Global Warming Test

[KennyTew2]

What is the point of this video? Are we supposed to conclude that the local trends and variations in Alabama somehow trump the well established global trends, or that global cliimate is a complicated subject with many local variations which might, to the uneducated at least, make it seem like local trends prove global patterns wrong.

The logis is thus, my household income grew for each of the quaters of the recent recession, therefore the UK recession didn't happen.

[david222444]

Conclusion the temperatures in Alabama are cooling.

[aztecking21122012]

Your stats are good and well presented and I accept your facts. However you displayed a graph at the end in which you said it trended downward. Not true. Your gragh has no trend but has three distinct patterns. This gives the same result, but if you don't want to be corrected.......you might want to change that last part.

[Spectre11B]

Statistically you would never use data from extremes to establish a trend. This is poor mathematics. You would also never use a state as a sample size for the entire world.

Things like pressure, elevation, angle etc will affect temperature. For example, a temperature increase on one side of a mountain range will cause a high pressure zone to form, which may cause a decrease in temperature on the other side of that range as rapid air flow moves through it.

[anoniab]

The question you need to ask is does your furnace and A/C operate according to the global average or to actual temps. I don't believe the global average means anything. Temps are all local.

[pozzolane]

Spectre11B: "Statistically you would never use data from extremes to establish a trend."

Curious. Since this is exactly how they calculate average daily temps (by adding the daytime high and low and then dividing the sum by 2), which they use for calculating yearly average temperatures...

[Spectre11B]

Let's look at your logic. If the daily temperature was 100 degrees for 11 hours, and the temperature dropped 50 degrees for one hour, according to your statement, the average temp for that day would be 75 degrees.

Considering the temperature was 100 degrees for almost the entire day, does 75 degrees, in your opinion, accurately represent the average temperature for that day?

[Spectre11B]

replace 11 hours with 23 hours.

[pozzolane]

Of course it doesn't. That was my point.

[Spectre11B]

Well then, I misunderstood your point then.

Normally, when establishing trend lines, you remove data which would fall outside of the normal regression line, called outliers.

While any data that falls in the extreme range have a value on their own, trend lines are used to make predictions. Since it's beyond the capability of a trend line to predict anomalies, outliers are generally removed from the data set.