Judith Curry: Attribution der modernen Erwärmung muss auf den Prüfstand

Marijn Poels im Gesräch mit Judith Curry:


Lesenswerte Analyse von Judith Curry aus dem Januar 2019:

A careful look at the early 20th century global warming, which is almost as large as the warming since 1950.  Until we can explain the early 20th century warming, I have little confidence IPCC and NCA4 attribution statements regarding the cause of the recent warming. [...] 

In order to have any confidence in the IPCC and NCA attribution statements, much greater effort is needed to understand the role multi-decadal to millennial scales of internal climate variability. Much more effort is needed to understand not only the early 20th century warming, but also the ‘grand hiatus’ from 1945-1975.  Attempting to attribute these features to aerosol (stratospheric or pollution) forcing haven’t gotten us  very far.  The approach taken by Xie’s group is providing important insights.

Once we do satisfactorily explain these 20th century features, then we need to tackle the 19th century — overall warming, with global sea level rise initiating ~1860, and NH glacier melt initiating ~1850.   And then we need to tackle the last 800 years – the Little Ice Age and the ‘recovery’. (See my previous post 400 years(?) of global warming).  The mainstream attribution folk are finally waking up to the importance of multidecadal ocean oscillations — we have barely scratched  the surface re understanding century to millennial scale oscillations, as highlighted in the recent Gebbie and Huybers paper discussed on Ocean Heat Content Surprises.

There are too many climate scientists that expect global surface temperature, sea ice, glacier mass loss and sea level  to follow the ‘forcing’ on fairly short time scales.  This is not how the climate system works, as was eloquently shown by Gebbie and Huybers.  The Arctic in particular responds very strongly to multidecadal and longer internal variability, and also to solar forcing. Until all this is sorted out, we do not have a strong basis for attributing anything close to  ~100% of the warming since 1950 to humans, or for making credible projections of 21st century climate change.

Ganzen Beitrag bei Judith Curry lesen.


Terry Etam am 22. Mai 2019 in boereport.com:

When serious climate-change news is funnier than satire, is it the end of the world or the rebirth of common sense?

[...] So, what happened was that I noticed a tweet in the endless stream from one of the sharpest minds I’ve encountered on the web, a fearless jouster known as DawnTJ90. She (I assume, who knows) posted a link to a story about how climate change is making sharks right handed. I marvelled in a quick comment that these parody sites are getting very creative and funny. Then I followed the link, read the story, and realized that it was serious – yet another group of grant-harvesters was “studying” this climate-change consequence and had actually published research on it, with a straight face. [..] This mass hysteria isn’t unprecedented; in fact, mob rule is a common human habit that has popped up through the ages. We are steps away from another mob takeover, a potentially massive one; we have loons gluing themselves to roadways in Europe to protest something or other (despite the sounds coming out of their mouths, they aren’t protesting for what they say they are, or they would never fly or use fossil fuels again). Other vacuous climate-saving tacticians climb over pipeline-facility fences to mindlessly start turning valves, which they apparently believe to be some sort of earth thermostat. [...] While that is going on, the public will reach the crossover point, just as I did, where it can no longer tell the difference between parody and the news. We are very close. At that point, the world will smell a rat with respect to all the climate doom predictions, once people realize that they aren’t dying as quickly as they are supposed to be, that their world has not been turned into a desert or been submerged, and that shark bites feel exactly the same whether the beast throws with its right fin or left. [...]

Ganzen Beitrag hier lesen.


Yale-ProfessorJustin Farrell gibt in einer Pressemitteilung Tips, wie man Kritik am Klimaalarm verhindert. Er empfiehlt, gegen die Person anzugehen, anstatt sich nur auf die Argumente zu konzentrieren. Desweiteren schlägt er Gerichtsverfahren vor und Attacken gegen die Finanzierung von kritischer Forschung. Unglaublich, dass ein solcher Mann so offensichtlich gegen die freie Wissenschaft argumentieren kann, ohne dass seine Universität ihn zurückpfeift. Ein weiterer Schritt hin zur Gleichschaltung der Kimawissenschaften. Farrell hatte bereits früher Untersuchungen durchgeführt, die von Greenpeace mit Kusshand verwendet wurden. Über die mächtige IPCC-nahe Durchreichestiftung “European Climate Foundation” sagt die Pressemitteilung übrigens nichts.


Pressemitteilung der Oregon State University aus dem Januar 2019:

Trout, salamander populations able to quickly bounce back from severe drought conditions

Populations of coastal cutthroat trout and coastal giant salamanders in the Pacific Northwest show the ability to rebound quickly from drought conditions, new research by Oregon State University suggests.

The findings, published in the journal Hydrobiologia, indicate that the fish and salamander populations can get back to predrought form within just a few years. That’s important because climate change is anticipated to make drought years such as the one in this study – 2015 – occur more frequently, and the resilience of these dominant stream predators suggests they will be able to persist as long as the droughts do not occur many years in a row. “What we found buys us time to try to fix climate change as best we can or at least keep it where it is right now,” said study co-author Dana Warren, an OSU faculty member in the College of Agricultural Sciences and the College of Forestry. “If we can do that, the populations in these headwater streams will be fairly resilient, but if not, they’ll clearly be more threatened.”

The drought conditions of 2015 occurred in the study streams because there was limited snowpack in the winter and spring that resulted in low stream flows that started a lot earlier than usual, said corresponding author Matthew Kaylor, a graduate fellow in fisheries and wildlife in the College of Agricultural Sciences. “That led to much lower flows throughout the summer,” Kaylor said. “Assessing impacts to the drought provided an insight into how these populations may react to changing conditions in the future since climate models suggest lower snowpack and lower summer stream flow.”

Trout and salamanders in the nine Cascade Mountain headwater streams from this research – part of a long-term study site – were both negatively affected by the hot, dry summer of 2015, though they responded differently. Adult trout numbers were down in 2015 compared to 2014, which had conditions closer to historic norms. “Stream conditions would suggest that increased mortality was the likely factor leading to lower numbers of fish during the drought,” Kaylor said. “However, we can’t actually say for sure with our data. Disentangling mortality versus movement to other habitats during droughts is a question we would like to tackle in the future.” Salamanders did not show any consistent changes in abundance across the nine sites in 2015, but their body condition declined in all study streams. As with trout abundances, the salamander populations were all back in predrought shape within a year or two.

“The trout and salamanders recovered quickly, which is important as we look into the future,” Kaylor said. “In these cool streams, if drought conditions persist over multiple years, that’s probably bad news for the trout and salamanders, but if they’re more sporadic, then those populations may be resilient.” Interestingly, juvenile trout didn’t appear to be negatively affected by the 2015 drought – they were in fact bigger in all streams during the drought year. “Young fish responded differently than adults, possibly because temperatures were warmer, which led to earlier hatching and faster growth, ” Warren said. “But it also could be because there were fewer adult trout to compete with. Either way, the response of the young fish was likely critical in promoting abundance recovery the following years for most sites.”

Also of note: Contrary to what the researchers had expected, stream temperature was not strongly associated with how trout and salamanders responded to the drought. “All of the streams we sampled were relatively cool and generally remained below the temperatures that would cause stress,” Kaylor said. “Stream pool habitat was important for trout, though. Stream sections with more deep pools showed smaller reductions in trout abundance and biomass.” Added Warren: “We know that habitat features like pools are important when they’re creating areas of flow refuge and areas of terrestrial predator refuge. Those same pools appear to be important in insulating a system against drought as well.”

The one stream where the fish population didn’t return to its predrought status was “an isolated stream near the edge of fish distribution,” he said. “That site is illustrative of the type of system that’s most vulnerable,” Warren said. “At that site salamanders have done well, but the trout haven’t come back, and that gives a hint about the kinds of streams we really do need to be concerned about versus the ones that may be more resilient. Location is important, not just stream size or habitat.” For the next few decades, Warren points out, droughts like 2015’s won’t happen all the time. “We’ll get them periodically, and that periodicity is likely to increase, but it’s not like a switch will flip to a new normal,” he said. “We will get to that new normal, though, if nothing changes.”

The National Science Foundation, the U.S. Department of Agriculture, the U.S. Forest Service, the HJ Andrews Experimental Forest, and Oregon State University supported this research.