"This reply is essentially a restatement of the same argument you've made before: that proxy limits imply rates are unknowable and modern change may therefore be unremarkable."

Yes. And I'll keep making the point in the faint, but disappearing, hope that the penny will drop.

Marcott showed two valuable things....1/ current temperatures are unremarkable in regards to the past 12000 years; and 2/ the claims that temperatures are rising faster than in the past is based on assertion rather than data.

Answering the question "Is the rate of global temperature rise over the last 100 years faster than at any time during the past 11,300 years?" Marcott said..."the paleotemperature records used in our study have a temporal resolution of ~120 years on average, which precludes us from examining variations in rates of change occurring within a century. Other factors also contribute to smoothing the proxy temperature signals...such as organisms burrowing through deep-sea mud, and chronological uncertainties in the proxy records.... We showed that no temperature variability is preserved in our reconstruction at cycles shorter than 300 years, 50% is preserved at 1000-year time scales, and nearly all is preserved at 2000-year periods and longer... Any small “upticks” or “downticks” in temperature that last less than several hundred years in our compilation of paleoclimate data are probably not robust, as stated in the paper."

JD doesn't want that to be true, and in his world that the same thing as it not being true.

Neukom et al., 2019 has been comprehensively debunked for all sorts of reasons...1/ it has a paucity of southern Hemisphere data; 2/ it's Northern Hemisphere data is highly selective; 3/ it ignored the well established seasonality in proxy data.

Basically the alarmists work on the basis that any area where the data is vague or uncertain should be interpreted in favour of the great scare. ie the data can't show whether or not temperatures are rising faster than in the past, therefore we'll assert they are. Its the opposite of science.

So here's where we end up. We have a data that shows "Mean ocean temperature change over the past 4.5 million years" have been steadily declining for thousands of millennia and are close to the lowest they've been over that period. Yet JD doesn't want that to be true and in his world that's the same as it not being true.

And we have data that shows that current temperatures are completely unremarkable in terms of the entire Holocene. But JD doesn't want that to be true and in his world that's the same as it not being true.

But in the same breathe he'll claim to be following the science!!

This line says exactly what I've been pointing out, mhaze.

//Marcott said..."the paleotemperature records used in our study have a temporal resolution of ~120 years on average, which precludes us from examining variations in rates of change occurring within a century.//

Marcott cannot resolve centennial-scale rates. It does not show that modern rates are normal - it shows that Marcott is not the dataset for assessing them. Turning "cannot resolve" into "must be unremarkable" is a category error.

//"no temperature variability is preserved… at cycles shorter than 300 years." – Marcott//

That means short bursts of rapid change in the past would be smoothed out, not preserved. It cannot be used to argue that past rates matched modern ones, only that Marcott cannot tell you either way.

//current temperatures are unremarkable…//

Marcott never said that. In fact, he avoids drawing that conclusion because of the very limitations you quoted. That leap is yours, not his.

//Neukom et al., 2019 has been comprehensively debunked…"//

Sources?

You've repeated this claim several times without citing a single peer-reviewed rebuttal. Meanwhile, Neukom exists precisely because Marcott cannot resolve centennial-scale rates. Ignoring the higher-resolution work and leaning entirely on the lowest-resolution dataset is exactly the pattern I pointed to.

//Mean ocean temperature… lowest they've been…//

Clark et al. reconstruct multi-million-year equilibrium ocean temperatures. They do not claim modern oceans are "close to unprecedented lows", and they say nothing at all about modern transient warming. That interpretation again comes from you, not the authors.

We've been through this twice before:
low-resolution dataset -> therefore rates are unknowable -> therefore modern rates might be normal -> therefore concern is hysteria.
When higher-resolution work was brought in, it was dismissed in generalities rather than addressed.

If the claim is now that no proxy reconstruction can constrain past rates, then that needs to be argued consistently - including for the papers you're relying on. Otherwise, we're just looping the same argument under a new heading.

Try again.

I mentioned at the outset that a paper purporting to show massive costs of climate change had been withdrawn due to flawed data. That paper, released with the usual hoopla, was used as the basis of all sorts of policies by the World Bank, US Congressional Budget Office, the UK Office for Budget Responsibility and the OECD.

Now that the paper and its conclusions have been thoroughly debunked you'd expect that these organisations would revisit the policies and recommendations that they implemented based on flawed data. But you'd be wrong.

As with most things in so-called climate science, the outcome is the point, the data merely a means to an end. And if the data proves uncooperative, it can be ignored. (See above).

Given up on the data now, mhaze?

You're now talking about institutional behaviour and policy inertia, not the scientific questions we've been discussing.

A single withdrawn paper - however widely cited - does not invalidate an entire field, nor does it follow that major policy bodies based their assessments or recommendations on that paper alone. Those institutions draw on large, cumulative evidence bases, not one study.

Again, retractions are part of scientific self-correction. Treating them as evidence that "the outcome is the point" conflates how science works with how policy responds to uncertainty and risk.

More importantly, this doesn't address the issues we were actually debating: proxy resolution, rates of change, or the misuse of deep-time reconstructions to dismiss modern forcing.

If the discussion is now about distrust of institutions rather than the physical evidence itself, that's a different conversation entirely.

It's also hard to miss the fact that you treat papers decisive when they can be read against climate concern, but as institutionally compromised once their implications cut the other way.

I'm guessing Marcott is no longer reliable...

"You're now talking about institutional behaviour and policy inertia, not the scientific questions we've been discussing."

No I'm adding meat to the bone of what I mentioned in the very first post which you've tried so hard to ignore because its inconvenient.

"Marcott never said that."

The paper specifically says that current temperatures were exceeded 25% of the time during the Holocene ie, 3000 of the past 12000 years (approx) were hotter than now.

This is all very funny, and sad. Here were have two graphs based on real data which show, respectively, that current temperatures have often been exceeded in the past 12000 years, and that mean ocean temperatures have been declining for 4.5 million years; and in both cases JD refuses to see the data. And then tells us he's all about The Science