Just as conservatives complain each December about the war on Christmas, I think it's time that we on the other side of the spectrum complain in January about the war on climate change.
It happens almost like clockwork, every single year. Sometime in January, usually right after Christmas, a cold snap or a blizzard or some other cold weather event occurs, and a bunch of climate change deniers come out of the closet to tell us that climate change is a hoax.
And so this year and every year I find myself writing a blog entry to defend the science of climate change. It is unfortunate that we live in a world where it's necessary to defend sound science, but that's where we are, and so that's what we will have to do.
Yes, it is true that in the last few weeks we have experienced record low temperatures throughout the United States. However, a simple cold snap is not an indication that global warming is a hoax. A simple review of statistics shows that this is the case.
Consider the stock market. The stock market is an excellent point to begin our defense because the same people who routinely challenge state-of-the-art climate science also happen to be big fans of the stock market.
The stock market goes up and down. No matter what time frame you look at, whether it is a single hour, or a month, or a year, any evaluation of stock market averages shows the market bouncing up and down, up and down, up and down. We have all seen the charts that look like jagged mountain ranges. These up and down movements occur because the stock market is a series of random events. Random systems move up and down. It is what nature does when she is left to her own devices.
For a person who is looking at the stock market for investments, the up-and-down action of the market is irrelevant. The only thing that the stock market analyst cares about is the general trend. The averages can move up and down by a large amounts every day, but if the averages gradually rise all over the long run, the stock market remains a good investment. The stock market analyst would be (and should be) unconcerned if the stock market falls 5 days in a row. Nor is the stock market analyst going to be concerned if the market falls by a large amount in any single day. What matters is the overall trend. If the trend is up, the market is favorable.
The point is, the day-to-day changes in stock prices are random, but the long-term changes in prices reflect deeper economic conditions -- economic crises, slow growth periods, recessions, or boom periods.
The weather is it exactly the same. Like the stock market, weather behaves randomly on a day-to-day basis, and may move up or down on any given day. The long term trends, on the other hand, represent deeper environmental conditions. So five days or even 10 days of below average temperature do not matter any more to the overall weather trends weather than day-to-day stock prices matter to the overall economy.
If you were deciding whether to invest in a stock or not, would you be more concerned about the change in the stock price over the past five years or the past five days? The answer is obvious. In the same way, if we are going to evaluate global climate trends, we are not interested in what the temperature is today or yesterday or the day before. We were only interested in what the temperature is over the long run.
So, if average global temperatures have increased over the last five years, would you predict that 2014 would be warmer or cooler than average? You would, of course, expect that if the last five years were the warmest years on record, the current year 2014 would also follow the trend. Not rocket science. Things tend to keep doing what they have been doing, if the current underlying conditions remain the same.
Another way of looking at this is to ask yourself if five days of below average temperature in United States is enough to drop the temperature average for the whole country over the next 365 days. Again it seems perfectly obvious that no the matter how far below average the current temperatures may be, it is not likely that 5-7 days of low temperatives will affect the average of the next 360 days very much. 365 days are a lot of days, and it would take probably 100 or so below average days to make a real impact in the average. Five above-average days in August could easily cancel out the below average days that we have experienced in the last week.
Just look at the graph from the National Oceanic and Atmospheric Administration (NOAA) and decide for yourself. Does it look like the trend from 1980 to now is up or down?
Since the graph clearly shows an upward trend since 1980, the next question is, why wouldn't it continue? What has changed in the last week that would reverse the trend? If you can't think of anything, well, I can't either.
Don't trust the data? Find some of your own! That is the problem with all the climate change deniers. They don't believe the data they are given, but they don't have any measurements of their own to contradict official data. Until they do, I'm using the only data that are available, and those data show a steady trend upwards.
NOAA also shows that through November (December data are still being collected) 2013 was the hottest year in recorded history.
So, given all that, that the climate has been warming since 1980, that 2008-2012 were among the hottest years ever recorded, and Jan-Nov 2013 was the hottest period ever recorded, what do you think the average temperature will be this year? Are you going to go with the last 5 days, or the trend for the last 5 years?
If you are going with the last 5 days, don't ever give me stock advice.