Has BBC Reached the Global Warming Tipping Point?

[Redbelly98]

Again, once more, maybe the essence is that Trenberth acknowledges no warming:

... we can't account for the lack of warming at the moment ...

would that depend on any starting year?

Certainly. GW is a long-term effect. To acknowledge that there is no warming at the moment, or even over the past few years, says nothing about the long term warming trend that we are in.

 

[Andre]

Paul must therefore be using HadCRUT3, which is fair enough for a BBC writer, as this is from the UK met office. The linear trend for the last eleven years does show a small increase -- even if you start in 1998! The regression gives 0.032 C/decade.

If you do the estimate with the GISS dataset, then you get a warming trend over 1998 through 2008 of 0.115 C/decade.

For completeness, not for disputing, the trends of the satellite data between Jan 1998 and November 2009 seem to be (in degrees K per decade), http://www.remss.com/data/msu/monthly_time_series/RSS_Monthly_MSU_AMSU_Channel_TLT_Anomalies_Land_and_Ocean_v03_2.txt

But it will still be interesting to see what happens to the trend if ALL perceived effects of the ENSO would be removed, thinking especially of the La Nina dip immediately after the 1998 El Nino maximum.

 

[sylas]

For completeness, not for disputing, the trends of the satellite data between Jan 1998 and November 2009 seem to be (in degrees K per decade), http://www.remss.com/data/msu/monthly_time_series/RSS_Monthly_MSU_AMSU_Channel_TLT_Anomalies_Land_and_Ocean_v03_2.txt

That sounds about right... and of course, these numbers are equally meaningless as indicators of long term trend, just like the surface temperature. They are figures for the atmosphere, and the uncertainty limits are even larger than at the surface. I have not attempted to estimate confidence limits for them myself as yet, however.

It's still useful data; because the short term variations are real and something we'd like to understand also!

One thing I find interesting is that the Large El Nino spike in 1998 is larger in the atmospheric data (lower troposphere) than at the surface. Your links are to atmospheric datasets. Even allowing for the larger errors in atmospheric measurements, this is still interesting and may be a clue to the processes involved. I don't know.

But it will still be interesting to see what happens to the trend if ALL perceived effects of the ENSO would be removed, thinking especially of the La Nina dip immediately after the 1998 El Nino maximum.

I agree! There have been attempts to do this kind of thing, using statistical arguments and the southern oscillation index.

I think Trenberth is right. What we REALLY want is better data, so that we can figure out precisely where the energy goes during these ENSO variations. I like statistics, but scientifically I find argument based on correlations to be very unsatisfying. I want to know the physics. To test models for the physics of how temperature is actually changing, we need to track the energy flows. Then we'll have a much better way of identifying and removing the ENSO effect.

Cheers -- sylas

 

[DrClapeyron]

12 out of the 40 threads on the first page of P&WA are about global warming (email scandal, cap and trade, investing confidence in climate experts, etc).

One tipping point seems to be that all Republicans in the US oppose climate change bills while Democrats support climate change bills, but at the same time no significant pieces of legislation have resulted in the 20 some odd years of the global warming debate.

 

[Andre]

12 out of the 40 threads on the first page of P&WA are about global warming (email scandal, cap and trade, investing confidence in climate experts, etc).

One tipping point seems to be that all Republicans in the US oppose climate change bills while Democrats support climate change bills, but at the same time no significant pieces of legislation have resulted in the 20 some odd years of the global warming debate.

And there is your problem. It's politics and nobody can't affort to be wrong.

Eventually nature will tell who is wrong and nature is not democratic, I'm afraid.