RSS AMSU, Jan-Sep: 2011 second coldest in this century

This text is just a tiny update of what I wrote one month ago and two months ago. The results are almost unchanged. The La Niña odds have considerably strengthened. The ranking according to RSS AMSU is significantly different from the ranking according to UAH AMSU I published in the morning: the two teams began to deviate and our skeptic friends at UAH AMSU show a warming trend while RSS AMSU shows a cooling trend in the last decade.

According to RSS AMSU, the first 9 months were the 2nd coldest January-September period in this century so far (second among 11 candidate years).




The top 15 ranking of the years 1979-2011 according to the average temperature during the first nine months is as follows:

1. 1998: 0.626
2. 2010: 0.542
3. 2002: 0.356
4. 2005: 0.349
5. 2007: 0.304
6. 2003: 0.296
7. 2001: 0.223
8. 2006: 0.220
9. 2004: 0.210
10. 2009: 0.209
11. 1995: 0.172
12. 2011: 0.171
13. 1991: 0.147
14. 1988: 0.124
15. 1999: 0.109

You can see that the first nine months of 2011 were colder than the same period of 1995 which was 16 years earlier; and of course, 1998 remains the leader of the league: its first 9 months were about 0.45 °C warmer than the same months of 2011. At the 12th position, 2011 is out of top ten. Only Jan-Sep 2008 with +0.009 °C managed to be colder than the same period of 2011 among the years of the 21st century. So 2011 is helping to make the preliminary 21st century RSS AMSU temperature trend even more negative than before; this is no bulšit, angry Al.

Some warming may have been taking place in recent months – because of the delayed effect of the disappearing La Niña a few months ago. But it may be replaced by another cooling in the coming months.

The ENSO oscillations have returned to the negative, La Niña territory after a few months in the neutral interval. For example, the latest weekly ENSO report says that the ONI 3.4 anomaly is at –0.7 °C (and the 1+2 region is also at –0.7 °C) – it went down from –0.4 °C two months ago and has slipped below –0.5 °C, the boundary of the La Niña conditions, again.

Some of their models used to show that there were equal odds that we will see neutral conditions in the Fall – but the following update, just like predicted, already indicated another La Niña episode for the winter 2011/2012, in agreement with NOAA press releases that were fresh a month ago. In fact, the picture from Monday shows a nice blue spot near the South American Western beaches:



I think that the blue spot sits at an important place – and is already big enough – and could help to decide that La Niña conditions will return on a more permanent basis. Just to be sure, that would be the second consecutive La Niña episode.

Whatever will happen to ENSO in the Fall, I think that it will only substantially influence the global temperatures in 2012. In the rest of 2011, we will see comparable temperature anomalies as in the first half of 2011 which may be smaller than the anomalies from July and August. That will mean that 2011 may slightly jump from the 12th warmest place (preliminary ranking), perhaps to a spot in the top ten, or drop slightly – but it will surely not get to the medal places for the warmest years. My best estimate says that 2011 will end up being 10th or 11th warmest year on the RSS AMSU record – considerably different from the 5th-9th ranking using UAH AMSU figures. (The RSS AMSU ranking for 2011 has a nonzero chance to jump to the 8th or 9th place, too.)

My prediction for the whole annual averages looks like this:

1. 1998: 0.550
2. 2010: 0.476
3. 2005: 0.334
4. 2003: 0.324
5. 2002: 0.316
6. 2007: 0.262
7. 2001: 0.245
8. 2006: 0.232
9. 2009: 0.226
10. 2004: 0.209
11. 2011: 0.198 ± 0.03
12. 1995: 0.159
13. 1999: 0.103
14. 1997: 0.102
15. 1987: 0.099

It's more likely than not at during 2012 or at the beginning of 2013, we will actually see an RSS climate record that will display a cooling trend during the most recent 15 years – partly because of the expected 2011/2012 La Niña, partly because the warm 1998 year will emerge at the beginning of the 15-year interval. Recent years increasingly paint the story that the "global warming" stopped more than a decade ago.

The first 11 years of this century surely display a cooling trend. One may believe that during the century (e.g. in 2040), the sign of the slope will be reverted but it doesn't have to be. There doesn't exist any convincing scientific evidence that it has to.