The reason is that you are less sensitive to which thermometers you use. Suppose you had a whole bunch of extra thermometers in cold places, and then a large number of them were taken off line. Suddenly it would look like the world has warmed, because you removed thermometers from cold places, the average has gone up. By using anomalies, you then remove that problem. This is not a random issue, the dying of the thermometers actually happened.
Simplified: Anomalies are zonal regional occurrences that can have different ranges based on occurrence. Raw data is what you get and averaged for a simplified trend.
In a nutshell another way of expressing the extreme/means. Theoretically both should equal each other. Part of the whole climate argument.
It's not better to measure climate that way, it's just a different way of looking at it. If we wanted to know whether one city was hotter than another we wouldn't use anomalies, we'd use the actual values.
Anomalies are good when we want to compare two things with different mean values. For example, by comparing anomalies, it becomes easy to see that under global warming temperatures in the arctic have risen more than temperatures in the tropics--that's not as obvious when looking at the actual temperatures.
Because it lets you compare apples to apples.
If you compare day and night, summer and winter, or tropic and polar temperatures, the inherent differences between those would obscure any change, since the change is a matter of (as of yet) less than a degree, while the differences are a matter of, at a minimum, 10 or so degrees. But if you look at the anomaly--the difference from the local and/or temporal average--you can have similar numbers to look at.
Same reason it's a good idea to measure one's IQ by the size of their skull like they used to in the 1st part of the 20th century.
Because they can be manipulated easier. You can cook the books easier and thus create panic, which is the main objective of the 'saviors of the earth'.
Thank you! :)
