Wow.
Perhaps unsurprisingly given the exceptional (relative) warmth in Alaska last month and in February, the record for the Nenana Ice Classic was shattered this year.
The previous official record was associated with the exceptional conditions in El Niño-affected winter of 1939-1940, when the ice went out on April 20th 1940. Though since 1940 was a leap year, that was actually a little later (relative to the vernal equinox) than the ice out date in 1998 (which wasn’t a leap year).
Other records are also tumbling in the region, for instance the ice out data at Bethel, Alaska:
The Kuskokwim River at Bethel has gone out. This is, by far, the earliest breakup in the 90+ years of breakup data. This follows the warmest February and warmest March on record. @kuskoiceclassic @Climatologist49 @AlaskaWx pic.twitter.com/auEfe0YQ7J
— International Arctic Research Center (@IARC_Alaska) April 13, 2019
While the trend at Nenana since 1908 has been towards earlier ice-out dates (by about 7 days a century on average), the interannual variability is high. This is consistent with the winter warming in this region over that period of about 2.5ºC. Recent winters have got close (2012/14/15/16) (3 to 4 days past the record), but this year’s April 14th date is an impressive jump (and with no leap year to help calendrically).
As usual, I plot both the raw date data and the version adjusted to relative to the vernal equinox (the official time of breakup was ~12:21am).
[As usual, I predict that there will be no interest from the our favorite contrarians in this]
There’s also a record of the ice-out date on Lake Winnipesaukee in New Hampshire.
https://en.wikipedia.org/wiki/Lake_Winnipesaukee_Ice-Out
There the trend is -5.6 days/century since 1887, but the 30-year trend is -28 days/century.
Most impressive is Severnaya Zemlya in Russia, the last archipelago in the world to be mapped, under Stalin.
Stalin also seems to have borrowed Graf Zeppelin to fly over it for possible mapping..
But in quite recent years, it has been possible to sail all the way around both Severnaya Zemlya and Franz Josefs land during the season..
However, there seems to have come more frost again in the Northwestern passage, where a private katamaran with sails and outboard motor plus even a large passenger cruise ship with paying passengers passed through for the first time, some years ago.
According to sea ice maps, Roald Amundsen would not have come all the way to Gjøa Haven by the first season, in 2018. And he froze tight at Cape Chelyuskin With his new ship Maud in 1918. Where Nordenskjølds polar ship Vega and Fr.Nansens Fram had easily passed through in the season decades earlier.
When do we get to call it a downward hockeystick?
One lake in New Hampshire? Why not go to the Land of 10,000 Lakes and check out some real statistics
http://img706.imageshack.us/img706/9683/v4hb.jpg
What’s nice about tracking ice-out dates is that the data doesn’t suffer from UHI effects, instrument changes, calibration issues, etc. that will impact thermometer readings.
Catastrophic climate change is on its way.
Climate Change Emerges as Key Issue in Close Finland Election
This smashed the previous record earliest melt, which lasted for 79 years, by over 6 days!
Hey, dudes, it’s just one year of ice melt, don’t get all sky-rockety, but hang on to your hats!
I am hoping to hear Nigel put this in context for us all.
Cheers,
Mike
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@mike #8. It’s 90 years of ice-out data–not one. That is all.
The most reliable signal from rising trends in temperatures come from ground temperature profiles in permafrost boteholes. Since the permafrost (if continous) prohibits water circulation in the ground, there are no other influences on ground temperature than temperature at the ground surface. This of course can be changing because of other variables than the air temperature, mainly thickness and duration of snow cover, caracteristics of the vegetation and moisture content of the active layer (the uppermost part of the ground, which thaws every summer and is therefore not part of the permafrost – mainly ranging from av few decimeters in cold arctic regions up to several meters above “warm” alpine permafrost fx here in Southern Norway). Since the ground is a slow conductor of heat, the shape of the mean temperature curve down in the ground will give a very good indication of the trend in air temperatures at the location of the botehole bakcwards in time, provided there are no big changes in snow conditions. Fx in Svalbard a borehole at Janssonhaugen near Longyearbyen gives a very clear signal from the exceptionally fast rising air temperatures in Svalbard in the last several decades. Normally you would expect the depth of zero annual amplitude (zaa) to be around twenty meters, but now in the latest decades zaa is at around sixty meters depth. Almost exactly the same extreme warming trend is seen in akaskan boreholes and boreholes in the Alps, in scandinavian mountain regions etc.
Sorry for my writing errors: boreholes (not boteholes) and characteristics (not caracteristics).
For some data on ground temperatures in Svalbard compared to other arctic regions have a look at slides 6 and 7 here: https://www.slideshare.net/mobile/UniSvalbard/svalbard-seminar-series-2018-permafrost
to dan at 10: I have reconsidered. The ice-out stat for this year looks bad.
It could be an outlier, but I don’t think it is. The outlier argument is likely to be made by many about this year’s early ice out date. We haven’t hit Wadhams territory yet, but I honestly don’t think this ice out data point is an outlier.
The warming of the Arctic could turn out to be a big problem with numerous feedback consequences. I tire of typing in these concerns because I can be assured that numerous folks who post here regularly will try to act like the adults in the room and minimize the concerns.
It’s too bad that our species is not willing to do very much about the underlying problem of CO2 emissions and CO2 accumulation in atmosphere and oceans.
Per #9: I know the moderators have better things to do with their time, but I question the utility of slowing discussion by delay for moderation when a spam post about toothpaste etc. apparently passes muster and makes it through the moderation process.
But who, knows, maybe someone here was really scratching their head about toothpaste…
Cheers
Mike
You might find this interesting:
“Finally, as everyone knows, breakup has already occurred at Nenana and Bethel, and it was the earliest on record for both locations. This morning, however, the Kuskokwim at Bethel was glazed over again with a dusting of fresh snow; this seems like a pretty unusual event (freeze-over after spring breakup), but others might know if it’s been seen before.”
https://ak-wx.blogspot.com/2019/04/winter-lives.html
Here’s a thought regarding Arctic ice: Low extent in winter is like setting an open pot of water out under a cold, clear night. A ton of energy escapes to space, nothing is gained.
Different in summer, when an open pot lets the sun in, more than compensating for the extra loss.
****
So, low extent may reduce global OHC in Winter, even though it most certainly increases it in Summer. Global because the Arctic Ocean is not independent of the others.
#16, Snape–
Yes, open water in winter constitutes a recognized negative feedback mechanism on ice extent changes, I believe. It’s certainly been discussed at Neven’s Arctic Sea Ice blog:
https://neven1.typepad.com/
And not only open water, I believe: the drastic thinning of virtually the entire ice pack means increased heat flux during winter from the ocean to the atmosphere through the ice.
But how much of that energy ends up escaping to space and how fast, depends on atmospheric conditions, notably cloud structure and coverage. If you wanted the planet to warm as fast as possible, you’d be cheering for lots of winter cloud (especially at higher altitudes) but for sunny late summer skies, when the water can absorb all that sunshine.
Snape: So, low extent may reduce global OHC in Winter,
AB: That would be the case if H2O’s best and highest use for radiation management was its liquid form. But H2O affects radiation in its gaseous phase. Exposed water releases more water vapor into the atmosphere than exposed ice. Thus, when your sea ice melts the humidity generally goes up and as you know, H2O in vapor form is THE way to heat a planet the bestest. Plus, ice is perhaps four times better at conducting heat than liquid water (though it doesn’t do convection). Anyway, this subject came up a year or two ago (I believe Hank Roberts spotted the study). The effect is so strong that some scientists thought (don’t know current thoughts) that once we get to arctic-sea-ice-free summers we will pretty much instantly jump to nearly ice-free winters, too.
You all need to start appearing on the media and fighting back against the oil lobby. I’ve been following this on and off for the last 12-13 years but it’s not reaching the masses. Go post on fox news comments to fight against their misinformation you could destroy the people posting on there, go post on reddit, go do interviews in the media it’s time to get a little more aggressive, doesn’t feel like this is a war that is winning.
#16, 17, 18,
Snape: “{1}So, low extent may reduce global OHC in Winter, even though it most certainly increases it in Summer. {2}Global because the Arctic Ocean is not independent of the others.”
Here’s how someone with a science/quantitative background might say things:
1. Low extent in the Arctic increases radiation to space. But, that fact by itself tells us nothing about whether global OHC increases or decreases during that time period, because there is radiation and absorption going on everywhere else, over a much, much larger surface area.
2. Whether or not the Arctic Ocean is connected to the remainder of the oceans physically (“not independent”) is not relevant if we are calculating global OHC. You just add the numbers.
Kevin, Al: What does basic physics tell us about water vapor in the Arctic in the winter? It tells us that evaporation is very limited if the air temperature above an ice bath is, say, minus 20C, right?
As I’ve pointed out before, what happens in the Arctic is strongly affected by input from outside the circle. If a storm brings in warmer air, you get water vapor and clouds, or if a warmer ocean current intrudes. But if you think about it as an isolated part of the climate system, what would cause it to “warm up” would be the increase in CO2. And yes, the increased insolation in summer would then gradually speed things up.
The problem, though, as I’ve also pointed out before, is that people get all excited about short-term changes in extent, when there is no physical mechanism to create a “tipping point”. Such an event would require that external input by advection from the south.
Jay at 19 says “You all need to start appearing on the media and fighting back against the oil lobby. I’ve been following this on and off for the last 12-13 years but it’s not reaching the masses. Go post on fox news comments to fight against their misinformation…”
Hey, Jay
Why don’t you shoulder this workload? We post and discuss climate in a somewhat fractious environment here at RC. For my part, I just don’t need the frustration of dealing with the social media idiots on less thoughtful platforms than RC. I am sufficiently frustrated by the lukewarmers and “voice of reason” types who provide a little pushback here.
I also think there is some reactionary impulse that happens in those other setting that is unfortunate and counterproductive as well where as we attempt to reason with the denialist community, they respond to the push and info by doubling down on denial. Sometimes it makes sense to step back and create a vacuum where the deniers move your way as you withdraw instead of trying to engage and pull them your way as they dig in their heels/stick to their guns, etc. The culture wars just aren’t for everyone, you know? We all do what we can, where we can, how we can.
Cheers,
Mike
Mike
@kevin McKinney, #17
“ If you wanted the planet to warm as fast as possible, you’d be cheering for lots of winter cloud (especially at higher altitudes)……”
Yes, clouds and GHG’s act as insulation between relatively warm ocean water and the extreme cold of space, but so does ice! The ice cover is like a lid…..take it off and ocean heat escapes to the atmosphere at a faster rate than before. My hunch is that a more humid, cloudy atmosphere (more insulation) does not compensate for loss of ice cover (less insulation), in terms of OLR.
“…. but for sunny late summer skies, when the water can absorb all that sunshine.”
All that sunshine??? There’s a ton of sunshine around the start of summer (solstice), but drops off to near zero near the end of summer (equinox), when extent is at its lowest:
On the June solstice 36% more solar radiation reaches the top of the atmosphere over the course of the day at the North Pole than at the Equator.[2] However, in the six months from the September equinox to March equinox the North Pole receives no sunlight.
********
This is what I’d like to see:
A) a time series (full satellite record) of OLR above the Artic during the dark months.
B) a time series of the annual energy budget at the TOA over the Arctic (again, full satellite record).
@Al Bundy #18
As you know, an increase in GHG’s represents more insulation, warming the planet, but as mentioned in my response to Kevin, loss of arctic ice might represent the opposite – a decrease in insulation, with an overall cooling effect.
Sorry, this was supposed to be in quotations, and came from Wikipedia:
“On the June solstice 36% more solar radiation reaches the top of the atmosphere over the course of the day at the North Pole than at the Equator.[2] However, in the six months from the September equinox to March equinox the North Pole receives no sunlight.”
https://en.m.wikipedia.org/wiki/Climate_of_the_Arctic
Thank you for updates on the Nenana Ice Classic. Records are tumbling in the region–along with ways of life and survival. Here’s a newly reported sign of Antarctic change–to a significant piece of the face of deep time in Antarctica. Different place, different signal, notable in its own particular way.
Dr Trathan said: “What’s interesting for me is not that colonies move or that we can have major breeding failures – we know that. It’s that we are talking here about the deep embayment of the Weddell Sea, which is potentially one of the climate change refugia for those cold-adapted species like emperor penguins.
“And so if we see major disturbances in these refugia – where we haven’t previously seen changes in 60 years – that’s an important signal.”
https://www.bbc.com/news/science-environment-48041487
Snape:
Indeed. But the drop-off isn’t linear; the main determinant is day length, not angle of declination (though that does have an effect). And for the high Arctic, there is still lots of sun around the time of the fall equinox.
See this; it’s not as directly on point as I’d like–the search gods aren’t being kind to me just now–but does illustrate.
For 90N, “187 days of 24 hour sunlight, 163 days of 24 hour darkness.”
http://www.arctic.uoguelph.ca/cpe/environments/sky/features/sun_moon/daylight.htm
Also:
http://www.athropolis.com/sun-fr.htm
Per the last, for September 23, 90 N gets 24 hours of sun (but it sets for the winter the next day); at the Arctic Circle, there is (of course) just more than 12 hours of daylight. (12 hours, 18 minutes, to be precise.)
Zebra, at #20
“1. Low extent in the Arctic increases radiation to space. But, that fact by itself tells us nothing about whether global OHC increases or decreases during that time period, because there is radiation and absorption going on everywhere else, over a much, much larger surface area.”
It tells us that if global OHC increased during that time period, it may have increased even more if not for low extent in the Arctic. It tells us that if global OHC decreased during that time period, a small part of the decrease may have been due to low extent in the Arctic. I’m well aware, Z, that if one stock in the Dow moves up, that movement may not be reflected in the index as a whole. It would be nice if you could read between the lines a little, rather than looking for something to criticize.
2. Whether or not the Arctic Ocean is connected to the remainder of the oceans physically (“not independent”) is not relevant if we are calculating global OHC. You just add the numbers.
Add what numbers? Radiatively cooled Arctic water does not necessarily stay in the Arctic. Warmer water, from the Pacific and Atlantic mix in as well. This means that whatever effect low extent has on Arctic OHC, warming, cooling or neither, is muddied by neighboring oceans, and not easily quantified.
@Kevin McKinney
Thanks for the links, probably better than the ones I found. You’ve undoubtedly seen a graphic like this:
https://earthobservatory.nasa.gov/global-maps/CERES_NETFLUX_M
……where we see the poles have an annual net deficit at the TOA (not surprising, of course). I’m just wondering if that deficit has increased or decreased as a result of ice loss. My bet would be the former, but pure speculation.
#27 Snape,
“looking for something to criticize”
Snape, pointing out that something is wrong is what people here do all the time; whether it is a Denialist meme or misdirection, or confusion about scientific facts and principles, or poor communication.
The goal is to educate the hypothetical sincere lurker about climate change, and science and reason in general. For my part, I welcome rational disagreement, if the other person explicitly explains their reasoning. That’s how we learn and refine our own thinking.
Science is all about clearly and precisely articulating how something works, and then taking responsibility for getting it wrong, as well as taking credit when you get it right.
Why don’t you try taking some time to read over what you write and see if it makes sense in its context before you post it? Your last paragraph, for example, makes no sense as a response to what I said.
Zebra,
“Science is all about clearly and precisely articulating how something works, and then taking responsibility for getting it wrong,”
Thanks for setting me straight! I thought science included making observations, forming hypotheses, testing them – stuff like that. (or maybe my interpretation of the comment was too literal, and I should read between the lines a little?)
Any info on Antarctica ice outs?
I’m kind of a fan of the younger Broecker and his ocean circulation hypotheses. 38 sec. of History Channel
https://is.gd/7vQ8Nq
#28, Snape–
Thanks in turn. A detail I found interesting: over the Greenlandic and Antarctic ice sheets, you basically never see a net positive radiation balance. Too high an albedo, I expect: “Energy goes out in two ways: reflection by clouds, aerosols, or the Earth’s surface…”
Which, of course, is why the “dimming” of the Greenlandic ice is concerning.
https://eos.org/opinions/what-darkens-the-greenland-ice-sheet
#30 Snape,
“observation, hypothesis, testing”
A naive description– sounds like what people learn to memorize in middle-school science class.
Consider what actual scientists do in order to do science:
1. Demonstrate that they are knowledgeable and competent with the current state of the art, by taking difficult undergrad courses and passing tests.
2. In grad school, propose a thesis and then defend it under questioning.
3. Having the degree, it is then necessary to write a proposal to convince people that expenditures of someone else’s money is justified, in order to do research.
4. Having the funds, it is then necessary to produce a paper which passes peer review.
5. After being published, it may be necessary to defend conclusions from questions of theoretical soundness and replicability.
And of course, rinse and repeat 3,4,5.
You appear to think like the Denialists, who say silly things like “science isn’t about consensus”, and that any claim made on the internet is as valid as any other claim, as long as some random other people like what you are saying.
For example, reading between your lines, it appears that you think your comments about global OHC should be considered even though you admit to not knowing what numbers are used to determine it.
The positive thing about the Internet is that it allows us to read up a little on such subjects without much effort, beginning on actual scientific sites like NOAA. But you have to at least put in that minimal time in order to form an opinion that can be rationally defended.
Zebra
We are having a hard time communicating. For example, you wrote,
“You appear to think like the Denialists, who say silly things like “science isn’t about consensus”, and that any claim made on the internet is as valid as any other claim, as long as some random other people like what you are saying”, couldn’t be further from the truth.
I like to speculate about various subjects within climate science. It’s good fun and I learn a lot in trying to support my position. But being aware of my own lack of expertise, I make a point of NOT challenging the consensus, the IPCC being the benchmark in my mind. I try to limit my speculation to areas where I think there is NOT yet a consensus, fully aware that whatever ideas I have, or those of other non experts, need not be taken too seriously.
@30/@33
It never ceases to amaze me/make me laugh when obvious amateurs lecture professionals on how to do their job. Doesn’t matter if it’s professional sports or professional science or any other profession.
@Kevin #32
There’s an albedo issue that hasn’t received much attention – snow cover extent. The Northern Hemisphere has seen a large decline during late spring and early summer, the period when solar insolation is at its peak:
https://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6
Snape @34
Everyone has a hard time communicating with Zebra. You have my sympathies!
#36, Snape–Yes, that reduction in ‘peak sun’ NH snow extent has to be a significant climate feedback. I wonder if anyone has tried to quantify, for example, just what proportion of the observed ‘Arctic amplification’ it’s responsible for? Maybe not as much as the water vapor feedback, but still quite a lot?
I am surprised that none of the science types has commented on Karsten Johansen’s post on April 18th (#11). Is he describing a real measure here?
@nigelj
I’m glad to hear it’s not just me. It feels like Zebra and I could get into a never ending argument, nothing to do with climate science, “No, somewhat random is very different than somewhat pregnant! “
“I am surprised that none of the science types has commented on Karsten Johansen’s post on April 18th (#11). Is he describing a real measure here?”
ozajh, Boreholes are used for measuring thermal diffusion coefficients of different types of earth, i.e. topsoil, clay, etc. A heat impulse is injected into a borehole and remote sensors trace the relative rise in temperature. So it’s a real measure and has utility for heat exchangers used in geothermal heat pumps (we describe the math of thermal diffusion here https://agupubs.onlinelibrary.wiley.com/doi/10.1002/9781119434351.ch14)
#39, ozajh–
Yes, borehole measurements are a ‘thing.’ (In fact, that’s what the repository of dopey comments here at RC is named for.)
For example:
https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/borehole
Google will turn up much, much more.
@Kevin
I typed in “snow cover extent albedo” and found several studies and lots of information. At the top was this from the NSIDC:
“Northern Hemisphere Snow
We all associate snowstorms with cold weather, but snow’s influence on the weather and climate continues long after the storm ends. Because snow is highly reflective, a vast amount of sunlight that hits the snow is reflected back into space instead of warming the planet. Without snow cover, the ground absorbs about four to six times more of the Sun’s energy. The presence or absence of snow controls patterns of heating and cooling over Earth’s land surface more than any other single land surface feature.
In many locations in recent decades, temperatures have risen while precipitation levels have remained largely the same. Satellite data have confirmed that average snow cover has decreased, especially in the spring and summer. Where snow cover is disappearing earlier in the spring, the large amounts of energy that would have melted the snow can now directly warm the soil.”
https://nsidc.org/cryosphere/sotc/snow_extent.html
Snape et al.,
First, somewhat random is exactly like somewhat pregnant in that neither concept exists. A process, series, sample… is either random or it is not.
Second, consensus is critical in the scientific method. However, it is nothing like a poll. Rather, scientists “vote” by their decision to use a theory, technique, etc. in their research. If a scientist uses GPS in their research, they believe in relativity and a quasi-spherical Earth regardless of what they claim. Eventually, you get to the point where a concept, theory, etc. is so critical to understanding a field that those who truly reject it have nothing useful to say–and as far as peer-reviewed research, they STFU.
Eventually, you get to the point where a concept is so critical to understanding multiple fields that it is supported by many diverse, independent lines of evidence–a stage Ed Wilson calls “consilience”. Overturning a theory at that point is literally a scientific revolution.
#43, Snape.
I was keenly aware of the reflectivity of a snowfield this spring in MN, when our very snowy February and March left us with a lot of white. My thoughts were a product of reading the AIP history of the field, as the stubbornly cold later spring had me thinking how easy it would be to slip into glaciation in the absence of our CO2 surge. What a feedback all that reflectivity is.
@Ray, #44
I like to use asterisks to separate one topic from another. How many do I use? Well, it’s a somewhat random number, sometimes 4 or 5, sometimes 6 or 7. I don’t count.
Is the number totally random? Of course not! 347 asterisks, for example, would be way too many.
******
Climate scientists disagree over hypotheses like the “lazy jet stream”.
“However, not all research supports Arctic amplification and its impacts on mid-latitude weather patterns. For example, Screen and Simmonds (2013) tried to link the two through planetary wave patterns and did not find any clear trend. And recently, Barnes (2013)found no significant increase in the frequency of blocking events over North America and the North Atlantic, indicating that severe mid-latitude storms cannot simply be understood through Arctic amplification alone. This research does not mean that Francis and Vavrus’ hypothesis is wrong, it simply means that the atmosphere is complex and more research is needed.”
https://amp.theguardian.com/environment/climate-consensus-97-per-cent/2018/oct/15/theres-one-key-takeaway-from-last-weeks-ipcc-report
I’m not qualified to take sides, and therefore go with the opinion of the IPCC, which as far as I know has taken a wait and see position. A little speculation while waiting for a consensus? Sure, but I don’t take my guesses too seriously and don’t expect anyone else to.
#44 Ray Ladbury,
Good description. Discussions like this often lead to memories and clarity, and of course more questions. The memory popped up of trying to research a paper in high school:
-It involved taking the subway to the main library in Manhattan.
-It involved leafing through card catalogs.
-It involved searching for a book, often mis-returned to its place on the shelves.
-It involved reading and understanding, and taking notes on index cards.
-It involved copying down the references given, going back to the card catalog, sometimes having to go to the reserve desk, or going back to the shelves to find the book and take some more notes… on index cards.
-It involved sorting out which books would be the most useful, checking them out, and trying to manage them on the subway back home– backpacks were not in vogue then.
-Then there was the hunting and pecking on what we called a “typewriter” (look it up, kids) to produce the final result, and then perhaps doing it all over because there was no cut-and-paste to rearrange things. And so on.
Anyway, it made me wonder about how much the conception of what counts as knowledge and understanding has changed. Certainly it has among the general public; now we have:
-typing in some word
-getting a hit
-a cursory reading, no education/background required
-forming “an opinion”
-firing off a comment
-and, obviously, if you don’t end up in the borehole, that’s equivalent to peer review…
I’ve always seen the development of information technology and the internet as positive, but back when I was trying to early-adopt it for education, I assumed that it would be incorporated into an experience-based process. Now I am not so sure that it hasn’t changed the paradigm– maybe there is much more of a divide between the people who do actual science and engineering and the people who use the results.
Regarding all this Snape & Zebra stuff on the jet stream.
Everything about global warming suggests to me it would cause the jet stream to wobble around. I’m no climate scientist but I can see the dynamics of it. M Mann has a strong position it is related to rossby waves. But theres no good consensus or trend just yet like Snape says. Wait and see it could change anytime. Just like recent research papers have provided compelling evidence the AMOC has slowed.
There was no statistically significant warming for a while after 1998, which was frustrating because it fed the denialists and there certainly looked like there was warming, then that all changed from 2015.
If we start saying there is a relationship because the science says there should be a relationship we could fall flat on our face. There most likely is a relationship, but it needs better evidence to confirm this, to be absolutely sure. Everytime scientists take shortcuts and make sweeping conclusions, or over catastrophise, it feeds the denialists. The IPCC reports might be a bit conservative, but they are solid and quite scary enough without having to get carried away and ending up looking like headless chickens.
@48
The statement “There was no statistically significant warming for a while after 1998” has been well and thoroughly debunked from the statistical perspective.
The statement depends on violating a number of assumptions required to make a statement of “statistical significance” starting from the cherrypick of a local max in a time series and going on from there. One might as well try to argue finding a string of 6 heads in a row in 100 flips is statistically unlikely because the odds of flipping 6 heads in a row is .016. It is simply incorrect statistical reasoning.
Tamino, for one of the best examples, has gone into this in great detail so no need to discuss this further. https://tamino.wordpress.com/2018/12/19/global-warmings-pretend-pause/ (see references there to other discussions, papers, and previous blog entries).