Friday, August 03, 2012 ... Français/Deutsch/Español/Česky/Japanese/Related posts from blogosphere

UAH, first 7 months: 2012 was 6th warmest

In July 2012, the UAH global temperature anomaly was 0.09 °C cooler than in June 2012, at 0.28 °C.

The June 2012 anomaly was, much like the July 2011 anomaly one year earlier, at 0.37 °C. This month-on-month cooling occurred despite the apparently emerging 2012-2013 El Niño.

This is the barchart of the average temperature in the first 7 months of the years 1979-2012.

You may see that 2012 had the 6th highest average. If you want the table, here it is:

  1. {1998, 0.53}
  2. {2010, 0.47}
  3. {2005, 0.25}
  4. {2002, 0.25}
  5. {2007, 0.23}
  6. {2012, 0.17}
  7. {2003, 0.15}
  8. {2006, 0.14}
  9. {2009, 0.13}
  10. {2011, 0.12}
  11. {1991, 0.11}
  12. {2004, 0.11}
  13. {2001, 0.07}
  14. {1988, 0.05}
  15. {1983, 0.02}
  16. {1995, 0.01}
  17. {1980, 0.00}
  18. {1987, 0.00}
  19. {1981, -0.02}
  20. {1999, -0.04}
  21. {1990, -0.06}
  22. {2000, -0.07}
  23. {1996, -0.12}
  24. {1997, -0.12}
  25. {1994, -0.13}
  26. {2008, -0.14}
  27. {1986, -0.20}
  28. {1979, -0.23}
  29. {1992, -0.24}
  30. {1982, -0.25}
  31. {1993, -0.27}
  32. {1989, -0.28}
  33. {1984, -0.29}
  34. {1985, -0.31}

Add to Digg this Add to reddit

snail feedback (6) :

reader David McMahon said...

Some trend over the last decade! I would say this makes people who go around saying its getting warmer and warmer complete liars. Its also interesting how the lunatics Romm, Hansen and McKibben go around saying recent weather events in the US prove their theory, but are we supposed to believe this wasn't the case in 1998 or 2010 when it was much warmer (and many areas enjoyed much snow in 2010).

reader David Nataf said...

The fact 2010 was warmer than 2012 does not support or refute any sensible argument. Same with 1998. You can't draw your conclusions from individual points, you have to look at the entire data series and even then your conclusions are limited at best.

The best-fit trend by the way is 1.26 +/- 0.30 degrees of warming per century.

That is statistically robust by the standards of fields outside of particle physics :-) but it's only one third to one half of the trend predicted by typical warming models, and it could be that the chosen time period is irrelevant.

reader David McMahon said...

I'm not drawing conclusions from a single data point, I'm referring to claims recently stated in the NYT and elsewhere that its getting hotter and hotter. No, its not. In any case the temperature has been flat for at a minimum a decade and likely 15-17 years - so its the conclusions of the alarmists that are "limited at best".

reader David Nataf said...

David McMahon,

From this data alone the trend is (1.26 +/- 0.30) degrees of warming per century. You'll get that from any software package. I just computed the least squares relation:

There is no statistical evidence for a higher order term. If you do put it in a second order term, you find that it's positive, implying an increasing warming trend. However, it's not significant.

reader David McMahon said...

David Nataf,
The warming stopped in 1998. It might resume of course, but until then we have to admit to ourselves the warming has stopped.

Secondly how do you determine how much warming is natural (some certainly due to end of "little ice age") and how much due to Co2? I suspect not much of the warming is due to Co2 (although I accept some is).

reader David Nataf said...

David McMahon,

It's not statistically valid to pick a point and say "the warming stopped there".

Even if you only include the years 1999-2012 as you're suggesting, which is not statistically valid because you have no reason to throw away the other data, you get a trend of (1.40 +/- 0.97) degrees of warming per century. The signal is weaker because you've removed half the data. That's 1.44 standard deviations, we have no idea if warming has stopped, continued at the same pace, or accelerated. However that's how it goes: very brief snapshots such as 14 years of data give very little information.

Second, from that data alone you cannot determine how much warming/cooling is natural. All that data gives you is the maximum likelihood rate of warming/cooling within that time period and the associated statistical error, nothing less and nothing more.