climate stable…
…and the temperature changes are correlated with the atmosphere’s CO2 content.
10°F warmer and Canada is a tropical jungle.
9°F cooler and Illinois is buried under 2 miles of ice.
A “little” temperature change makes a big difference!
http://www.ipcc.ch/ipccreports/ar4-wg1.htm, chapter 6, page 444
This is ammunition for both sides of the political debate:Humans are not affecting climate: if past climate changes happened without human intervention, why should the present be any different? Plus, skeptics say the increased temperatures caused increasing CO2, and not the other way (so what caused the increasing temperatures?).Humans are affecting climate: if past climate changes are related to atmospheric CO2, and humans are putting CO2 in the atmosphere, why should we not expect a change?Score after the 2nd round:
Global Warming Handwringers 1½ Boss Frogs in our Bucket ½
Final note: you don’t have to believe any of this climate change stuff if you don’t want to.
If you choose not to believe it, you may not use it in any of your arguments, either for global warming or against global warming.
3. Greenhouse Gases
The claim is that CO2 generated by humans is—or might be—enhancing the planetary greenhouse effect.
Let’s see how that works. Or go to slide 46 if time is short.Every object that has a finite (non-zero) temperature emits radiation. That radiation can be modeled by something called a “blackbody”—a perfect absorber and emitter of radiation.
“Blackbody” is not a politically incorrect term that physicists have neglected to abandon. It is appropriate because objects at “normal” temperatures emit this radiation at wavelengths not visible to the human eye.
Right now I am emitting and reflecting radiation. You see me because of the reflected radiation (light). You cannot see the radiation I am emitting unless you wear night vision goggles.
The spectrum of blackbody radiation can be calculated easily using simple quantum mechanics.
It is also easy to make a quite good “blackbody” in the laboratory; the theoretical and experimental spectra agree quite nicely.
Here are blackbody spectra for an object at 37°C (about the temperature of your skin) and 100°C (boiling water).
All the radiation is in the infrared (invisible, hence “black”).
Above is the spectrum of blackbody radiation from an object at a temperature of 6000 K—about the surface temperature of the sun.
If you are on-line, click here for an applet: you control the thermometer and view the resulting spectrum.
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Here’s a measured solar spectrum. It is not smooth like a blackbody radiation curve because there are other mechanisms for radiation of energy from the sun.
However, the overall shape is described well by a blackbody spectrum.
“So what does this have to do with global warming?
Good question. Notice how the amount of energy radiated depends very strongly on the temperature of the object.
The atmosphere radiates energy!
Let’s start off with a cold earth with no atmposphere and “turn on” the sun.
A cold earth radiates no energy.
As heat from the sun increases the earth’s temperature, it begins to radiate energy (in all directions, of course). The earth will continue to warm up until it reaches a “steady-state” condition, where the amount of energy in equals the amount of energy out.
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Now add an atmosphere
Some of the energy from the atmosphere reaches the earth.
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Now add an atmosphere. The atmosphere absorbs some of the earth’s energy, warms up, and radiates energy in all directions.
The earth warms up…
…radiates more energy…
And eventually reaches a steady-state condition, but at a higher temperature.
“So what does this have to do with CO2?
Good question.
Remember the atmosphere?
What’s in it?
Duh. You’re showing me what’s in it. Lots of O2 and N2. A little bit of CO2 and H2O.
Each of these compounds, O2, N2, CO2, H2O, and the rest, has a different chemical composition, with different bonds and different rotational and vibrational energy modes.*
*A couple of fancy terms, intended to convey the idea that there is some physics behind all this, and to show how you can sound like an expert without actually conveying any information to your audience.
Each of these compounds, O2, N2, CO2, H2O, and the rest, is particularly good at absorbing its own “preferred” thermal energy.
Here’s what I mean by that...
CO2, because of its molecular structure, “likes” to absorb radiant energies of these wavelengths.
Water vapor and ozone also have their “favorite” wavelengths.
Notice that CO2 is “good” at absorbing a large part of the energy the earth is trying to radiate away.
The same goes for water vapor and ozone.
Oxygen and nitrogen absorb at other wavelengths, which don’t represent a significant proportion of the earth’s radiant energy.
If CO2 absorbs this energy, what is it going to do later?
Get rid of it. Radiate “extra” energy. Some of it goes back to earth. A larger energy output from the atmosphere means a higher temperature on earth.
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“Greenhouse gas energy.”
Temperature goes up!
Problems with this graphic: it says “blankets and windows.” I am OK if you want to think in those terms. But see bad greenhouse for the technically correct way of looking at this.
We have seen a mechanism by which CO2, and other greenhouse gases, can increase the earth’s temperature.
However, CO2 and Methane were entering and leaving the atmosphere long before there were humans around.
Score after the 3rd round:Global Warming Handwringers 2 Boss Frogs in our Bucket 1
Points go to the Handwringers.
Points go to the Boss Frogs.
The referee awards ½ point to each side.
4. Evidence of Human Influence on the Atmosphere
The famous Mauna Loa CO2 data:
There are lots of other places to find this figure, although the graphics are generally not as “pretty,” For example, see the Carbon Dioxide Information Analysis Center at Oak Ridge National Laboratory.
The Mauna Loa data is significant because it represents the longest continual monitoring of atmospheric CO2……and the rate of increase of atmospheric CO2 at Mauna Loa correlates with the amount of CO2 we are putting in the atmosphere.
What would the Boss Frogs say?
“You haven’t proved the excess Mauna Loa CO2 was produced by humans.”
http://www.ipcc.ch/ipccreports/ar4-wg1.htm, chapter 2, page 138
“You haven’t proved the excess Mauna Loa CO2 was produced by humans.”
In a criminal trial, where proof is required “beyond any reasonable doubt,” I am willing to wait for more evidence.In a civil trial, where proof is required that seems “more reasonable than not,” I disagree.
Score after the 4th round:Global Warming Handwringers 3 Boss Frogs in our Bucket 1
The referee awards 1 point to the Handwringers.
So what should we do?
Hold on a minute. Let’s not get carried away just yet.
“If you want me to believe it is happening, you have to do the following:”
“Global warming is the warming of the earth due to the influence of humans, with a focus on warming due to emission of greenhouse gases.”
Give evidence that something is happening (an “effect”).Demonstrate a cause (or mechanism) for the effect.
Show a connection between the cause and the effect.You have to eliminate other possible causes.
You have to provide other evidence that supports your theory.
Demonstrate a cause (or mechanism) for the effect. Show a connection between the cause and the effect.
5. Evidence for Warming
I’m not presenting this “logically,” which would be to first claim that the earth is warming, and then present evidence.I’ve been presenting things that are “known” first.
So is the earth actually warming?
From the Global Change Research Information Office (a Federal agency):
1997: “for the Northern Hemisphere and for the globe, 1995 was the warmest year of the record, and proxy indicators such as tree rings suggest this century is the warmest since at least 1400 AD.”
Is something happening? Are there any questions you should ask?
How do you measure “global average temperature?”
Can you even measure—with any confidence that your measurements have meaning—the average temperature of any place on earth?
Say you have a temperature station just south of Rolla. Suppose it’s in an open field surrounded by woods.
What if somebody chops down all the trees?
What if somebody replaces the woods with an apartment complex?
What if Rolla turns in to a city of 500,000 population?
These are good points the Boss Frogs bring up.
But if you’ve ever investigated how the weather service (for example) measures temperatures, you find that it is a much more complex procedure than just sticking a thermometer in the ground.
In fact, to the best of my knowledge, the data I have shown you have been corrected for interfering effects. Here’s an example of some light reading.
Still, you can argue that “global average temperature” is a meaningless concept. See here.
Since 1979, satellites have been monitoring stratospheric temperatures.
Volcanoes!
However, it is not clear we know how to correctly interpret the satellite data. See this.
New (May 2003) analysis suggests the satellite data are consistent with global warming.
What do you think of this?
Two slides of data from the University of Florida:
IPCC summary report, page 31
There are lots of data on global temperature. Of the 12 warmest years on record, 11 occurred between 1995 and 2006 (2007 not included in the data), but does that mean anything?
Score after the 5th round:Global Warming Handwringers 3¾ Boss Frogs in our Bucket 1
The referee awards ¾ point to the Handwringers. Nobody gets the other ¼ point.
The referee does not believed the Boss Frogs earn any points for this round. But the Handwringers have not scored a knockout.
6. Eliminate Other Causes
Hah! Not in my lifetime. This round of the match will be going on for a long time.
Score after the 6th round:Global Warming Handwringers 3¾ Boss Frogs in our Bucket 1
7. Supporting Evidence
I’m running out of time. There’s no way I foresee getting here during a single lecture. This and the 3 slides after are from my 2006 lecture.
As one example, the sea level (a couple of slides from here) has been rising, but it is possible to argue that the sea level rise is not related to the changing temperature.I have many news reports I’ve archived on my computers, detailing “little” things that start to add up:
butterflies too far north; species found where they don’t belongice melting in places it shouldn’t“warmest month ever,” “second warmest year,” etc.
more “little” things: Austria’s glaciers (the Alps) are shrinking melting rate of Greenland glaciers is speeding up Arctic ice is melting Himalayan glaciers are melting Alaskan permafrost is thawing massive beetle infestation in Alaska (beetles not being killed by the cold) Greenland ice cap is thickening (due to increased snowfall from warmer air) Atlantic conveyer belt slowed by 30% between 1957 and 2004 January 2006 warmest US January on record Caribbean coral reefs dying after warmest sea temperatures observed in 21 years of monitoring Great barrier reef (Australia) bleaching due to abnormal sea surface temperatures
Without spending more time on this subject, I am not ready to assign points.
Score after the 7th round:Global Warming Handwringers 3¾ Boss Frogs in our Bucket 1
When you look carefully at what scientists are actually saying—and understand a bit if science-speak—you find that they are not as far apart, or as close together, as the Boss Frogs or the Handwringers would have you believe.
2008 update:
The 2007 IPCC report represents the consensus of scientists worldwide. There will still be some who believe the report goes too far, and some who believe it doesn’t go far enough.
8. Future Scenarios (IPCC)
8a. Doomsday Scenarios
Go here for some light reading. (Site dead, 2008. Just as well; it was really gloomy.)
But remember, those people are Handwringers.
Global Climate Models, which predict the future, are a source of abundant controversy. No matter what a model predicts, each side will jump on the result and say “look, this proves our point.”
We need to get the models right, so we can plan for the future. The models are improving all the time.
Another day’s lecture, and no time left.
Where are We Today?
Here’s the current situation, as I see it. Definitely changed from the last time I taught this course.
We have found a smoking gun in Prof. Plum’s study.
Miss Marple says she saw his body there.
Inspector Lestrade says there is no body.
Sherlock Holmes says lock the doors, the killer is sure to strike again.
You, the jury, should demand proof that the smoking gun actually killed the body. A panel of scientists claims to have examined the body and seen the bullet wounds. But you still aren’t sure you’ll recognize “proof” when you see it.
What Should We Do?
Options for society (paraphrasing a “Boss Frog”)”
Do nothing. Wait to see if there is really a threat. Advantage: cheap. Disadvantage: you aren’t preparing for the future.More research, but otherwise do nothing. Find out if there is really a threat. Advantage: not too expensive. Won’t do anything rash. Disadvantage: delayed action may be useless.
Limited action, starting now, phased in over time. Advantage: less expensive than tackling the problem head-on, right now. Won’t do anything rash. Disadvantage: more costly, may spend money on non-solution, limited action may not be enough.
Full control of emissions, starting now. Advantage: tackles the problem right away, quickly and thoroughly. Disadvantage: very expensive; there may not even be a problem.
What Should You Do?
Read, study, learn.
Be skeptical of claims from either “side.”
Be aware of people’s motivations.
Know whether an organization does science, or selectively chooses scientific results to promote its goals.Understand that disagreement between scientists is healthy, and not necessarily a sign that anybody is wrong.Be wary of those who demand 100% accuracy from computer models.
Watch for words that bring an emotional response (panic, hysteria, emergency, handwringer, boss frog).