May 14, 2014

I Bleeping Love Science

Well, that's it. I've come to the end of a broad overview of planetary science as it pertains to climate change. Affectionately known as 12.340x, it's a course (online through edX) on Global Warming Science, given (mostly) by MIT's Kerry Emmanuel.

In contrast to the World Bank's course on climate change that I had taken earlier (through Coursera), this one was all about the science, and explicitly not about policy. In twelve weeks, it surveyed topics like paleoclimate, the composition of the atmosphere over earth's history, heat transfer of all kinds, atmospheric and ocean circulations, the carbon cycle, forcings and feedbacks, and finally a little bit about the models that need to incorporate all of that in order to give us a sense of where we're headed next.

When you start to get into the details of how it works, you get your nose rubbed into it: our planet is stunningly beautiful.

As a single example, take the thermohaline circulation: it's the large-scale ocean flows, driven place-to-place differences of temperature and salt content, that churns the oceans and help transport heat from tropical regions towards the poles.

The "conveyor belt" looks a bit like the blood circulation in the human body. In the Atlantic, waters flow at the surface toward the North Pole (mostly scrunched into a narrow strip: the Gulf Stream), then sinks down, flowing back toward the South Pole at large depth. In one of the problem sets you got to estimate how long it takes for a parcel of water to go from the coast of Greenland to the coast of Antartica: about 400 years.

The currents at the ocean surface are modeled, and rendered in a mesmerising visualisation that replicates all the features of the real ocean. Find it here (on the website, click the "View Movie" image to start the visualisation).

It's hard to say what I find more stunning: the beauty of the planet, or the scientific wherewithal to understand it and describe it to the point that you can arrive at a reasonably accurate, albeit virtual, replica of this highly complex system.

The rest of the course was in a similar vein. Having immersed myself in climate change issues for the past year, I'm familiar with most of the concepts, but to actually crunch through a few equations, and to work out some numbers yourself (I had to revive my scientific calculator for the problem sets), really starts to open the window that before was only ajar. I had quite a few Aha! moments.

I took the final yesterday. And am already wishing there would be a follow up course. I feel I want to go deeper than this overview, the introduction serving as a come-on, a bait. Hard to resist.

The whole delivered by Kerry Emmanuel in a steady, calm voice, methodical and, accurate. I could hear that voice right through this marvellous piece Emmanuel wrote for FiveThirtyEight, a devastating rebuttal to a climate denier piece by Pielke Jr.

MIT students have an acronym to be applied to situations of exasperation, usually at the workload: IHTFP. One cleaned-up version of the acronym (trotted out for the benefits of parents who, after all, pay at least part of the tuition) is "Institute Has The Finest Professors". I guess you can point to Emmanuel in support of the latter interpretation.



You may also like:
1. Watch "Years of Living Dangerously" - but not alone
2. National Climate Assessment: Why I'm Cautiously Elated


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