Understanding Global Warming

Last week (1/21/14), NASA and NOAA released their analysis of the overall global temperatures for the year 2013. It was one of the ten hottest years on record. But as we sit here in the middle of another Polar Vortex “event”, there are still people who refuse to accept that the earth is getting warmer. I can understand this – a little bit. It’s not easy to spot gradual, long-term trends in the face of localized, short-term “noise”.

Perhaps I can give an analogy.

NASA and NOAA use as their baseline for average temperatures the years 1951-1980. As should be clear in the graph on page 3, global average temperatures were fairly even in that period. To represent the “average year”, lets take a box of 365 marbles – one marble for each day. On most days, the temperature in your location will be just about what the model says it should be. Other days, it will be a little warmer than average, and on other days, a little cooler. Let a red marble represent the warmer than expected days, and a blue marble the cooler. For the “just about expected” days, use a white marble.

For our initial baseline box, let’s use 100 red marbles, 100 blue marbles, and 165 white marbles. Take out one marble at a time to find out whether that day is warmer, cooler, or just about what is expected from the baseline model. Doing it like this also lets us take into account seasonal variations. It’s going to be warmer in the summer, but since we are comparing the actual to the expected temperature, we don’t need special marbles for the summer. You will get warm spells where you pull out four or five red marbles in a row, or cool spells where you pull out a couple of blue marbles in a row. But over the course of the 365 days/marbles, things will even out – which you can only tell from looking at the holding tray where you put all the marbles after you take them out of the box. Did I mention that you cannot look into the box of marbles?

Now let’s add global warming to the analogy.

Before you put all the marbles back into the box to do the next year, take away two or three blue marbles from the mix and replace them with red marbles. Technically, you’re turning blue marbles into white ones and white ones into red ones, but this saves you a step. Now take the marbles out one at a time again. With only two or three marbles having changed color, you’re probably not going to notice the difference among the 365 marbles.

Do it again – replace a few blue marbles with red ones. Repeat. By the time twenty “years” have passed, your marble ratio will be something like 125 red, 165 white, 75 blue. You can still get cold spells of four or five blue marbles in a row, but there won’t be that many of them. And there will be a lot more warm spells. And when you look at your holding tray at the end of each year, you should notice that overall, the years have been getting slowly redder…

From one year to the next, you’re not going to notice any real difference. You have to look at time scales several years long. Most people can’t do that. To be fair, a lot of people have more important things to do (and sadly, we no longer trust our government or any other authority to be fair with us), like worrying about the sluggish economy or unemployment. Those are far more pressing concerns for most individual Americans than something that will be a problem ten years from now.

The nation of Kiribati also has those problems. High unemployment, a depressed economy, dwindling resources. Certainly, they’d like to be able to deal with those. But Kiribati is a group of small islands in the Pacific Ocean. And if global warming continues, sea levels will rise to the point where those problems won’t matter anymore – because the entire nation will be underwater. No wonder President Anote Tong has been buying higher land in Fiji, trying to arrange special refugee status in Australia and New Zealand, and is actively encouraging emigration. “To plan for the day when you no longer have a country is indeed painful but I think we have to do that.”

The rest of us need to plan, too….while we can still afford to.

2 thoughts on “Understanding Global Warming

  1. Thank you. This is an excellent analogy, and very similar to my listing “record warm” days each year and “record low” days.


  2. Pingback: 2014 in Reveiw | Pure Blather

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