What was that about "hottest year"?

When scientists behave badly

Just last week, many news outlets announced 2014 was the hottest year on record. This was used to convince people global warming is real. However, not even a week later, the NASA scientist who made the statement then admitted that NASA is only 38% sure that this is true (note that this means they are 62% sure that it may not be the warmest year).  Wait. Aren't scientists supposed to be honest and give out accurate information? Yes, they are. Sadly, sometimes scientists do not follow that rule. This is one case. The 2014 was basically tied with 2010 and 2005 for hottest.

There is what is called a margin of error in these calculations. Figuring the global average temperature is not like measuring the temperature in your backyard. Thousands of numbers go into the equation and not all weather stations are located where hot buildings, etc. don't affect them. So the scientists "make adjustments" for these things, meaning they change the value based on what they believe the temperature would be without the buildings, etc. These adjustments and the sheer volume of data makes for a possibility of error in the final temperature reported. Even more complicated, climate science does not deal with actual temperatures, but the difference in the temperature calculated from a baseline. If by now you have realized just how complicated this is, you're on the right track.

Properly sited weather station

Reading will be too hot

Readings will be too hot

The pictures show the difference in placement of thermometers. Next to buildings, etc, will read hotter than the actual air temperature because of the heat coming off the pavement. This makes things look much hotter than they actually are. It also makes nighttime temperatures read higher because the pavement gives off

heat all night.

Then there's the leveling off of temperatures:

In spite of all the talk of "hottest" year ever, part of the problem is the last ten to 15 years have not really gotten much hotter. The difference is sometimes as small as .02 degrees. Considering how difficult it is to get accurate temperatures, the difference could just be due to the way we measure.

There are measurements made by satellites that cover the globe much better. These measurements show the average temperature of the earth is actually staying quite level.  

To get an idea of how this "hottest year", but not really, works, consider this example:

Your parents give you an allowance of $10 per week.

Four weeks ago, on your way home from school, you found a penny on the sidewalk, so that week you had $10.01.

Three weeks ago, you found two pennies on the sidewalk, so you had $10.02

Two weeks ago, you found no pennies, so you had $10.

Last week, you found three pennies on the sidewalk, so you had $10.03.

Now, we can truthfully say last week you had the most money so far. We can also say weeks four and three were above "average", if we consider the $10 the average. Do you really see the weeks you found the pennies on the sidewalk as being above average or that you were richer that week? The difference is very, very small indeed.

Here's another way to look at the "increase in temperatures" over the past century:  

This is what the average global temperature looks like, in degrees fahrenheit, when you graph the actual temperatures and not the difference from the average.  Also, the differences from the average (the anomalies) are graphed in tenths of a degree, making the differences look very large to anyone looking at the graph.

That's how the "hottest" years have been working. The difference is very tiny--tiny enough to mean we don't know which is the hottest year and it really doesn't matter because there is such a small difference.

The temperatures have leveled off for now. 

This is very good news.  Things are not getting hotter and hotter after all.

(Photos from NASA and Creative Commons, graph from suyts.wordpress.com)