Sunday, November 1, 2015

Day After Tomorrow

Alright, this movie actually made me laugh. Multiple times. For those of you wondering, Day After Tomorrow is actually an amazing movie, and well worth the watch. If you go in expecting a comedy. If you go in expecting a super accurate physics representation of global warming, the end of the world, and temperatures falling at 10 degrees a second.....

However, this week I won't be evaluating the physics of this movie (which is a shame, there are so many great places I can go with "10 degrees a second"). Instead, I will be talking the problem of global warming. Specifically, How does the modern rise in temperatures compare to historic fluctuation in global temperature. Surely everyone remembers learning in elementary school about the ice ages and the mammoths running around every where. And that one land bridge in the Bering strait that they always thought was so important to teach everyone. So clearly the planet has had some cool points, and seems to be in or on its way towards a hot point now. How does this look throughout history?

Well, Humanity as a species started taking measurements of the global temperature all the way back in the 1880's. Unfortunately, I was only able to dig up records dating until the 2010's, but it still should give us some sort of an idea, right?

From NASA's records

OH DEAR GOODNESS WE ARE GOING TO DI..... wait, the entire y-axis covers only 2 degrees Celsius. However, the global temperature is right around 0 degrees Celsius according to NASA. If one of the scary things about global warming is the polar ice melting, ice melts at 0 degrees Celsius. Obviously, the poles are cooler than the global average, that is what an average is after all. But if you start increasing the global average, the poles will increase too. Eventually, the poles hit 0 degrees Celsius and then....

So, that is only dating back until 1880. We know the ice ages were a bit further back. So how are we supposed to know what the temperature is before we took measurements? We can actually estimate what the global temperature was using clues from things such as tree rings and other proxy data sources. You take a bunch of proxy data sources from as far back as we can figure and put them together, and you get something that looks (something) like this:

Ok, so the scale on this graph is a bit bigger, but it points out an interesting note: The Earth seems to have been hotter, much hotter, in years past. Considering best evidence dates humans anywhere from 200,000 to 10 million years ago, we as a species likely didn't live through the incredibly hot temperatures, however there is a chance we have lived through temperatures hotter than the current ones. What does that mean for modern man and global warming? Well, I leave that to someone smarter than myself.

P.S. in case you were wondering, in 3015, global warming has not ended humans. Not to say it won't, but so far we are still kicking.

P.P.S. Why on earth is the movie called "Day After Tomorrow"? It never references that line at all, the whole movie takes place over a week or two, and just in all ways the name seems ripped out of nowhere. But whatever.

1 comment:

  1. I like that you have multiple plots, with important data. However, you didn't really argue a particular point, other than maybe that there have been temperature changes in the past, possibly even higher temperatures than we are experiencing now. But there are a couple points you missed. On your first plot, the y-axis is the "temperature anomaly" or temperature deviation. So it is not the average global temperature, but how much the global average has changed from what it was in 1950. So, by 2010, the Earth was 1.0 deg Celsius warmer on average than it was in 1950. With regard to your 2nd plot, the scary thing is to notice how fast the temperature has been rising in the last 100 years -- it's the nearly vertical spike at the very right edge of the graph. Such a rapid rise is unprecedented in at least the last 20,000 years.