I will ponder Middle East tensions later; today I’m staring at a perfectly flat ocean solving easier problems. But first, would anyone anywhere ever say, “I’m from the Middle East?” In other words, does anyone actually identify with that label or is it just something western power brokers made up?
One of our new on-board lecturers is Peter Varley, a meteorologist, which is a person who studies things in the atmosphere and who has cleared up a couple puzzles for me.
I was pondering a few posts ago why rainbows seem higher in the sky than I am accustomed to. My conjecture, nowhere near the level of a theory, was it had to do with latitude. I now know it doesn’t. It has to do with elevation above the ground. I have generally watched rainbows from ground level (our 16th floor condo doesn’t look the right direction;) now I generally watch them from Deck 7, sometimes Deck 10, which are probably 50 to 70 feet above the water.
Rainbows happen in the east when the setting sun hits relatively large raindrops, or the west with the rising sun. The light is refracted as it enters the drop, then reflected off the interior wall, and again refracted as it leaves the drop. That adds up 42º, based on the relative speed of light in air and water, for the red end of the spectrum, regardless of your latitude. The angle from the refraction, reflection, refraction varies slightly by frequency, which spreads the light out into all the colors of the rainbow.
When the sun gets higher than 42º, almost halfway to vertical, from the perspective of the observer, the rainbow doesn’t happen, regardless of latitude.
However, if some rain drops are large enough, the light reflects twice as it tries to escape from the drop (refraction, reflection, reflection, refraction) then there is secondary rainbow, higher and generally weaker than the primary. The angle then is 47º for red, a little beyond halfway to vertical. It is possible to get even more reflections inside the drop with larger and larger angles. Some will go all the way around and very occasionally produce rainbows in the east in the morning and west in the evening. The photo above is a double rainbow; the photography isn’t very good.
And with a little reflection, that should clear up any questions on this topic.
A tougher topic addressed in another lecture is climate change. First, a few points that Varley emphasized; none that are scientifically controversial but unfortunately some are politically contentious:
The climate is complex system in a delicate state of balance. The Earth’s temperature is complicated, affected by solar activity (e.g. sun spots), the Earth’s orbit, the Earth’s inclination, pollutants in the air, the reflectivity of the surface, and the greenhouse effect. All of those factors vary; none are completely under our control; some are completely beyond our control and always will be. As far as geologists are concerned, we are in an ice age right now because we have ice on the surface of the planet. (More specifically, a period of glaciation, which is the least intrusive type of ice age.) With no greenhouse effect, the Earth would be a frozen ice ball with no liquid surface water. So far we should be ok.
The Earth’s atmosphere is warming.
Top of the list of greenhouse gases, in some order, are water vapor, methane, ozone, and carbon dioxide. All of these are important, either because they are very effective at trapping heat or because there are large concentrations in the atmosphere or both. Water vapor is by far the most important because there is so much of it. Methane is a much more powerful reagent although far less abundant. A significant source of methane is ruminants, e.g., cows, camels, water buffalo.
Carbon dioxide is a common (but less common than water vapor) and powerful (but less powerful than methane) greenhouse agent. Over the entire history of the planet when it has had an atmosphere, the average global temperature is highly correlated with the level of CO2. The level of CO2 has been increasing exponentially since the beginning of the industrial age and the associated increase in burning of fossil fuels. Average global temperature has been increasing right along with the CO2.
[ The ugly part of cruising. I took this because it is unusual for our ship; our exhaust rarely shows at all. With perfect combustion, you would get heat and the by-products, H2O and CO2, both of which trap the sun’s heat. You don’t get the pollution that blocks the sun’s heat.]
Some things that Varley touched on, which keep being repeated in the media and in political speeches although they are serious misunderstandings, distortions, misrepresentations, total nonsense, or outright lies.
Number One: global warming is a hoax, fabricated by the Chinese to make American business non-competitive.
Nonsense or outright lie, scientific concern about climate change has been around for 50 years or more, long before the Chinese were on anybody’s list of economic powers. Most of the same people, with a different audience, will also say . . .
Number Two: global warming is a hoax, fabricated by scientists who have a vested interest in having funding agencies believe that it is true.
No, questioning your adversary’s motives is never a valid form of argument and there is no shortage of research topics for academics to work on and obtain funding for. It’s not in any researcher’s interest to waste time on non-issues; you won’t get published. It is tempting to speculate about who has a vested interest in global warming not being true, but we won’t talk about motives.
Number Three: the switch in nomenclature from global warming to climate change is a tacit admission that the globe isn’t actually warming.
No, the intent of the change was to eliminate confusion and obfuscation and to broaden the discussion. An increase in average global temperature does not mean the temperature will increase uniformly everywhere; this switch should have eliminated the specious argument that global warming can’t be happening because we had a cold winter where I live. Because of changes in ocean currents and jet streams, some places will get warmer, some colder, some drier, some wetter, some will have longer growing seasons, some will become deserts. Climate is changing because, on average, the globe is warming.
Number Four: Correlation does not prove causation.
This is a simplistic truism from Statistics 101, trotted out whenever someone doesn’t like the inference. The tobacco industry hid behind it for decades, which was good for their vested interest (this is a statement about the profitability of big tobacco and the size of tobacco executive bonuses in the 20th Century, not anyone’s motives) and bad for a lot of people. It wasn’t relevant then; it’s not relevant now. Correlation can imply, not prove, causation if we have theory to back it up. The evidence is circumstantial but it is powerful when we know the underlying mechanism linking the correlated factors. We do know the chemistry of how tobacco causes cancer, how CO2 traps heat, and how the industrial age increased the CO2 level. Unless you have alternative explanations for the data, don’t say the correlations don’t count.
Number Four(A): When the temperature increases from natural causes, the oceans release more CO2, hence the warmer water causes the increase in CO2, not the other way round.
OK, that’s the alternative explanation and almost right until the end: warmer water does cause the increase in CO2 AND increased CO2 does cause warmer water. This is another half truth that raises a doubt but doesn’t explain the industrial age effect or identify any natural event tied to that time line that could have started the loop.
As the CO2 increases, the ocean temperature increases, which increases release of CO2, which increases the temperature. This is a positive feedback loop, which operates like compound interest: the more you have, then the more you get, then the more you have, and on and on. Whether or not there are natural causes contributing to the loop, our burning of fossil fuels certainly is adding CO2 to the atmosphere, which isn’t helping.
Number Five: Your own data shows that, while global temperatures had been increasing recently, it has plateaued several years ago, implying a natural cycle not caused by humans.
First, if there was a plateau for a handful of years, it is over; temperatures are on the rise again. The overall trend continues to be up. If, as some climate change deniers have said, we shouldn’t read too much into the climate data from a geologically short time period, like the 250 years since the beginning of the industrial age, then we certainly shouldn’t read too much into the weather data for an eight or ten year slowing of the rate of increase. There will be from time to time, variation in the rate due to all the factors affecting weather and climate, as the deniers often remind us. The correlation between global temperature and CO2 level is still as strong as ever.
Number Six: OK, maybe the globe is warming and maybe CO2 is contributing to that, but most atmospheric CO2 doesn’t come from human activity.
True but misleading. Whatever the share of the CO2 is that we contribute, it can have a dramatic impact. Remember positive feedback loops (I only mentioned the one; surface reflectivity is another) and compound interest. And it matters how you do the accounting. Do you assign to our use of fossil fuels only the CO2 that comes directly from burning the fuels and assign to nature the CO2 that is released from the oceans. Or should we also get credit for the increased release due to the increased temperature due to our use of fossil fuels. (It’s easier to obfuscate this discussion than to enlighten it.)
The climate is complex system in a delicate state of balance. Even small changes will alter that balance. Homo sapiens have risen to dominance during a geologically short phase of Earth’s history with an incredibly favorable climate. How much do we want to fiddle with the balance?
Number Seven: Rising sea level from melting glaciers is a myth (Blame another bunch of scientists;) we have more glaciers now than we did 20 years ago. And did you ever see a glass of iced tea overflow as the ice melts?
Misleading at best: We do have more glaciers if you count as separate glaciers the pieces that were once part of a single large glacier but aren’t now because so much of the large one has melted. The iced tea analogy only works if all the ice in the world were floating on the oceans. It isn’t. Almost all the frozen water (over 90% if I remember correctly) is sitting on the land masses of Antarctica and Greenland. As it melts, the oceans rise; the Maldives, the Netherlands, and Florida shrink.
If a meteorologist were to tell you that there is a 90% chance of rain, would you consider that when planning your picnic or wedding reception?
Varley believes, based on his reading of the research, that it is 90% certain human activity will increase global temperatures enough to have serious consequences for the planet in this century. The 10% uncertainty does not mean there is scientific uncertainty about whether we are altering the climate; we are quite certain of that. What we are uncertain about are how much we are altering it and what the consequences will be.
Are we so sure of what we are doing that we are willing to jeopardize the planet’s future? Or do we just throw up our hands and say it’s too late; nothing we can do; let another generation with better technology worry about it.
We are absolutely awash in free energy. The problem is that it isn’t always where we want, when we want, in a form we want. Henry Ford once said, “If I had asked my customers what they wanted, they would have said a faster horse.” If you ask the energy companies what we need, they say, “Offshore drilling, fracking, ‘clean’ coal, access to wilderness reserves.”
A better answer is better batteries.
What’s the worst that can happen if we abandon fossil fuels and our planet isn’t warming after all? We spend a lot of time and money (which translate to jobs) to bring our CO2 emissions under control needlessly and all we get for our trouble are cleaner air, cleaner oceans, pristine wilderness, and a generally nicer place to live.
“The stone age didn’t end because we ran out of stones.” Thomas Friedman
“Climate is what you expect; weather is what you get.” Attributed to Mark Twain but probably not original to him
“Scotland has the world’s worst weather and the world’s best climate; Minnesota is the opposite.” I think I heard the first part from my grandmother; the second part is mine.
3 thoughts on “Meteorology”
You clearly enjoyed this lecture and writing about it. I love how you and Varley addressed the common talking points. In addition to the number of benefits from researching and using alternate energy resources, one could/should add the likelihood of new technology that applies to other areas. Thank you for a wonderful post. Oh, and thanks for the explanation of rainbows. I saw one with lots of color variations just a couple of days ago. It didn’t make up for wet shoes but such a treat to see.
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I’m not sure ‘enjoy’ is the right word; it is certainly something I think a lot about and this trip has certainly brought home.
I would rather think more about rainbows, diverse cultures, exotic places, plants, and animals, spectacular scenery, and stimulating conversations over leisurely meals. And less about climate change, habitat loss, extinction, trash floating in the open ocean, and human rights abuses.
Great essay, Ron! I only wish that the GOP president would read it.