Is Climate Change Real? [Part 1]
Polluted Countries Feel the Burn
With a burning desire to plot some more graphs and armed with intuitions I was curious to verify, I couldn't resist taking on the issue of global warming by the horns.
The way the world tends to treat global warming resembles in more ways than I would like to admit it to the way Westeros deals with the White Walkers: everybody knows it's coming and can attest that the threat of paramount importance. Both our people and those peopling the lands of George R.R. Martin are more or less conscious that whatever concrete manifestation the issue ends up taking, it will most certainly turn the most pressing of international conflicts into a pathetic puppet show. Yet, rulers and citizens alike manage to go on with their lives while neatly sweeping the topic under the rug, akin to sailors preoccupied with the sharks threatening their ship as they are floating atop a massive wave that threatens at any moment to engulf them - along with their sharks - into eternal darkness.
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Enough drama, the message should be clear: global warming is conveniently named to spare me from mentioning its scope, and it is believed to be affecting the here and now. Or is it? Is the entire world's average temperature undergoing a severe increase; are precipitations levels plunging worldwide? Alternatively, could it be that global warming is selectively taking its toll on specific regions of the world based on a hidden variable? With a burning desire to plot some more graphs and a few intuitions I was curious to verify, I couldn't resist taking on the issue of global warming by the horns.
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However, I should first note that the bull is indeed a fierce one, and that the claims and results presented in this article and the one following in should be taken as what they are: a bunch of more or less successful attempts by a burgeoning data scientist to gain some insights into the tremendously complex topic of global warming. Ideally, the project would have been larger in scope, encompassing every major city on the planet and plotting larger time spans. While my code was generalized enough to gather these information, my computer is far from being up to the computational challenge.
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With the motivations strongly rooted in the back of my mind, I thus engaged in the infamous data collection period. I'll spare you the details of that temperamental showdown, but the big picture was that I went ahead and collected from the weatherunderground website monthly averages of temperature and precipitation for every month since 1926 corresponding to an arbitrary location in the US: Ithaca, NY. Once the data was in my possession, I made a few additions, notably adding a normalized average temperature for every year by subtracting from each yearly average the mean temperature over the entire time span.
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If we believe the occasional media accounts and the even more expressive movie depictions - Kingsman, I'm looking at you -, we should expect a massive rise in temperature and a decline in precipitation over the years. Unfortunately, the precipitation data gathered for Ithaca was not exploitable because it mostly hovered around flat zero. On the bright side, the temperature data was nicely formatted and ready to be plotted.
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I first went ahead and plotted the temperature variation in Ithaca over the years:
If it looks like I did everything in my power to sound like VSauce in this paragraph, it's because I did.
Surprisingly, there is no distinguishable pattern in the evolution of average temperature over the years. Shocked by the results, I felt the need to investigate other possible explanations. For example, perhaps the increase in temperature can only be detected when looking at the variation of temperature across the same seasons, rather than collapsing every season of the year into a single point. I thus decided to group the average temperature values by month, and to assess the variation of the temperature values for a single month over time. Here are a few of the graphs that I obtained through this procedure:
The graph on the right is nothing more than a zoomed-in version of 3 of the 12 graphs displayed on the left. Once again, there is no sign of global warming when looking at the data for Ithaca. But Ithaca's weather fluctuations constitute no more than a fragment of the big picture. I thus decided to move on to the analysis of other regions of the world, because no single point can be taken as representative of the set to which it belongs. This time around, I wanted to explore the intuition that more polluted environments might be more susceptible to climate change. I therefore gathered data corresponding to New Delhi, India and Cubatao, Brazil, two of the most polluted cities in the world. The results I obtained were quite different, and certainly more revealing of the global warming crisis.
Following are graphs retracing the evolution of average temperatures in Cubatao over the same month. This time around, as it appears on the zoomed in graph there is an explicit escalation in temperature values along the more recent observations, especially in the summer months. Moving on to the month summary, we find this increase pattern for all but three of the twelve months.
Normalized Temp in August, Cubatao, Brazil
I had to reserve the best graphs for last: the following two plots illustrate the variation of precipitation levels in New Delhi over a period of only 20 years (1996-2016). Yet, as you can see for yourself, this brief time span was enough for the rain levels to drastically decrease. This ominous signal coming from the most polluted city in the world - as of today - is a real slap in the face for anyone underestimating the potential dangers of global warming.
Precipitation Over Years, New Delhi
It thus appears that polluted regions tend to be rather severely affected by the global warming crisis, while greener regions have yet to be confronted to the full blow of climate change. At this point in the exploration process, I couldn't help but wonder: is there any correlation between the pollution levels of a country and its overall development? For if that were the case, we would be faced with the stark realization that the fundamental inequalities that plague this world extent beyond the realm of man-made metrics, such as access to education or gender equality, and onto the natural environment itself.
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Now that the link between climate change and pollution has been investigated, here is a link to the answer I sought and found as to whether pollution and overall development are related.