Merged Global Warming Discussion II: Heated Conversation

[Trakar]

I'm a Brit, we know about weather . It's a basic survival skill.

LOL, GB and the PNW have a lot in common, at least weather-wise.

 

[balrog666]

Failed predictions disprove AGW?

Failed predictions disprove prediction methods and nothing more.

 

[Fizil]

Have the observations consistently fallen well outside the error bars of the predictions? If they have then people might have a point that the models are wrong, if they haven't then claiming that the predictions were "wrong" is itself invalid, since the predictions are not exact numbers, but inexact ranges. And an observation can fall outside the predicted range, even with errors, since those error bars merely give the range of high confidence. It is possible that even if you are 95% sure that a predicted value will fall between 1-2, you might observe 3 or 0. It would only be if observations consistently fell outside the error bars of a model's predictions that you have a problem.

 

[Trakar]

Technically these are projections rather than predictions, but they seem to exist within the projected ranges pretty closely.

IPCC AR5 Figure 1.4. Solid lines and squares represent measured average global surface temperature changes by NASA (blue), NOAA (yellow), and the UK Hadley Centre (green). The colored shading shows the projected range of surface warming in the IPCC First Assessment Report (FAR; yellow), Second (SAR; green), Third (TAR; blue), and Fourth (AR4; red).

The latest on Climate change predictions can be found in the newly released AR5 (pdf downloads)

Near-term Climate Change: Projections and Predictability 14.1MB
##Long-term Climate Change: Projections, Commitments and Irreversibility 36.3MB

 

[riptor]

Thanks for the responses everyone. I think the main point this person was getting at is that since the observed temperature increase didn't match the projections, it is disingenuous of scientists to attempt to explain why their projections were off.

 

[lomiller]

I know there has been some discussion recently on how to handle global warming threads, and I did do a search but couldn't really find what I was looking for. Some of the threads on the subject are huge.

An argument against AGW that I've been encountering a good deal lately is that since scientists and organizations that study climate change have made predictions that were wrong in the past, that this somehow disproves AGW. Specifically, since the warming hasn't increased as much as previously predicted this means that any further attempts by the science community to investigate why the predictions didn't happen as previously thought, are nothing more than excuses to bolster a failed theory. In one online discussion one person listed such "excuses", which included low solar activity, aerosols, stratospheric water vapor, wind, and others.

So the question is when does it become just making excuses for a failed theory?

In such cases what you usually have are blog that are deliberately misrepresenting the actual predication then attacking the misrepresentation rather than the real prediction.

For example, they will do things like take the predicted warming trend of 0.15 - 0.2 deg C per decade, and draw that trend starting from the late 90's.

The trick here is that the late 90's were actually MUCH warmer than the actual predictions. A full 2 sigma in 1998. By starting the line at this point they ensure that the measured temperatures all fall well below it. What they don't tell you is that the the line they just drew is actually more that 0.2 deg C warmer than the actual prediction.

 

[CapelDodger]

Have the observations consistently fallen well outside the error bars of the predictions? If they have then people might have a point that the models are wrong, if they haven't then claiming that the predictions were "wrong" is itself invalid, since the predictions are not exact numbers, but inexact ranges. And an observation can fall outside the predicted range, even with errors, since those error bars merely give the range of high confidence. It is possible that even if you are 95% sure that a predicted value will fall between 1-2, you might observe 3 or 0. It would only be if observations consistently fell outside the error bars of a model's predictions that you have a problem.

Indeed, and they haven't. Which, given that ENSO activity has been far from average during this century, suggest that the variances about the mean were well estimated.

Reality has dipped close to the lower error bar, but this is not surprising given the La Ninas, some extra aerosols, and low solar activity all acting in the same sense is not surprising. In fact it's remarkable that it hasn't fallen outside the error bars given that combination.

Now there are signs of an El Nino, and even without one there's no reason to think we won't get another warm year. Deniers are dependent on La Nina, and I think they're coming to realise it.

When the PDO does shift and the mythical Pause is replaced by a mythical Acceleration, deniers are going to find they've nailed themselves to surface temperatures and short-term trends so firmly they'll never wriggle free. Not while I'm still kicking, anyway .

 

[CapelDodger]

Thanks for the responses everyone. I think the main point this person was getting at is that since the observed temperature increase didn't match the projections, it is disingenuous of scientists to attempt to explain why their projections were off.

It's a strange way of thought, but you're probably right. He wants the projections to be wrong because there's no AGW, which he really wants there not to be. What he doesn't want is for someone to explain why reality came out at the lower end of projections up to now; in fact he believes they have completely failed the reality check. A trusted source told him so, and anyway everybody knows it. Cognitive dissonance at work.

Deniers will always set impossible demands of accuracy while ignoring the only perfectly accurate model there is - the big bad analogue model we call home. Shame we can't make it run faster than real-time, but the tech guys say there are issues with that. Whatever, it's never been wrong yet.

 

[Trakar]

http://data.giss.nasa.gov/gistemp/maps/
http://www.ncdc.noaa.gov/cag/

On the second graph, try clicking the little box that adds a trend line to the graphs and see what they actually indicate. (BTW very minute portions of the Boreal exist within the US). With regards to the first site, looking only at the temperature in one month in 2014 there is little surprise that you see cold - note "begin - end" time. If we adjust the begin time to 1901, 1985, 1998, 2005, or even 2011, we see a very different pictures which seems to indicate that warming has continued pretty much continuously over the last 100 years or so. There is a little lack of warming in north central Asia locality for a few years but not something I'd quantify as either widespread or even regionally extensive, yet alone something that would significantly impact hemispheric means. even less so if we use the same dates and expand the range to include "Late Fall - early spring" Nov. - April "NH cold season" (which an expanding and growing winter cold would presumably expand into).

 

[CapelDodger]

The trick here is that the late 90's were actually MUCH warmer than the actual predictions. A full 2 sigma in 1998.

The Surge before the Pause, I remember it well .

Of course in 1998 the deniers were full of it being El Nino, nothing to see here, the models have failed, yadda yadda. In 2005 the El Nino riff was dropped as we first heard "no warming for seven years". Who knew it would reach 17?

Now the more careful deniers are saying 16 or even 15 (while US Congressmen say twenty) years without statistically signficant warming. What kind of Pause gets shorter as time passes?

 

[macdoc]

One of the biggest issues with claiming the "predictions" were wrong stands on the reality that there is no way to predict how much fossil fuel will be burned by humans.

For instance the US had 11% lower emissions last year due to a shift in power generation to natural gas.

ALL projections can only make assumptions about CO2 emissions and hence their impact on the climate.

AGW Deniers a noisy but dying breed. Time to move on to solutions which are a very difficult topic.

 

[Trakar]

The Surge before the Pause, I remember it well .

Of course in 1998 the deniers were full of it being El Nino, nothing to see here, the models have failed, yadda yadda. In 2005 the El Nino riff was dropped as we first heard "no warming for seven years". Who knew it would reach 17?

Now the more careful deniers are saying 16 or even 15 (while US Congressmen say twenty) years without statistically signficant warming. What kind of Pause gets shorter as time passes?

Well, and the key point is that it hasn't been a "pause," merely a slowed rate of increase. 2005 was warmer than 1998, the trend has continued, even though offsetting factors have reduced the rate over the last decade, or so.

Oh, and "some" US congressmen, there are even some Republicans who understand reality and generally respect and abide by its precepts, even if they don't much speak out in the current environment.

 

[a_unique_person]

Meanwhile, back in the real world.

The national commodities forecaster has released a map showing vast areas of key agricultural production land are suffering the driest soil conditions in 100 years.
The Australian Bureau of Agricultural and Resources Economics and Sciences (ABARES) annual conference began in Canberra today.
The map, produced under the Australian Water Availability Project, measures the upper layer soil moisture across the country as at January 2014 and compares those figures to the past 100 years.
It tells a poignant story with the majority of sheep and wheat producing land falling into the 10 driest months on record in that time.As well, much of the rest of the agricultural districts, including inland Queensland, the cattle regions of WA and NSW, inland South Australia and parts of Tasmania, are also among the driest in decades.

http://www.abc.net.au/news/2014-03-04/abares-opener/5295780

 

[macdoc]

Trakar

Well, and the key point is that it hasn't been a "pause," merely a slowed rate of increase. 2005 was warmer than 1998, the trend has continued, even though offsetting factors have reduced the rate over the last decade, or so.

and in reality no slowing at all if one takes ocean heat increase which accelerated and may well come back to haunt us this year if a major El Nino develops.

Stay tuned - interesting times.

 

[greybeard]

Trakar

and in reality no slowing at all if one takes ocean heat increase which accelerated and may well come back to haunt us this year if a major El Nino develops.

Stay tuned - interesting times.

The problem for those who deny the science IMO is that they have overdone the "no increase in surface temperatures since the last El Nino". We haven't seen a year below the 20th century mean since 1976. How are they going to explain another steep rise in surface temperatures? With solar output declining how do they explain where this extra heat is coming from?
Maybe they will fall back on it being badly sited temperature monitoring stations again.

 

[uke2se]

The problem for those who deny the science IMO is that they have overdone the "no increase in surface temperatures since the last El Nino". We haven't seen a year below the 20th century mean since 1976. How are they going to explain another steep rise in surface temperatures? With solar output declining how do they explain where this extra heat is coming from?
Maybe they will fall back on it being badly sited temperature monitoring stations again.

Probably sun spots or magic solar rays. After all, the sun is apparently the cause of warming whether it's activity is going up or down.

 

[Trakar]

Trakar

and in reality no slowing at all if one takes ocean heat increase which accelerated and may well come back to haunt us this year if a major El Nino develops.

Stay tuned - interesting times.

True, if nothing else, we should get in the habit of clarifying, that the rate slow down only applies to Surface Temperatures which are not expected to track perfectly with ghg induced increases, at least in the short-term, due to so many natural buffer systems (the oceans being a large such factor).

 

[Trakar]

One of the biggest issues with claiming the "predictions" were wrong stands on the reality that there is no way to predict how much fossil fuel will be burned by humans.

For instance the US had 11% lower emissions last year due to a shift in power generation to natural gas.

ALL projections can only make assumptions about CO2 emissions and hence their impact on the climate.

AGW Deniers a noisy but dying breed. Time to move on to solutions which are a very difficult topic.

The problem with discussing public policy options (which most resolutions require in one form or another) is in maintaining an overwhelming voting majority among a largely scientifically ignorant population, which isn't just accepting of the general principles of AGW, but that also recognize the future dangers associated with the consequences of AGW. That is a long tough row to hoe, as there is a big step between AGW and the more dire consequences of AGW, this is considered an unsettled issue even among many AGW supporters within the scientific community. Public policy action has a much higher critical mass than AGW science acceptance.

 

[Trakar]

Here's a paper more recent than Cohen et al. 2012, which is addressing the same question:

Juan C. Jiménez-Muñoz, José A. Sobrino & Cristian Mattar (July 2013). "Has the Northern Hemisphere been warming or cooling during the boreal winter of the last few decades?" Global and Planetary Change, vol. 106, p. 31–38 (link).

Fair use quotes:

near the end of the conclusions where they are addressing the questions posed earlier in the document, we also find them clarifying the "period of cooling" identified:

Values of trends and its significance are dependent on the time period considered (and also on the record length). This is an expected and well-known result, and it is clearly illustrated in the differences observed in the periods 1980–2012, 1988–2010 and 1981–2003 (Fig. 4, Fig. 5 and Fig. 6, respectively), but also on the evolution of the trend (and its significance) when the start year or end year of the time period is shifted (Fig. 7).

Again, a rather common variable that has more to do with statistical analysis than actual surface temperatures.

 

[CapelDodger]

The problem for those who deny the science IMO is that they have overdone the "no increase in surface temperatures since the last El Nino".

A tactical blunder, but these people are not the brightest and the best so no surprise there. Pat Michaels, a well-known US American professional perjuror, has actually advised against it publicly but to no avail. Deniers simply cannot resist a short-term expedient.

We haven't seen a year below the 20th century mean since 1976. How are they going to explain another steep rise in surface temperatures? With solar output declining how do they explain where this extra heat is coming from?

Solve the problem at source - deny there's any extra heat and blame the appearance of it on a cabal of climate scientists who control all the temperature readings. That buys them another few years. After that ?I'm with uke2se, it'll be cosmic rays.

They can deny they ever said there was a Pause, hiatus, slowdown or cooling. What's more they can believe they never said it.

Maybe they will fall back on it being badly sited temperature monitoring stations again.

There's a drinking game in this, isn't there?