OK, a play on words, I couldn’t resist. My apologies.
The recent spate of winter weather, especially in the American South, might lead many to doubt scientists claims of climate change. Even many of those who support climate change science but lack the technical expertise and who rely on true experts may find themselves doubting. To those folks, I say, “You are fine. These “Polar Vortices” the media are making famous may seem inconsistent with climate science, but, never fear, they are totally congruent with climate change science.”
But, me telling you “supporting climate change is fine” needs some supporting evidence from me. Saying, “Never fear” is not enough, in my book, to help educate the, …uhm, “under-scienced.” I include myself in the under-scienced, as I personally don’t feel I know enough, and as a statement of fact, I don’t know enough. In spite of my lack of knowledge, I do know some things. Like, some climate change deniers need to be brought back to Earth in their denial of climate science, though.
First, we cannot forget climate change is really “global climate change,” making deniers, “global climate change deniers.” The other term, “global warming” is not synonymous with “global climate change.” The descriptions are not equivalent. The preferred term is “global climate change.”
Another failure of denier logic is attributing global effects to local areas. I should have saved the tweet which provided the impetus for this post. The tweeter said something to the effect, “It’s snowing in Atlanta! See, global warming is a leftist myth!” Instead, I’ll have to offer some surrogates:
Left lying about climate change to consolidate power like they r lying about MASS CARE so u’ll accept #obamacare!
It’s cute watching leftists who believe in “Climate Change” (based on a couple hundred years of data) mock the #creationdebate.
I’m not going to pick these apart; that is not my goal. These tweets are merely representative of some wrong-headed thinking. Having said that, let me take issue with a couple statements.
Politics can lie, for sure. Science, good science, real science, is not about lying. Science is about presenting evidence, data, and research which can be consistently reproduced. Reproducing experiments is, in fact, encouraged. Facts, by definition, cannot lie, nor are they opinions. People can, and do, lie. The underlying science does not lie. Opponents of global climate change might as well claim, “the value of Pi is a lie,” or, “the speed of light is a lie,” or “gravity is a lie.”
As for climate data, accurate historical climate records can be extracted in a variety of ways going back thousands of years, hundreds of thousands of years, even millions of years – not “a couple years.” The science of dendrochronology incorporates climate in dating tree species. Dendrochronology can give us accurate records going back almost 11,000 years. A friend of mine is a dendrochronologist. Please tell her to her face she can’t determine climate from her trees. I dare you.
We can also tease climate details from pollen in buried soil samples. Look around your environment. Now, imagine your environment 8,000 years ago. Think it was same as today? Maybe. It is possible. Though, if you are a current resident of Sahara, 8,000 years ago would have seemed like a paradise compared to the desert we see today. We know from radar imaging, satellite imaging, and boots-on-the-ground research the Sahara of today was a grassland/savanna several thousand years ago, with several large lakes. We can examine lake sediments. We can examine sea floor sediments. We can examine the stratified layers of Greenland and Antarctic ice sheets. These data sources will take us back hundreds of thousands of years. Ignore Ken Ham. He has no idea what he is talking about. In 2007, a Pennsylvania age Mire Forest was discovered in a coal seam in southern Illinois (SMNH/ISGS). Dated to 300 million years ago, we can see for ourselves how the climate must have been, given vegetation as evidence.
Even climate change advocates miss the bus, though, unfortunately. We cannot argue a snow storm in Atlanta is “evidence of climate change” any more than deniers can state “climate change is based on a couple hundred years of evidence.” Neither is correct.
Climate is the long-term, typically 30 years or longer, cumulative evidence of atmospheric phenomenon. “Phenomena” means statistics, and may be distilled down to two basic attributes, temperature and precipitation. Climatologist examine yearly average temperatures and precipitation types and amounts. A single snow storm event in Atlanta, Georgia is evidence of nothing. Even two or three events is possibly meaningless. This would be like me proclaiming, “Wow, the United States must be doing a great job educating students!” based on using 2 or 3 SAT scores acquired from a few people who took the SAT one Saturday morning.
The snows in Atlanta 2014 can become a talking point for global climate change, though, and lead to some real scientific explanations.
- What conditions might lead to a consistent, yearly winter snowfall in the American South?
The explanation is actually fairly straight-forward. The ability of a cold air mass to maintain water vapor is pretty low. Why? The answer lies in heat. What is heat but energy of molecular motion, right? Less motion implies less heat, and objects with a low molecular energy feel cooler or cold to us. Cold air contains air molecules with low energy and air molecules are more likely to form bonds with other slow (cooler) air molecules. Warmer air contains air molecules with higher energy, the higher energy makes forming bonds between water molecules challenging and water is more likely to exist as water vapor. Think of kids on a playground playing tag. Think of the “tag” as forming a bond. Faster kids are harder to tag (bond to) than slower kids.
To us, the difference of a few degrees might not seem like much, 20°F or 27°F is still pretty freaking cold. But, +7F° means more energy, and more energy means the potential for more water vapor is greater. Perhaps, our air temperature is 37°F; even more potential for more water vapor. Still seems cold to us, but the potential difference in water vapor available for condensation is huge.
Now, as long as air temperatures in the atmosphere remain fairly stable, we have nothing to worry about. No one would know about the water vapor composition of the atmosphere around Atlanta except for a few meteorologists and climatologists. Unless, of course, the circulation of global air masses result in a cold, dense air mass intruding into the lighter, moister air mass around Atlanta.
Energy (heat) always move from most the most energetic source to the lesser energetic substance. In the case above, heat is exchanged between the warmer air mass and the cold air mass. The water vapor molecules, once flying around in the warm air, give up their energy to the colder air molecules and become more susceptible to becoming bound to other molecules and condensing. And, they will condense, fast and furious, especially if the temperature gradient is large (the difference in temperature between the two air masses). The greater the gradient, the faster the condensation will occur. The January 2014 Polar Vortex represented a very large difference in temperature characteristics compared to the warmer, more moist air from the Gulf of Mexico.
I don’t recommend trying the following, but you can. Boil some water. When the water is at very low boil, just when the water at the bottom of pan begins to vaporize and very small bubbles form, you can still safely dip a finger in the water at the surface. Not too long, and it may be uncomfortable, but it can be done. The water in the pan is not a uniform temperature. As the water in the pan heats, the very warm water at the bottom will circulate to the top. The water molecules are less densely packed because they are closer to the heat source, and enervated with this new energy, and try to find new and open territory, like people who begin shoving in a crowd of people. Sort of like what happens when your dog gets out. Inside the house, the dog sort of walks around at a low energy state. But, open the door (our “heat”) and she runs out and flies around the neighborhood. Back to my example: the water is not only rising under its own, enhanced with this new energy state, but also the water is being displaced, pushed up by cooler water descending from the surface to the bottom of the pan and displacing the warmer water up.
If you’d rather not use your finger, try your spouse’s 🙂 If that doesn’t work, either, then you could be a little more scientific. Use a meat thermometer. Those usually have a temperature range which more than adequately covers the temperature realm of water. Place the tip of the thermometer about 1/2″ under the surface and take a reading. Probe a little deeper and take another reading. Keeping going until you are just about the bottom of the pan. The gauge will respond immediately to the movement of the probe through the vertical water column. Depending on the size of pan and the amount of water you added for this experiment, you could see 30F° difference between the surface and the bottom.
Our atmosphere is like this, a fluid, heated at the surface and displaced upwards as cooler air above descends and moves under the lighter, less dense air. Add in the Coriolis Effect, local and regional pressure differences, plus surface friction (and a few other contributors), we have weather. Sounds simple – hopefully; but, weather is anything but.
And, boom, Atlanta gets some snow.
When global temperatures rise, no, scientists cannot predict the effect of a global effect on a local area, no more than I can predict national SAT scores from a small sample of scores. More accurately, I can predict national SAT scores, I just should not expect a high degree of confidence in my predictions with such a low pool of samples.
Climate science does not use a mere hand-full of data points for performing any modeling. Climate science does not simply use data points collected over a couple years, or even 200 hundred years. Climate science uses a wide variety of data points spanning hundreds of thousands of years from many different sources.
Meteorologists are getting better at forecasting weather as their tools for doing so improve. Satellites, aircraft, drones, radiosondes and rawinsondes, and NEXRAD systems provide amounts of data without equal in human history. Even with our sophisticated instrumentation, scientists cannot precisely predict how air masses will mingle nor accurately forecast the effects the that mingling. Not yet, anyway. But, is that really necessary?
Let’s think about our pot of water. You could dye the water to see how mixing occurs. Or, paying attention to your boiling water next time you make spaghetti. I add a little olive oil to my water. What how the oil and water mix (or don’t). Watch the eddies and currents develop as the addition of heat changes the dynamics of the fluid. Now, let me ask you this: Is it really important to know precisely how each eddy and current affect the entire pot of water? Probably not. What you are concerned with is not the changes in the circulation pattern of your fluid, you simply need the fluid to boil and become hot enough to cook your spaghetti. But, you added heat, and that changed the overall (the mean, average) temperature of the water in the pot. In fact, the mean temperature of the water in the pot increased, more than doubled, likely. As we heated the water, some water heated fast, rose, and the void was replaced by cooler water, cooler water surrounded by water at a higher temp, probably. This is a very dynamic environment, our pot, so noting these changes in temp would take a complex array of sensors in the water.
The pot is our Earth’s atmosphere. As Humankind changes, alters the atmospheric chemistry, adding more gases which encourage heating, or the storage of heat, even small increments in atmospheric temperature will increase two important variables. First, the amount of water vapor which could potentially be available will increase. Second, the amount of evaporation will increase. Added heat will make room in the atmosphere for more water vapor, and also add more water vapor through evaporation. As these air masses with enhanced proportions of water vapor circulate, eventually they will bump against a cold front, resulting in unprecedented rainfall, snowfall, or perhaps unusual amounts of hail.
The bottom line is this: snow in the American South, increased rainfall in some areas, drought in other areas, is completely consistent with what one should anticipate with a changing climate.
The more data collected, the better and more granular data gathered today is and into the future, the better our climatological models will become. The United States could afford to improve the density of atmospheric sensor systems around the world and greatly improve the quality and quantity of atmospheric data. The result would vastly improve the knowledge of our own atmosphere and provide us with enough information to really understand the complexity of our planet’s atmospheric physics and chemistry.
Thanks for reading.