april 12 times beach video april 14 video discussion april 19 alternative energy april 21 global...

April 12 Times Beach

Video

April 14 Video Discussion

April 19 Alternative

Energy

April 21 Global Warming

April 266 Student Talks

April 28 10 Student Talks

May 312 Student Talks

May 53 Student 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 35 Talks

April 26 (6) April 28 (9)Hilkemeyer BradyHuff FischerJones Gavin-EllisonMcFarland GregoryRohrer HarrisVandemark Jenkins

KueckReevesVenayagamoorthy

Other (3)Kipp, Dotson, Toscano

May 3 (11) May 5 (6)Bassett ButlerBukulmezer DuvallCulen HaasFaison Lester

Gorham McConnellGutierrez ToddNaitoNewmanPeasleeSaundersThompson

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)

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 says 35 minutes. Park web site says 45 minutes.

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.

Government agencies such DOE (Department of Energy), EPA, NOAA, USGS, NASA.

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.”

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.

Unfortunately, this seems to have 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.

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 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.

They’re even holding a “World Naked Bike Ride Day” in June to protest! If you can’t make a point with your clothes on, I question whether you have a point to make.

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/

http://www.skepticism.net–this is tricky!

I would like to encourage informed skepticism. I am disturbed by skepticism based on personal biases.

The latest posting to this site (April 20, 2004) is dated January 7, 2004. There are 10 headlines on the site.

I see 4 headlines and I say Yes! Yes! Yes!

I see a headline and I say No! No! No!

I see 5 headlines and I say 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.

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Let’s focus on the planets out to Jupiter.

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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.

If you’re keeping score, the planetary greenhouse effect is real and significant.

Score:Global Warming Handwringers 1Boss Frogs in our Bucket 0

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 comes from http://globalwarming.enviroweb.org/. The site’s use of frames makes it difficult to give a link for each quote.

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 appear to be correlated with the atmosphere’s CO2 content.

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?

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

3. Evidence of Human Influence on the Atmosphere

The claim is that CO2 generated by humans is—or might be—enhancing the planetary greenhouse effect.

Let’s see how that works.

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.

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.

Now add an atmosphere. The atmosphere absorbs some of the earth’s energy, warms up, and radiates energy in all directions.

Now add an atmosphere. The atmosphere absorbs some of the earth’s energy, warms up, and radiates energy in all directions.

http://globalwarming.enviroweb.org/ishappening/ishappening_frameset.html

20000 yrs ago

http://www.grida.no/climate/vital/02.htm

http://www.usatoday.com/weather/wgrnhse.htm