Sentences with phrase «ipcc attribution»

I continue to think that your focus on the IPCC attribution statement is a losing proposition, but having made that point several times already, I can't add further to it.

Since there doesn't seem to be a way to directly incorporate accurate feedback effects into the IPCC models, how does feedback fit in the IPCC attribution argument?

In the context of the IPCC attribution statement, as a lay person, I would take it to mean something much greater than 50 %, e.g., 80 - 90 %, upon first reading.

Even before seeing Gabi Hegerl's comment, I had come to a somewhat similar conclusion — that your draft gave the impression that IPCC attribution of most warming since about 1950 to anthropogenic greenhouse gases was based exclusively on the difference between model runs with and without anthropogenic influences.

And doing this has led Skaggs to the main flaw in the IPCC attribution case:

Have we seen statements from Drs Schmidt and Romn that the IPCC attribution statement is not settled?

Even Judith has continued attacking the IPCC attribution statement even though it's supported by the TCS figures she posted on the last thread!

His referenced post on the IPCC attribution chart indicates the IPCC considers the net natural influence on the period as 0.00 °C.

Gavin's response IPCC attribution statements redux: A response to Judith Curry http://www.realclimate.org/index.php/archives/2014/08/ipcc-attribution-statements-redux-a-response-to-judith-curry/

Per Mosher basically Judith is accepting the IPCC attribution as fact and merely calculating a sensitivity GIVEN that.

if you plug in the numbers from your paper with Nic Lewis into the change in GHGs over the period covered by the IPCC attribution statement, what proportion of temperature change is attributed to anthropogenic and what to natural?

The IPCC attribution arguments (as opposed a rigorous scientific treatment of the question) operate under several constraints: the need to fit concerns for positive feedbacks, the need to not accidentally produce a very low value for sensitivity, the obligation to accommodate, and at times, exploit such unknowns as aerosols (very useful but also a pain), and so forth.

The timescales (25 years) relevant to the argument made in the first paragraph are not relevant to the IPCC attribution statement (60 years).

It is very consistent with the IPCC attribution since 1950.

geez sunshine you do nt seem to realize that reducing the warming since 1945 actually reinforces the IPCC attribution statement... if there's less warming then CO2 caused a higher % of it.

Note that lowering the temperature rise since 1951 would strengthen the IPCC attribution statement.

I.e. lots of scientists highly confident in IPCC attribution without publishing in this area or even reading the primary literature.

That the TCR is consistent with the IPCC attribution is a bonus for those interested in the scientific backup.

Whether the IPCC attribution is accurate or not, the more central point is that one can't merely compete anthropogenic and non-anthropogenic influences purely as a function of time.

The phrasing of the IPCC attribution statement in its fourth assessment report (AR4)-- providing a lower limit for the isolated GHG contribution — may have led to an underestimation of the GHG influence on recent warming.

«uncertainty» (in the IPCC attribution of natural versus human - induced climate changes, IPCC's model - based climate sensitivity estimates and the resulting IPCC projections of future climate) is arguably the defining issue in climate science today.

JTFs: The IPCC attribution statement is limited to the period since 1950 precisely because studies fail to attribute a significant amount of warming before then to anthropogenic forcing.

Again IPCC attribution statement: «It is extremely likely [95 percent confidence] more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.»

They are quite obviously and deliberately avoiding the fact that * their own figure * backs the IPCC attribution statement.

Mirroring the IPCC attribution statement.

Yes, the «skeptics» who deny the IPCC «most» attribution are being pushed further into greenhouse dragonslayer territory by these facts on the ground, but they need to run the numbers for themselves, and check what they are saying before reflexively denying the next IPCC attribution statement.

Puzzling isn't it how skeptics, including Dr Curry, claim to have a problem with the IPCC attribution statement but promote Nic Lewis's TCR figures at the same time!

This backs up the IPCC attribution statement «It is extremely likely [95 percent confidence] more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.»

Perhaps you could be the person who can take me out of my misery and explain how the 2 aerosol paradoxes that I mentioned below can be reconciled with the IPCC attribution position.

This is probably why the IPCC attribution since 1950 has become even more confident in AR5.

I believe her emphasis on uncertainty has made a valuable contribution to the climate science dialog, even though, as she knows, I disagree with her about the merit (as I see it) of the IPCC attribution of most post-1950 warming to anthropogenic GHGs.

I refer to this generally in my draft «uncertainty monster» paper (will resume working on the revisions to that paper once my proposal is submitted) as a significant reason in support of my thesis that the «very likely» statement in the IPCC attribution statement is over confident

It should be noted, of course, that the IPCC attribution statement only covers the period 1951 - 2010.

There is a new post at RealClimate IPCC attribution statements redux: A response to Judith Curry, which responds to my post The 50 - 50 attribution argument.

Not exact matches

Two important advances since the last IPCC assessment have increased confidence in the use of models for both attribution and projection of climate changes.

The International Detection and Attribution Group (IDAG) is a group of specialists on climate change detection and attribution, who have been collaborating since 1995 on assessing and reducing uncertainties in the estimates of climate change, and who have made substantial contributions to the IPCC process and the US CCSP Attribution Group (IDAG) is a group of specialists on climate change detection and attribution, who have been collaborating since 1995 on assessing and reducing uncertainties in the estimates of climate change, and who have made substantial contributions to the IPCC process and the US CCSP attribution, who have been collaborating since 1995 on assessing and reducing uncertainties in the estimates of climate change, and who have made substantial contributions to the IPCC process and the US CCSP activities.

I have no desire to have a «blog debate» but rather I am making the point that hurried «interpretations» of results aren't generally very accurate and that people can be in too much of a hurry to jump to conclusions about the IPCC, attribution, impacts on policy etc..

Apart from the undefined meaning of «most» in AR4 (which was subsequently clarified by the IPCC), the range 50.1 - 95 % is rather imprecise in the context of attribution.

If so, this has little or no relevance to the detection or attribution of climate change and thus no importance to the main IPCC conclusions.

Before getting into my 50 - 50 argument, a brief review of the IPCC perspective on detection and attribution.

The idea that a blog post on WUWT that doesn't even deal with attribution overturns all the work on detection and attribution in the IPCC reports is laughable.

Back in 2008, a cottage industry sprang up to assess what impact the Thompson et al related changes would make on the surface air temperature anomalies and trends — with estimates ranging from complete abandonment of the main IPCC finding on attribution to, well, not very much.

Let me clarify the distinction between detection and attribution, as used by the IPCC.

I'd add the more recent US National Climate Assessment attribution statement to # 8, as its a bit more specific than the one in the IPCC.

The two IPCC statements discussed attribution to greenhouse gases (in AR4) and to all anthropogenic forcings (in AR5)(the subtleties involved there are discussed in the 2013 post).

The IPCC then regards the divergence between unforced and anthropogenically forced simulations after ~ 1980 as the heart of the their detection and attribution argument.

This is a result that has been suggested before (i.e. in the IPCC report (Groisman et al, 2005), but this was the first proper attribution study (as far as I know).

I must say, having read this post and all the ones linked to it including the IPCC chapters, that I do not recognize some of the claims as being part of attribution as applied by practitioners.

I've just reread Overconfidence in IPCC's detection and attribution.

The IPCC's attribution statement does not seem logically consistent with the uncertainty in climate sensitivity.