Reply #45: The paper refutes the assertion that there is significant overestimation (on 20 y/o data).

[joshcryer]

I provided further details in a post below. 1990 IPCC was not even prepared to say CO2 caused global warming, that global warming was even happening, it merely made projections that may be possible from known physics. The final numbers were, in fact, within the margin of error. This is amazing given that they were based on very little empirical evidence at the time! (Just basic physical equations Hansen et al came up with in 1981, 1988.) Remember, global temperature rise was not discernible from background noise until the mid to late 90s at best. This is one reason why, if you ever noticed, denialists stop their graphs at the 90s.

Note that Nederland exposes his obvious bias when he discusses sea level rise in AR4, unwittingly failing to recognize that AR4 doesn't even consider this kind of arctic meltoff. He's obviously been reading too many skeptic websites, and it has clouded his understanding of the issue, and presumably, your own.

Rather than discussing the basic points we then get into these tangential discussions about scientists and blogs, and whether or not a 15 year old chemistry student is brilliant or not.

Facts. Has IPCC been accurately estimating the warming trend for at least 7-8 years? Yes. Did the 1990 report even claim to know that global warming was happening or being caused by CO2 emissions? No. Therefore they are simply not comparable.

The whole argument falls apart when you see where Neaderlands bias lies:

Except of course, when they overestimate things...

In the 1990 IPCC report, temperature rises where estimated to be at the 2.5 degrees per century <...> that estimate proved to be slightly higher than what actually happened in the 18 years that followed.

It was within the margin of error, in a report that could not claim to know that global warming was happening due to CO2 emissions, based on little empirical evidence. Overestimate? Holy shit, they were almost right on target. Off by freaking .5C? Seriously? Oh wow.

As far as sea level rises go, I'd be curious to see why the author of this study believes the IPCC ar4 estimate of 19-58 inches of rise is inaccurate.

Bias exhibited. If IPCC could "overestimate" on the warming features (again, with very little data, and almost guessing based on some guys equations), then clearly these guys could be having the same problem.

Of course, he didn't realize AR4 did not include arctic sea level rise in their equations. Thus invalidating his "concerns" from the onset. The whole fucking discussion is pointless and no one here will learn shit about the scientific process.