EM- The GISS publication is a good example. Most of the major forcings are listed. Some are not, such as the solar effects other than TSI, which we know is fairly minor. The UV content does change a great deal and we know it influences ozone, which is another forcing that is listed. Then we have the solar wind, but admittedly, the solar effects are not yet proven, but are suspect.

Not mentioned are the feedbacks. These are not trivial. Feedbacks are changes within the system which may have been triggered by forcings.

I always think that there is a third category, long term and very short term feedbacks where the timescale is such that the causal link with forcing is not obvious or outside of model capability. Many ocean temperature changes fall into this category.

Also difficult to predict are very short term changes such as thunder storms, rain storms and the like, which are local and fast forming. The transport of water vapour to high altitude followed by condensation due to lower temperature and resulting in latent heat being released and lost to space is a major cooling mechanism that cannot be simulated in current models.

These feedbacks act on our climate in different ways. The long term ocean changes can introduce significant warming in the manner of a forcing, making attribution difficult. This is probably the explanation of the warming last century.

The short term water cycle can act as a negative feedback to create the divergence between radiative forcing models and reality.

The GISS article is fine, but we must not regard it as the definitive text book. After all, GISS science is the invention of the man who brought us global warming and the prediction that New York City would be submerged under water by the year 2018. The waters around Manhattan are currently reducing in level.

Clearly, GISS assumptions are fundamentally flawed.

http://notrickszone.com/2017/11/13/new-agu-presentation-no-increase-in-earths-surface-temperature-from-increase-in-co2/

"At next month’s American Geophysical Union (AGU) Fall Meeting in New Orleans (US), an independent researcher named Trevor Underwood will be presenting an equation-rich analysis that thoughtfully undermines the perspective that increases in CO2 concentrations are a fundamental variable affecting climate.

Instead, Underwood argues that the absorption band where CO2 emissivity could have an effect is likely already saturated, precluding the capacity of increased CO2 concentrations to produce atmospheric warming.

He also advances the position that solar irradiance changes can explain modern temperature variations, which is consistent with other recent analyses."

Ravishing One. Consider your 10.49pm post as a "forcing" and this response to be a rather weak "feedback", but is it positive or negative. I be like a cloud.

I be like a cloud.

Nov 14, 2017 at 8:11 AM | Supertroll

Have you noticed any variation in your moisture content, and average spread?

Gwen. You can't be Cirrus; I spissatus at your "humor"

Supertroll, I had always wondered what those mare's tails and mackerel scales were!

I confess that I don't like the term "forcing". Many trades tend to have their own traditional technical words and these tend to be as old as the the origin of the craft. Climatology has only existed for a few decades and one would have thought that modern science has ample vocabulary to satisfy its needs.

Multidecadal oscillations can remain in a particular phase for thirty years, then flip, causing an apparent change in climate. What should we call this? Is it caused ultimately by the rotation of the earth, making it a feedback?

It is certainly a change. But no matter, alarmists will usually claim AGW if it results in more warming. In fact as GS of GISS points out, all warming is due to carbon dioxide.

Schrodinger's Cat, with all these extra "forcings" found by Climate Science, there must be extra "balancings" not yet found by Climate Scientists, to explain why the models are wrong.

Or the "forcings" are not as reliable and forceful as claimed.

President Obama fell for the faked up forcing of the 97% Consensus. It contained no science at all.

I don't like the concept of forcing either. The idea that there's some kind of ideal state around which a number of forcings operate and they can (apparently) be summed arithmetically as if they didn't interact seems a bit of a stretch to me. It's more of a way to sell AGW to the public. The Forcing can have a strong influence on the weak-minded.

I may be wrong, but I think the key point about a forcing is that it is external to the system such as a change in TSI or injection of CO2 or change in orbit. A feedback is a response and is an internal change.

It was with these definitions in mind that I questioned how to classify ocean changes that may change every 30 years. They are internal, yes. Feedbacks? They are periodic oscillations possibly due to currents, winds, tides and ultimately the earth rotating. But the resulting warming or cooling may be of the same magnitude as an injection of CO2. Are the causes I listed then equivalent to forcings? I doubt it.

There are many aspects of climate science that need improvement.

Supertroll - I hadn't realised that Keith Briffa had died. I understand he was quite troubled by all the climategate stuff. CRU was set up by Lamb to look at natural variability. He quite rightly believed that climate scientists should understand the basics and the extent of natural drivers before they started looking at human influences. They probably did start that work. Fairly soon after that the GHG bandwagon started to roll and everyone switched to that. When you think about it, it was alarmism that got the funding, not showing that some of the warming was natural.

Years ago, when I began to realise that climate scientists didn't understand the basics I was quite shocked. I couldn't believe it. I asked Judith Curry if it was true and she confirmed it. Today the models seem to be GCMs with CO2 radiative forcing and a few assumptions about aerosols, clouds, and water vapour feedbacks.
They don't understand most of these and can't model them so these are values they can tweak.

What has COP23 achieved? Still no science.

https://wattsupwiththat.com/2017/11/15/avalanches-of-global-warming-alarmism-at-cop23/

"One prediction stated: “The IPCC recently reported that temperatures will significantly increase in the Sahel and Southern African regions, rainfall will significantly decrease, and tropical storms will become more frequent and intense, with a projected 20 per cent increase in cyclone activity.”

To make such dire forecasts, the IPCC relies on computerized models built on data and formulas to represent atmospheric conditions, and reflect the hypothesis that carbon dioxide is the principal factor driving planetary warming and climate change.

However, we still do not have a comprehensive, workable “theory of climate,” and thus do not have valid formulas to properly represent how the atmosphere functions. We also lack data to properly understand what weather was like over most of the planet even in the recent past. Without a good understanding of past weather conditions, we have no way to know the history, or the future, of average weather conditions – what we call the climate."

https://wattsupwiththat.com/2017/11/15/new-map-of-antarctic-geothermal-heat-suggests-steig-mann-2009-werent-measuring-global-warming/

"This is quite interesting. Remember the claim in on the front cover ofNature in 2009 by Steig and Mann that Antarctica was warming, thanks to that “special Mannian PCA math sauce” that was applied to air temperature data to smear surface temperature trends over the entire continent? It was dashed by climate skeptics who wrote a paper. It was accepted for publication and disproved (in my opinion) by a team of credible skeptics that wrote a counter-paper. But, there’s an interesting twist thanks to new and surprising data; Steig and Mann may have captured surface air temperature trends in the exact same areas that have been identified as geothermal hot spots.

First the press release, from the British Antarctic Survey on Nov 13th, 2017: "

http://notrickszone.com/2017/11/16/scientists-affirm-that-no-the-arctic-is-not-melting-as-nothing-has-changed-since-1900/#sthash.WtaaDdBs.dpbs

"The answer to the second question is that the theory of global warming is completely disconnected from the observations since their definition of temperature is based on some theoretical number that has nothing to do with the temperature that is measured by calibrated thermometer and, most importantly, used as an international standard by the scientific community. Since the theory is clearly wrong about forecasting the temperature patterns in the Arctic, all other predictions made by the theory must be wrong too"

gc - The various papers you report on that appear at NTZ and elsewhere are building up a fairly substantial archive of publications that question or reject some or all of the AGW story.

This demonstrates that the science is not settled. It also shows that those at the centre of AGW seem to have reduced control over what can be published by the Journals. A recent post at WUWT shows that pal review is still a blight on the science, however, the rapidly increasing number of sceptical papers is a welcome sign that the scientific challenge is at long last catching up with climate science.

Hmmmm.

Nov 17, 2017 at 11:53 PM | Entropic man

Have you ever considered there may be a problem with Mann's Hockey Stick maths? Just because Climate Scientists have a 97% Consensus that they are right, doesn't convince Planet Earth.

Nov 17, 2017 at 11:53 PM | Entropic man

http://joannenova.com.au/2017/11/unknown-miocene-mystery-where-co2-didnt-fit-models-solved/

"Who knew there were large discrepancies and carbon dioxide did not fit the temperature theory for a million years or so? Not the public.

Where were the press releases telling us there was a mystery to solve?

Research Shows A High Temperature World Had Nothing To Do With CO2
Study shows temperatures fell dramatically, CO2 stayed the same
Study shows models have no freaking clue what controls the climate"

Golf Charlie

You check the validity of a paper's conclusions by replicating it.

There have been more than 70 replications using a variety of proxies from around the world. They all see a hockey stick.

Mann's maths may have been imperfect, but the climate pattern he described has been seen over and over again by other scientists.

The world cooled by about 0.4C from 5000BC to 1000AD.

It cooled by another 0.4C between 1000AD and 1850.

It has risen by 1C since 1850..

Rather than nitpicking a 20 year old paper, you might use your time better by finding a convincing explaination for this pattern which fits your beliefs.

Nov 17, 2017 at 11:53 PM | Entropic man

https://wattsupwiththat.com/2017/11/17/quote-of-the-week-effects-of-the-science-police/

"Mass, like the climatologists at Real Climate, has made a hobby out of fact-checking the media. But whereas Real Climate has periodically trained its eye on science distortions occurring in the partisan political and media realm, Mass has focused on mainstream media hyperbole. This has not won him any popularity contests."

EM returns, having forgotten acknowledging the MWP and LIA a few pages back.

EM, why was it necessary to keep trying to replicate Mann's Hockey Stick, if the science is settled?

What did Gergis 2016 actually achieve, apart from proving that Climate Science can't/won't correct/retract its own mistakes?

Isn't it time that Climate Science abandoned the Hockey Stick, as attempts to prove it, seem to be distorting all attempts at genuine research, and wasting money?

Nov 18, 2017 at 8:38 AM | rhoda

The history of the Climate, and Climate Science, is subject to variations and adjustments, even after it is settled.