DO NOT WASTE YOUR TIME reading this unless you want to see someone else's notes about possible posts in progress. If this information doesn't make sense to you please ignore this posting.
I offer this in part as a service to other writers -- It's often helpful and interesting when some else has tracked down various sources and URLs and made notes on the interesting bits.
A glimpse inside my investigation ... my comments in brackets [ ]
Explaining Extreme Events -Abstract wrote:
This sixth edition of explaining extreme events of the previous year (2016) from a climate perspective is the first of these reports to find that some extreme events were not possible in a preindustrial climate. The events were the 2016 record global heat, the heat across Asia, as well as a marine heat wave off the coast of Alaska.
-- https://www.ametsoc.org/ams/index.cfm/p ... /abstract/
THe "3 TENORS"
1. INTRODUCTION TO EXPLAINING EXTREME EVENTS OF 2016 FROM A CLIMATE PERSPECTIVE wrote:
• In a paper analyzing the 2016 global heat record by NOAA scientist Tom Knutson et al., the authors concluded that record global warmth “was only possible due to substantial centennialscale human-caused warming.”
• Similarly, a study of the record heat over Asia led by Yukiko Imada of the Japanese Meteorological Agency found that the extreme warmth across Asia in 2016 “would not have been possible without climate change.”
[The 1 paper I looked at, I picked the Pavaratti by chance? -- claims are more appropriate qualified, no mission impossible here.]
• In addition to these two papers looking at atmospheric temperatures, a team led by John Walsh of the University of Alaska determined that a large, persistent area of anomalously warm ocean water off the coast of Alaska (often referenced as “the Blob”) found “no instances of 2016-like anomalies in the preindustrial climate [simulation]” for sea surface temperatures in the Bering Sea.
-- http://www.ametsoc.net/eee/2016/2016_ba ... ow_res.pdf
3. CMIP5 MODEL-BASED ASSESSMENT OF ANTHROPOGENIC INFLUENCE ON RECORD GLOBAL WARMTH DURING 2016
Thomas R. Knutson, Jonghun Kam, FanRong Zeng, and andRew T. wiTTenbeRg
Knutson, header wrote:According to CMIP5 simulations[that we ran], the 2016 record global warmth was only possible due to substantial centennial-scale anthropogenic warming.
Ah! The difference a peer reviewed quality paper makes. I admit to feeling somewhat relieved, the radicals haven't completely taken over the editorial offices.
And some people like to beat you up for correctly labeling model results as "simulations"!
The inconsistency of observed long-term global warming with simulated natural variability (detection), and its consistency with simulations incorporating anthropogenic forcing (attribution), are in agreement with previous studies and assessments [that we considered]
Detect /attribution 101 - Important concepts. thank you
However, events as warm as 2016 are clearly possible in at least some of the All-Forcing experiments with anthropogenic forcing (Fig. 3.1a).
We therefore estimated ensemble and individual model p1’s, for the seven models having more than one All-Forcing/RCP8.5
Experiment = changing settings on simulation software -- this is one of the less potentially misleading uses (experienced readers aren't mislead ... once they learn the odd climate science usage of "experiment".)
Am I out of touch? Is there some field(s) that talk of models runs as experiments in published research?
RCP8.5 = high end of climate sensitivity
We conclude that for the seven individual CMIP5 models having adequate numbers of ensemble members
and having All-Forcing runs that are consistent with recent observations, the risk of exceeding the 2015
(2016) threshold is entirely attributable to anthropogenic forcing (FAR = 1).
Our analysis has important caveats. The internal variability of the climate system and the response to historical forcings have been estimated here using a combination of observations and models following Knutson et al. (2013, 2016). Uncertainties also remain in historical climate forcings by various agents, including anthropogenic aerosols. However, simulated internal variability would need to be more than twice as large as the most extreme case found in the CMIP5 models, for even the most extreme simulated natural warming event to match the 2016 observed record.
Summary.According to the CMIP5 simulations, 2016’s record global January–December warmth would not have been possible under climate conditions of the early 1900s—anthropogenic forcing was a necessary condition (Hannart et al. 2016) for the event.
OK as long as a FAR is presented as a estimate based in part on simulated/forecasts of climates.
the CMIP5 simulations = simulates run on estimates from " a combination of observations and models following Knutson et al.[/b] (2013, 2016)." CMIP5 simulations using my inputs.
Kinda puts a different light and context on: "events were not possible in a preindustrial climate."
Explaining Extreme Events -Abstract wrote:This sixth edition of explaining extreme events of the previous year (2016) from a climate perspective is the first of these reports to find that some extreme events were not possible in a preindustrial climate. The events were the 2016 record global heat, the heat across Asia, as well as a marine heat wave off the coast of Alaska.
I wonder what the AMS membership reaction is going to be? Fireworks soon?
It is striking how quickly we are now starting to see such results, though their dependence on model-based estimates of natural variability in the absence of human-induced change will require ongoing validation of the time-of-emergence for extreme event magnitudes at local scales.
Why "striking"? Really am curious what they were thinking. Noam Chomsky style I think of the often sited rhetorical pattern/trope: admit how far away we were up to now only once you think we've arrived.
Meaning: when phenomena first occurred? - circular
first occurred in models/virtual worlds? -- modeler shorthand?
It is helpful to consider the methodology used in these studies to understand the conclusions. Each
used the commonly accepted event attribution technique of calculating the fraction of attributable risk
(FAR) for the event, a statistical approach borrowed from epidemiology and public health, establishing [[calculating]] the probability of the event happening with greenhouse gas emissions at current levels due to human activity.
statistical calculations of probability should warn of probability and uncertainty!
not possible in the “control” planet
1. INTRODUCTION TO EXPLAINING EXTREME EVENTS OF 2016 FROM A CLIMATE PERSPECTIVE wrote:All three papers concluded that the FAR was 1, meaning that the event was not possible in the “control” planet, and only possible in a world with human-emitted greenhouse gases.
It should also be recognized that although FAR = 1 in relation to a human-induced impact in these cases, other climate drivers! that also affect the probability of such extremes may have been major additional contributors to the likelihood! of the event occurring.
Each of these papers applied large model ensembles (CMIP5 for both the global heat and Alaska marine heat wave analyses and the atmospheric general circulation model MIROC5 for the Asia heat study) to determine the FAR for these events.
-- good, honest phrase
and complete the thought guys --> and only possible in a [virtual] world/planet with human-emitted greenhouse gases.
That mod puts you on a intellectually honest 'planet' we can live on.
WE would CAUTION
... and ... the caution wrote:As is always the case, we would caution that the results of any single study should not be interpreted as the final word on the matter for that event, nor be generalized to a broader class of extremes.
For example, authors of these papers selected specific modeling approaches and made other choices about factors that are important in how the models replicate extreme events, such as terrestrial heat or sea surface temperatures. If other study designs were applied to these events, it is possible a different result would be reached.
The importance of the methodological approach in attribution research is further discussed in the summary of this report (Stott et al.).
This is the language the public needs to see.
Also: As is always the case, we would caution that the results of any attribution study should not be interpreted as the final word on the matter or confused with objective events. If other study designs were applied to these events, it is possible a different result would be reached.
On principle It is virtually certain (apodictic?) that some study designs (better, more complete theory; different climate sensitivity) would reach contradictory results. -- that is the tradition of normal science and scholarship.
While several of the studied events were found not to be possible without climate change, natural variability still laid the foundation for the events to occur, and the authors acknowledge this in their papers. Extreme events are always the result of a cumulative set of factors. The building blocks that form the foundation of any event continue to include natural variability, with factors such as El Niño potentially adding to the strength of the event.
SEEN to PALE in Comparison
These temperature-related extremes would likely still have been warm events [but not past extreme warm thresholds] even without human-caused climate change,
but according to these analyses, the [models simulated] events could not have surpassed the extreme warm thresholds that they did without climate change.
This was especially the case for the record-setting globally averaged temperature. At the global scale, the natural variations of Earth’s temperature are increasingly seen to pale in comparison to the growing intensity of human-induced warming. Overall, human-caused climate change allowed them to pass a threshold that they could not otherwise have exceeded.
increasingly seen to pale in comparison -- increasingly in whose eyes? Hansen didn't suspect in the 1980s?
a social construct, how long can this increasing go on before we burst in flames or something
I'm sorry I failed to appreciate just how right I was all along ... laughing at self
the natural variations - that is the crux of the issue % attribution, climate sensitivity
You got us at the serious possibility ---- stop gilding the lily; downplaying the uncertainty
Are you being served episode =3rd floor ... cosmetics, PR, "compelling narratives", Trump tweets
These papers also emphasize why clearer understanding of how human-caused climate change impacts extreme events is an important area of research. Retrospective analysis of previous extreme events may yield new insights into the history of human-caused climate change impacts, and we can expect to see insights into the extent and timing of the changes in the future
Granted ... but so is understanding of natural variation - how bout throwing a few more bucks just so we can pretend this is climate research
and the other shoe never drops --Retrospective analysis of alternative explanations used to be called doing science.
Explaination of The 2015 Report in the series
https://www.climate.gov/news-features/u ... blame-game
What is extreme event attribution?
Attribution is the process of giving credit for something, like crediting all the people who were involved in making a movie. Like a movie, any extreme event has lots of contributors; extreme event attribution is the science of deciding whether manmade global warming was one of them. Extreme event attribution tells us how much of the credit or risk for an event (or type of events) should go to global warming and how much should go to natural weather patterns or random climate variability.
Why do extreme event attribution studies?
Knowing whether global warming influenced the probability or intensity of an extreme weather event can help people in affected communities develop recovery and resilience plans that match their future risk. Research has already connected global warming to changes in the frequency of certain extreme events, including heat waves and extremely heavy rain, on a global scale. The goal of extreme event attribution is to provide a local-scale perspective that people, communities, and businesses can use to better anticipate future changes in extremes at their specific location.
- Important terms: Detection and Attribution.
- Detection is when research into weather records of actual measurements of past weather detects changes in the frequency of certain extreme events, including heat waves and extremely heavy rain, on a global scale.
- As with the IPCC AR5 SPM, just those two extreme weather events are named but not others. That is intentional.