Suddenly statistical significance is important to you? But the much closer statistically insignificant difference between "hottest years" doesn't matter to you at all?? DOUBLE STANDARDS? Do you realize when you are being inconsistent? Does it bother you?

You seem to have missed the part of my post where I AGREED WITH YOU. lol. Could your interpretations be any more self-serving?

The GISS rate of recorded warming since 2000 is almost double that of HadCRUT4. But you argue that since the margins of error overlap that we can't tell for certain? OK, I'm fine with adding a qualification, similar to the one the Met Office supplied when they announced 2014 had the highest numbers but because it was so close to other recent years they couldn't make a meaningful distinction. And that's how it should be: plain honesty; not misleading people like Nasa did. Funny how you can argue both sides when it suits you. Do you even notice?

Either way, you said GISS was in the "middle of the road." That's just flat out wrong. GISS is at the very top of the range.

Regarding Tamino, he makes it clear that the trend since 1970 is the same now as it was 15 years ago. However, he also made a false statement when he said temperatures from 2000-2015 show no signs of slowing down. In fact, GISS shows no significant warming trend since 2000. That's a pretty clear "sign" that warming may have slowed down. Facts are facts.

So now we're talking solely about the long term trend? But I thought Tamino was talking about the recent 15 year trend. What else could he possibly mean when he says: "since the turn of the millennium... global warming has continued and shows no sign of slowing down"?

Global warming clearly has slowed down since the turn of the millennium! The recent trend is nearly half the 1970 trend! There's been so little warming in recent years that we can't even rule out a cooling trend! Clearly Tamino mis-spoke, or perhaps he is in "activist" mode and trying to spin the facts. Either way, the facts are clear and I have no idea how you manage to deny them with a straight face. http://www.woodfortrees.org/pl...

To remind you, I spoke of GISS showing the greatest warming in the context of the last 15 years: "As far as a simple linear trend is concerned, it is unlikely that there has been no warming since the beginning of the century, based on GISS data. But it is not at all unlikely if you use any of the other data sets."

And your response is to pick a single trend to back up your false assertion that GISS is "in the middle of the road"? Wouldn't it be smarter to look at the whole data-set???

Do you even care that you are factually incorrect so often? Doesn't it bother you?

Wrong again.

"GISS dTs is not a land-only dataset but a land-ocean one extrapolated from land stations."

HadCRUT4 is warmer than GISS? Wrong again. Yes, the long term trends look similar from the late 60's to the early 80's, but then they diverge again. In fact nearly every other start-date shows GISS as warmer. GISS shows a trend from 2000 that is almost double that of HadCRUT4.

That's two glaring factual mistakes in one small post. Maybe check your facts next time. It's pretty clear you don't really know what you're talking about.

I did think we had cleared this up. There's a big 45 year trend line right there on his graph, and he shows how recent data (NOT the recent trend) fits in with the extrapolated 45 year trend. We can check this by comparing the ACTUAL trend from 1970-2015 with his extrapolated trend, and yes we see they are almost identical. But if we look at the recent 15 year trend we see that cooling has slowed down in recent years. His whole point is that this "slow-down" or "pause" has not effected the long-term trend.

Clear now?

Yes, and Tamino's method also shows cooling since 1950. http://www.woodfortrees.org/pl... That's because his extrapolation trick is bogus: it tells you very little about short term trends. If you want to make statements about short term trends, then you need to look at the short term trends. You said so yourself not so long ago, so I thought we agreed on this one. ("If you wanted to compare pre-1950 with post-1950 you would do this...") I'm not sure why you are being inconsistent on this.

It is correct to say there is no significant warming trend since 2000. And it is also correct to say that the recent "pause" does not effect the long-term trend since 1970. But it is incorrect to say that the warming since 2000 has continued and shows no signs of slowing down. For whatever reason "Hansen's Bulldog" decided to "spin" things. Perhaps he misspoke. I asked him but he hasn't published my comment. (Likely due to the spam filter.)

Up until now we were talking about global surface temperatures. But when you said GISS wasn't the hottest data-set you were talking about land-only temperatures? I admire your flexibility.

Do tell: how much hotter is BEST compared to GISS? Does GISS even have a "land-only" data-set??

What data-set shows more warming that GISS? (BEST is land-only.)

Cowtan & Way says the hottest data-set that's already been adjusted upwards to the tune of 2C in some cases has a "cooling bias"? You'll forgive me if I don't accept the conclusions from a single study. (Their paper has been torn to shreds by critics.)

Skeptics did not create these graphs, but here's another one which shows that global sea ice extent is not unusually low :
http://www.climate4you.com/ima...

As you can see from the above, global sea ice has recovered in recent years and is fairly close to what it was in the 80's. Maybe you should look before you leap.

Antarctic sea ice was at all time record highs for much of 2014, while Arctic sea ice hit a record low in 2012. Overall they pretty much cancel each other out.

(And shouldn't your graph look more like this?? http://woodfortrees.org/plot/n... )

As far as a simple linear trend is concerned, it is unlikely that there has been no warming since the beginning of the century, based on GISS data. But it is not at all unlikely if you use any of the other data sets. (GISS is an outlier. Maybe it has to do with the +2degC of warming they are known to add via adjustments.)

As for sea ice, it's about average. http://arctic.atmos.uiuc.edu/c...

Antarctic sea ice was at record highs until just recently: http://nsidc.org/data/seaice_i...

And finally, the properties of CO2 do not change, but only a small portion of the predicted warming is due to CO2 directly. MOST of the predicted warming is due to "climate sensitivity" estimates, which are all over the map. Climate scientists claim that the climate reacts to the heating caused by CO2 by amplifying it 3 times. (The range is much wider. I've seen climate sensitivity estimates as low as 0.9C and as high as 7 or 8C.) However, there is little evidence to support high climate sensitivity estimates and the uncertainty in this area is vast. If the climate is not as sensitive to CO2 heating as scientists have assumed, then global warming is not a serious threat.

Regardless, like many other skeptics I actively support innovative nuclear designs and fusion projects, since fossil fuels are expensive, dirty and finite. If AGW proponents weren't allergic to the word "nuclear" then the AGW scare might serve a useful purpose. Unfortunately the pro-AGW crowd will likely continue to impede the only viable solution to their non-existent problem: nuclear.

Yeah, I saw that which is why I didn't specify what the trend-line signified. Whether he's using the 45 year extrapolated trend-line or the actual 45 year trend-line makes little difference, since they're practically identical. (That's the whole point of his post.) Either way he is showing how the recent data fits with a 45 year trend-line "just about as closely as one could have imagined".

This: http://www.woodfortrees.org/pl...

Not this: http://www.woodfortrees.org/pl...

Why not. I'll go into a little more detail since this isn't clear to you for some reason.

Tamino says: "Assuming global warming continues without slowing down, we would have expected this," with an accompanying graph that extrapolates the long-term trend from 1970.

Then he says: "This is what actually happened," with an accompanying graph clearly showing a long term trend-line from 1970-2015. The point is clear: the recent pause has not affected the long term trend.

He says the recent data fits the long term trend "just about as closely as one could have imagined." He can only be comparing the two long term trends since the recent 15 year trend is less than half that of the previous 30 years. Far from a fit that's as close as "one could have imagined".

Where does he specify how he came up with these graphs and trend-lines? He talks about "the global-warming-continues-without-slowing-down pattern", but that's about as technical as he gets. Most of the post is just a rant.

The title of his blog post is "It's the Trend, Stupid". The whole point of the post is to show how the "pause" hasn't affected the 45 year trend; that it's practically the same as the 30 year trend from 1970-2000.

At the end of the post he writes: "They just don’t seem to realize that the real embarrassment to their precious “pause” is the trend." Again, he is contrasting the 15 year "pause" to the long term, 45 year trend.

In the comments section Zeke Hausfather of Yale Climate Connections says "Looks like we both had the same idea; I made a very similar figure over the weekend for Yale Climate Connections" On the referred Climate Connections post Zeke writes: "While the trend over the past decade is fairly flat, there is a danger in over-interpreting short-term trends in long and noisy time series, as this illustration shows." It's the same theme: the recent pause doesn't effect the 45 year trend.

His illustration looks just like Tamino's and Gavin's: https://i0.wp.com/www.yaleclim... It clearly shows a trend-line from 1970 to 1999 and a trend-line from 1970 to 2015. It does not show a recent trend-line which would look "fairly flat", as he acknowledges above.

Gavin Schmidt's graph, Tamino's graph and Zek Hausfather's graph all look like this: http://www.woodfortrees.org/pl...

None of their graphs look like this: http://www.woodfortrees.org/pl...

Does that help clarify things?

Perhaps you are in denial. I think Nasa's Gavin Schmidt is better positioned to understand what Tamino has done than you are. On the RealClimate site Nasa's Gavin Schmidt is doing exactly what Tamino is doing, and Schmidt says as much: "Tamino has a good post on this as well".

It's not a coincidence their graphs look a) similar to each other; b) similar to this: http://www.woodfortrees.org/pl... and c) not at all similar to this: http://www.woodfortrees.org/pl...

It's too bad Tamino does not say explicitly what his graph represents. It was obvious to me from the start, but I guess it's not obvious to everybody. It would have saved you some time if he had.

Ciao.

No, he did not compare the 1970-2000 trend with the 2000-2015 trend. That is where YOU are confused. From the RealClimate site: "the underlying long-term trend has not changed appreciably over the last decade or so. (Tamino has a good post on this as well)... 2014 is almost exactly on trend extrapolating from 1970-2013 or 1970-1998".

http://www.realclimate.org/ima...

Lol! That's what I've been saying all along! If you wanted to compare pre 2000 with post 2000 you would do this: http://www.woodfortrees.org/pl...

Suddenly you prefer that approach to Tamino's extrapolation trick? Care to explain why it's legitimate in one case but not another?

Tamino's method shows global warming is slowing down when it should be speeding up:

http://www.woodfortrees.org/pl...

Lol

Lets use Tamino's extrapolation trick to determine if AGW is real. According to the IPCC, anthropogenic CO2 started to have a real influence on temperatures since 1950. (Prior to that the anthropogenic contribution of CO2 was too small to have had much of an influence.) We will do what Tamino did: we'll take the trend from 1900-1950 and extrapolate it, then compare the extrapolation to the actual trend from 1900-2015. If the world was warming because of human influence, we should see a noticeable increase in the trend from 1900-2015 compared to 1900-1950.

http://www.woodfortrees.org/pl...

!

You seem to think that "no significant trend" is not a legitimate answer for some reason. Interesting. Maybe what you mean to say is that "I have chosen a method that is not giving me the answer I want."

So let me put it in terms you might be better able to understand. If the data showed an increased warming trend since 2000, Tamino's extrapolation trick is the one skeptics would be using to try to "prove" that global warming has "stayed about the same". AGW proponents would laugh themselves silly at such a feeble attempt to mask the temperature increase. Yet bizarrely here they are doing what they would surely condemn if it was done by others.