The earliest ice outs, and thus the warmest years, were in the 1950s. The warming from 1975 to 1998 is real, but not very large – just a blip in the overall cooling trend from 1950.
During the 1950s, Winnipesaukee ice outs were generally around Julian day 100, which is usually April 10. These days, it is around Julian day 107, which is usually April 17 – the ice is taking longer to melt, therefore, these days the weather is cooler than it was in the 1950s.
Data and calculations here – you will not find that replicability if you look at “peer reviewed” research.
If one selects the lakes with the best data, no sign of twentieth century warming.
Similarly for the weather station record. which indicates no twentieth century warming
The vertical axis is the Julian day number of the ice outs. The little green dots are the julian numbers of ice out days for particular years, the graph is the seven year rolling average of the ice out day. Smaller numbers, representing warmer years, are at the top of the graph, larger numbers, representing cooler years, are at the bottom. Lake Winnipesaukee was selected because lots of people who have no interest in global warming have an interest in this ice out day and report it, because it enables them to do business and get to their properties, hence the ice out day is a valid number. It is the top hit in google for ice outs, excluding global warming related hits.
Lakes whose ice out day is subject to less interest are likely to have the same reliability problems as the instrumental temperature record. If one has to look hard for historical data, that data is unlikely to be accurate because few people were monitoring it. Since the data is likely to be inaccurate, one can always cherry pick data that proves anything one wants to prove, which cherry picking is apt to slowly become making up data outright – since one already supposedly knows what the data should show, searching overly hard for data that one knows must be true is apt to become outright forgery, as the Climategate documents directory shows happened with the instrumental temperature record.
If there are gaps in the data, as there generally is with the instrumental record and with many lake iceouts, that means few people are monitoring it. If few, then perhaps none, perhaps the data is consciously or unconsciously fraudulent, and whether legitimate or not, no way to prove it legitimate. Incompleteness is a symptom of other problems. If a lake is so obscure that one cannot find a lake ice out for this year on the internet from boating enthusiasts, did anyone really find the lake ice out for 1950, or did they just make it up?
It is hard to estimate global climate from the instrumental record, but the most plausible evidence, if we exclude cities for the urban hot spot effect, and use only climate stations with good stability, refraining from efforts to patch together lots of fragmentary climate station records of unclear provenance, is that the 1950s were the warmest period in the twentieth century, and that the warming from 1975 to 1998 was just a small fluctuation in the long term cooling trend since 1950
The documents directory of the climategate files reveals that Harry could not derive global temperatures from the instrumental data, that the hadcrut global temperatures, the supposed instrumental record, had come right out of Tim’s ass.
Various people have attempted to reconstruct the global temperature record from the instrumental record but the data are not of quality that would enable this to be done. The jumps resulting from moves of weather stations and suchlike are much larger than the climate changes one is trying to detect. You cannot get a silk purse out of a sow’s ear. Weather stations keep moving their thermometers, changing the way they record data, and so on and so forth. Until 2004 no one was trying to do measurements that would be suitable for evaluating climate change – some would say they were trying from 1998, but they surely were not succeeding until 2004.
The only instrumental global temperature records are, like the climategate instrumental record, the result of someone’s secret sauce which they will not reveal, for no one who will reveal his method of calculation can produce anything from weather station data that they will claim to be plausible or credible. Lots of people have tried.
For some examples of the difficulties encountered, see Watts up with that, xx, xx. The GHCN adjustments were obviously fraudulent and intended to create fake global warming in the instrumental record, but it is impossible to say what adjustment would be reasonable and uncontroversial. There is room enough in the gaps between one weather station and the next to manufacture global warming, global cooling, or have temperatures dance the watutsi. Obvious the CRU was wrong to exclude those weather stations that showed world temperatures falling – but if the world climate trend depends on what stations you exclude and what you include, one can have little confidence in the trend derived from any particular set of weather stations.
Science is replication, not peer review.
What happens behind the scenes in peer review was revealed in the climategate emails
Peer review, as revealed in the climategate emails, is in practice theological review. If it is peer reviewed, it is a lie. If it appears in “Nature” or “Science” it is a lie. The truth is not allowed.
Which fact is obvious from the fact that non peer reviewed reports show their data and method of calculation, and peer reviewed reports on political topics do not. If it is peer reviewed, it cannot be replicated. If it cannot be replicated, is not science.
Working through these non peer reviewed reports, replicating them, one can prove that various peer reviewed reports are criminal frauds. When we got the inside info, when the climategate files came out, we found in the documents directory the programs that did what we had already proven had been done. Climategate confirmed what replicated research had already proven. Replicated is the gold standard. Peer reviewed is not.
We had already proven that global warming was criminal fraud. Then we got confirmation from inside in the Climategate files, proving that our account of how global warming was cooked up was indeed how it was cooked up.