How are climate anomalies computed?

1 Answer
Mar 28, 2017

Climate doesn't have anomalies.

Explanation:

Climate is the weather that is expected over an area, and it is a long term expectation. Since it is long term, any changes also have to be long term. A particularly warm day in Greenland or snow in the Caribbean are not climate. These short term meteorological occurrences do not change the climate.

When we talk about climate change then, we are talking about an over all trend of warming or cooling or a trend in the humidity regime. When you look at climate there are no "anomalies", because if it is a long term change it is by definition not an anomaly, and if it is a short term change it simple does not impact on the data.

For example, if an area was 5 degrees warm for 5 days straight, if we are looking at the average yearly temperature that would affect the yearly temperature average by less than 0.1 degrees per day. That does not take into account the rest of the year when there maybe a cold spell which would even things out.