Arguments
Global cooling - Is global warming still happening?
What the science says...
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All the indicators show that global warming is still happening. |
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Climate Myth...
It's cooling
"In fact global warming has stopped and a cooling is beginning. No climate model has predicted a cooling of the Earth – quite the contrary. And this means that the projections of future climate are unreliable." (source: Henrik Svensmark)
At a glance
Earth's surface, oceans and atmosphere are all warming due to our greenhouse gas emissions, but at different rates. Some places are also warming much faster than others: parts of the Arctic for example. That variability is partly because other phenomena act to offset or enhance warming at times. A good example are the effects of La Nina and El Nino, an irregular variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean that can influence temperatures and rainfall patterns right around the world.
El Nino causes even warmer years whereas La Nina tends to peg temperatures back to an extent. Thus 2023 – an El Nino year - was the warmest year on record, according to the USA-based National Oceanic and Atmospheric Administration, but other recent years have not been far behind – 2016 and 2019 are in second and third place respectively. The worrying thing is that 2019 only saw a mild El Nino. And even with a La Nina featuring, 2021 and 2022 were, respectively, still the seventh and sixth hottest years on record.
The year 1998 featured a massive El Nino and consequent temperature spike that was a strong outlier, well above the steady upward trend. That spike and the subsequent return to a more “normal” warming pattern led to claims in the popular media that global warming had “paused” or had even stopped. This was a typical misinformation tactic that, as usual, time has proved wrong. As things currently stand, the top ten warmest years have all been since 2010 and 1998 is nowhere to be seen any more. By modern standards, it simply wasn't warm enough.
Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!
Further details
In the years following 1998, at the time the hottest year on record, there was a concerted misinformation campaign to convince the public that global warming had variously slowed down, stopped or even that we were entering a period of cooling. Of course, we now know that such claims were nowhere near correct. In today's top ten ranking of warmest years, the year 1998 is nowhere to be seen. It simply wasn't warm enough. So let's take a look at how the claims came about, because they reveal insights into the methodology of those who design and spread misinformation.
The entire planet continues to accumulate heat due to the energy imbalance created through our greenhouse gas emissions. Earth's atmosphere is warming. Oceans are accumulating energy. Land absorbs energy and ice absorbs heat to melt. Year to year ups and downs in these things are simply noise, reflecting variations in how that heat is moved around the planet and what other influences are at work, such as the irregular El Nino Southern Oscillation (ENSO) that can nudge the global temperature one way or another by up to 0.3C. That's why 1998 was such a warm outlier: it coincided with a very strong El Nino. El Nino conditions always warm things up whereas La Nina conditions cool things down (figure 1).
Figure 1: GISTEMP anomalies to end-2023 (with respect to late 19th Century), coded for ENSO state in the early spring - red is El Nino, blue La Nina. 2023 is in grey because that El Nino did not develop until later in the year. Graphic courtesy of Realclimate.
Climatologists routinely use multi-decadal blocks of time when presenting temperature trends for a very good reason. Such blocks allow you to stand back and look at the bigger picture. Due to the noise, taking a much shorter time-span – say just five or ten years – allows you to say anything you like about trends, depending on the particular block you pick.
For example, if you picked a short run of 5-10 years ending in 1998, you could have – if you were so inclined – said, “look how fast it's warming!” Likewise, taking a number of years starting with 1998, you could have made the equally invalid claim that global warming had stopped. And of course, that claim was made, vociferously, in the early-mid 2000s. It was a classic example of cherry-picking: the manifestly unscientific practice of choosing the data that supports the argument one is paid to make on behalf of those who sponsor misinformation campaigns. Once you know about such tricks, you can challenge them yourself. You can ask someone why they showed such a short temperature record when showing a much longer one is the normal practice.
It is difficult but technically possible to filter out the noise described above from temperature datasets. In the paper Foster and Rahmstorf (2011) the authors used the statistical technique of multiple linear regression to filter out the effects of ENSO, solar and volcanic activity (Figure 2). They found that the underlying global surface and lower atmosphere warming trends have in fact remained steady in recent years. There's still noise in there but nowhere near as much. We were still warming all along.
Figure 2: Five datasets of global surface temperature and lower troposphere temperature are shown before and after removing the short-term effects of the El Niño Southern Oscillation (ENSO), solar variability, and volcanic aerosols. A 12-month running average was applied to each dataset.
Last updated on 4 June 2024 by John Mason. View Archives
jetfuel @223 writes:
"I'm looking for an anomoly where it is much warmer in the Arctic in the winter so as to cause a once in decades event"
Let's ignore the fact that the cold North American winter was not a once in decades event, but an almost commonplace winter as little has half a century ago; and has only become exceptional by comparison to recent warmth.
Rather, let's focus instead on the unusual situation where jetfuel claims to be looking for anomalous warmth, but does not bother looking at surface temperatures to find that anomalous warmth:
(Gisstemp polar authographic projection of 2014 winter temperature anomaly.)
We'll also not ignore the fact that the theory jetfuel is criticizing is that reduced sea ice extent in late autumn creates greater warmth in the Arctic, destabilizing the jet stream resulting in unusually cold early winters. Therefore references to March sea ice extents, sea ice volume and (most especially) Antarctica are all red herrings. What he should be looking at is the November sea ice extent which was the sixth lowest on record. That was only 6.8% below the 1981-2010 average, but that period (1981-2010) shows continuous decline so that it was much more than that below the 20th century average.
jetfuel @225.
You appear to be asking a rhetorical question - "This didn't have anything at all to do with this last very cold winter?" What is still a mystery to me is which winter you are trying to refer to. 'This last winter' was not 'very cold' for an Arctic winter. Indeed, it was rather warm. (See this graphic of Arctic Ocean Lower Troposhpere Temperatures - usually 2 clicks to 'download your attachment'.) Nor was the previous winter (2012/13) particularly cold. What was cold was the Arctic summer & autumn of 2013.
Given such circumstance, the use of your rhetorical question appears to be misplaced. Indeed, you point out yourself that extra ice volume is due in part to the "retention of thick, multiyear ice", a situation more associated with low levels of melting than with high levels of freezing which sort of fits with the Arctic temperatures over recent seasons.
So is your use of the term "winter" correct and if so which winter are you attempting to refer to?
2011-2012 winter was hardly a winter. 2012-2013 was normal for winter. 2013-2014 was setting all kinds of records in Indiana. We just broke a record for fewest 70 degree days by late April that stood for 99 years.
Warm air always blows up into the Arctic. whether it stayed there or not this past winter, it formed over 11 million sq km of new ice between Sept 2013 and March 2014, and while that was happening, the Arctic is so unusually warm, that it splits up it's cold air mass and smaller pockets drift down over Canada, Indiana, etc. So this year the bad news is: it's negative 25 instead of negative 35 at the North Pole while a new record is set for newly formed seasonal ice area increase throughout the Arctic?
"One thing that is pretty clear is that the cause-and-effect chain for any changes won't have just two links in it" This is exactly why the Polar Vortex narrative that followed 2 days of media silence on Jan 24th this year, used to explain why we were having a normal 1900's winter, and so universally pushed on me by the media, has me agreeing with this quote and all this PV narrative. If the north pole fell apart in January, then as winters and summers have gotten colder where I live over the last 30 months, it seems that just the opposite is happening. Something about warmest Arctic air causes nearly most ever, if not most ever, ice to form during the same time doesn't sound right. And now I'm told that the PV breakup is common pattern? This was the most uncommon winter since 1993-4 here. What recent year exhibited this same PV disruption?
[JH] Please specify the geographic that is covered in your characterization of recent winters. Is it North America? The entire Northern hemisphere?
You also state: This was the most uncommon winter since 1993-4 here. Where is "here"?
jetfuel @228.
You say "....it formed over 11 million sq km of new ice between Sept 2013 and March 2014." I do not recognise that figure. Using NSIDC monthly data, Arctic SIE rose 9.45M sq km. Daily SIE data from JAXA increases this slightly to 9.64M. Daily SIA yields a yet larger number - 9.92M - but none of these nmbers are "over 11 million sq km" and none of them are "a new record."
I am therefore entirely perplexed as to what it is you think you are about with these numbers you present here. Explain yourself - if you can.
jetfuel, frankly speaking your sense of personal incredulity about what is going on is not a sufficient substitute for analysis based on the available evidence. Especially not when you are backing that up with sea ice numbers that appear to be coming out of thin air.
I should like to reiterate Tom Curtis' point that winters that are exceptional in the 1990s through the present were once a commonplace, and as such by over-stating their importance you are falling for the shifting baselines fallacy.
I must make a special note about:
Well, yes. Because in the 2010's a "normal 1900's winter" is exceptional and requires an explanation.
Also, this year's sea ice maximum extent was the fifth lowest in the satellite record. What is more, the seven lowest maximum extents have all occured in the last seven years.
And, now that I've noticed it:
First, citation please. Second, what of it? A small region on the Earth is very likely to see much more variability in its temperature trends in 30 months than it will in, say, 30 years (which is the usual standard for establishing temperature trends in climate).
jetfuel @228, it is not part of the polar vortex theory that the large southern excursions of the polar jet stream that brings unusual cold for the 21st century will always occur over Illinois. On the contrary, it is a chaotic process, and can at any longitude. Thus, in 2011 it occured over Europe, and weakly over the US eastern seaboard:
In 2012 over the extreme eastern region of Siberia:
In 2013, over the Siberia, Mongolia, China and Japan:
And as already seen, in 2014 it occured over the majority of the contiguous US.
Further, the theory is not that similar events have not occured in the past. Rather, it is that the warmer Arctic ocean makes such events far more likely.
If you are going to criticize a theory, you need to actually read the theory in the scientific papers, and make sure you understand it. If not, you will inevitably end up criticizing a straw man. You can start with Honda et al (2009), which discusses the connection specifically with connection to Eurasia, and Liu et al (2012) , which extends the theory to include the US.
Geographic area: Central Indiana, Yes, sorry, I did have the last two winters switched for ice area growth. The second to last season was the one with over 11M of increase.
All from nsidc: In Sept 2012: 3.425M sq km ice area. In Mar 2013 peak day: 15.10M sq km. 15.1-3.425=11.675M sq km increase. I will eventually learn how that compares since 1981. Then after that huge increase, the following winter saw only 15.229-5.1=10.129M sq km. Sorry I had the two years confused with each other. Still, one would think that both years are normal or above normal ice increase (10.129 and 11.675 million sq km). For instance, Sept 23, 1997 to March 1998 increase was only 9.328M sq km of increase, and that was one of the the coldest recent winters, peaking at 15.955M sq km of ice area.
Warmest Arctic air in a while causes nearly the most ever (10.1M), if not most ever (possibly the previous year with 11.675M), sq km of ice to form during the same time puzzles me as to why the warm air didn't stunt ice growth comparatively.
Records, records, and more records: from mlive.com: clarifies my earlier estimates:
"Lake Superior is still over 60 percent covered in ice as of yesterday Saturday April 26, 2014. The satellite pictures shown above were the latest I could find that had clear skies and good vision of the ice. These high resolution satellite images come from April 23 and April 24, 2014.
On Wednesday April 23, 2014 Lake Superior had 68 percent ice cover. According to the Great Lakes Environmental Research Laboratory, the previous highest amount of ice on that date was in 1979 when there was 38 percent ice cover.
So the ice on Lake Superior is currently almost twice as much as recorded for this late date in the ice season. The records go back to 1973.
On Wednesday, Lake Michigan still had 15 percent ice cover. The highest amount in the records on that date was five percent in 1979. This means Lake Michigan has three times the previous highest ice amount on April 23.
Lake Huron was still reporting 25 percent ice, with the previous late season high at 11 percent in 1996."
I learned that while area never eclipsed the 1979 mark, the lasting of ice was the highest on record. This tells me that possibly the volume of ice was surely a record since accurate records of area started in 1973. Some said 2014 was going to be the summer of zero Arctic ice. It may turn out to be the summer of June Lake Superior ice. In other news media statements, I'm led to believe that I live in the only part of Earth that is cooling over last 30 months. US Midwest.
[JH] Posting a potpurri of factoids is akin to sloganeering which is prohibitied by the SkS Comments Policy. Future posts of this nature will be summarily deleted.
Since you have repeatedly posted poturris of factoids, you are also engaging in excessive repititon which is also prhobitied by the SkS Comments Policy.
You are now skating on very this ice indeed.
jetfuel wrote "All from nsidc: In Sept 2012: 3.425M sq km ice area. In Mar 2013 peak day: 15.10M sq km. 15.1-3.425=11.675M sq km increase. I will eventually learn how that compares since 1981. "
perhaps you should perform this analysis before making claims about how unusual the increase is. Now had you been paying attention to the replies to your comments, you would know that the answer has already been pointed out to you more than once. Here is the important graph:
The increase isn't that dramatic compared to previous years, and is due to the fact that winter maximum is declining a bit more slowly than the summer minimum (for fairly obvious reasons). However the trends in both are downwards. Look at the trends, not the noise.
DM @234, the graph you show shows almost no trend for sea ice extent maximum. It also shows sea ice extent maximums substantially less than the March average sea ice extents from the NSIDC:
As the link to the image you use mentions Goddard, how sure are you of its reliability?
In any event, here is the EEA arctic SIE analysis for Nov 2012 (there most recent), which has the advantage of showing the trend lines:
As can be seen, the trend for both March and September are both negative, but the absolute value of the September trend is more than twice that of March. It follows, as you point out, that the sea ice extent recovery increases, on average every year.
It is very clever of jetfuel to turn evidence of decreasing sea ice extent at all times of year into proof that the Arctic is cooling /sarc
Dikran, I looked at the NH min sea ice trend you predict. It looks like a good fit, but 2013 (not incl) bounced back to the very upper limit of grey shaded area (@5.1M) and 2014 will have to be less than 5.1M min for the 95% CI to continue to match. Your graph ends with 2012. The 2012-2013 recovery reasonably matches the largest of any shown, that of 1997-8. Looks like 2032 is the min=0 prediction without 2013 data included. I presume this chart will be redone if Sept 2014 min exceeds 5.1M?
jetfuel @236, here are the relevant figures taken from the NISDC, and converting the percentage trends given by the NISDC to trends in area for ease of comparison:
From this it is easy to sea that we expect the 2013-2014 to be one of the largest known based on comparative trends alone. We expect 2012-2013 to be the largest, or very close to the largest known, because the September 2012 sea ice extent was the lowest ever known and March sea ice extents do not decline as fast as September sea ice exents.
You are, to put it bluntly, trying to convert evidence that both summer and winter sea ice extents are declining, but the winter sea ice extent is declining slower into evidence that the sea ice extent is recovering (ie, growing larger). You now have all the relevant facts before you in a very clear fashion. Persistence in your obsession on this point will merely prove you to be an utter fool, or dishonest. Consequently if you fail to respond acknowledging this point, I will strongly recommend to the moderators that you be barred from SkS on the grounds of persistent sloganeering.
TC, in #235, The trendline looks OK. .0447M km2 per year shown as straightline decline of maximums and so an 11.675 M increase in one seasonal swing 2012-13 is 261 times the .0447M/yr decreasing trend. I added in sept 2013 and sept 2014 since they are now on the books and could draw a last 11 year trend line with a positive slope for maximums.
How I get 11.675M for sept 2012 to Mar 2013: Was this ever exceeded before?
... wait, what?
Jetfuel
"Was this ever exceeded before?"
No...and by saying that you are essentially agreeing with the point that Tom and DK are making. Let's make sure this is clear. Summer sea ice minima and winter sea maxima in the Arctic are both declining. Because the decline in summer ice minuma has been faster than the decline in winter sea ice maxima, a record low summer minimum is very likely to show a record seasonal increase in sea ice extent. Rather than suggesting that sea ice is recovering, the large seasonal increase means that more and more of the ice at the start of spring melting season tends to be thinner first year ice, which tends to melt more readily the following summer, contributing to larger seasonal variation.
"...a last 11 year trend line with a positive slope for maximums."
Why 11 years? Why not 20? Or maybe the whole length of the data set? Can you show that the trend of the last 11 years is statistically different than the entire record?Before you try, I'd point out that the 2014 arctic sea ice maximum in the NSIDC graph presented by Tom falls almost exactly on the long term trend line.
jetfuel
I'd like to add that in all your interactions so far, you've tried to find ways to make the data say what you appear to want it to say, rather than engaging in an honest give and take about what the data actually says. This is a one way street at present, with commenters here providing helpful context, and you, so far, largely ignoring them to push your predeteremined interpretation.
Look, no one (and I really mean nobody) I know is happy about what these data imply, but the tale they tell is very straightforward. Arctic sea ice is melting, as we would expect giving warming sea and air temperatures. It's just not that complicated. If you have to do intellectual summersaults to say otherwise, that is a giveaway that you are arguing a losing case.
BTW...I meant DM in the previous post...not DK.
jetfuel, another thing to keep in mind is that the Arctic is largely land-bound. Sea ice growth is limited by land. Summer ice is free to drop according to climate (troposphere/surface/ocean) conditions. Winter ice is free to grow southward only up to a certain point. If winter growth were unfettered, the winter max would be much larger, especially earlier in the record, and the negative trend would be much steeper.
Another way to think about this - imagine what happens when the artic is ice-free in summer. The "recovery" in winter is even larger - because the oceans will have to warm a great deal before a sunless sea will not develop a layer of thin ice on top. But this is not "recovery". Recovery is when there is more ice at a particular time of the year than at the same time in other years.
Jetfuel wrote "Dikran, I looked at the NH min sea ice trend you predict.It looks like a good fit, but 2013 (not incl) bounced back to the very upper limit of grey shaded area (@5.1M) and 2014 will have to be less than 5.1M min for the 95% CI to continue to match."
That was not the result to which I directed your attention, as I suspect you are fully aware. I was directing your attention to the fact that sea ice extent is decreasing more slowly in March than it is in September, which explains why we expect the annual increase to be increasing. The reason I showed the graph that I did in my previous message was you make sure you knew what part of the post was relevant. In disregarding this, you have given a strong impression that you are not interested in the truth and are just trolling.
"Your graph ends with 2012. The 2012-2013 recovery reasonably matches the largest of any shown, that of 1997-8. Looks like 2032 is the min=0 prediction without 2013 data included. I presume this chart will be redone if Sept 2014 min exceeds 5.1M?"
Again you are just avoiding acknowledging that an increasing recovery is exactly what we would expect, i.e. you are trolling.
See Toms' excellent post for a further illustration of this.
Do you accept that we should expect an increasing trend in the recovery from the September minimum to the March maximum. Please give a straight answer, yes or no.
I thinkthis graph well illustrates the point that all this blather about "record freeze" is away with the fairies.
The black line is the increase in Arctic SIE from minimum to maximum. The blue line is the March SIE displaced for reasons of comparison. It is very evident this maximum has no significant bearing on the black trace. And it is evident from the red trace that the minimum, the outcome of the previous melt season, has everything to do with it.
I hope I didn't make it more complicated than kerosene.
All: A friendly reminder — Dogpilling is prohibited by the SkS Comments Policy.
All: Please do not immediately respond to jetfuel's next post. I would like to review it and determine whether or not it constitutes sloganeering and/or excessive repetition. If it does, the comment will be deleted.
I will respond to jetfuel's most recent post tomorrow, after JH has had a chance to review it, as requested.
[JH] Thank you.
jetfuel's most recent post violated three SkS comment restrictions, i.e., no sloganeering, no excessive repetition, and no moderation complaints. His comment was therefore zapped.
US natural gas supplies are at an 11 year low. Jeffrey Folks article on American Thinker: "A recent report on natural gas usage during this past winter. For the first time, the U.S. burned more than 3 trillion cubic feet of natural gas this winter, most of it for heating. That was more than the 2.3 trillion cf of 2012-13, and double that of 2011-12.
That evidence is irrefutable. We have lived through a winter of historic proportions – the coldest winter in Vermont’s long history, and the third-coldest for the city of Chicago. Gas futures also provide evidence about next winter.
Futures traders are highly sophisticated investors who base their trading on all known information. Futures traders care only about the facts. When they are right about the facts, they stand to make a great deal of money."
I took a survey on CO2 and found out a few things: I generate 4.6 tons of it per year. Unfortunately, the site told me my result was above the world average of 4.0 tons, and that we 6.6 Billion Earth inhabitants need to all cut back to an average of 2 tons each to stabilize current global CO2 levels. For me to get down to 2 tons, I need to bump my 32 mpg sedan up to 70 mpg without any factory participation and turn my house from 66 degrees down to about 50 degrees all through next winter, and set my a/c on 85 this summer. Then, if 6.6 Billion others each also cut their use in half, Moana Lau can hold steady at 401 ppm CO2.
Not going to happen, but the US is reducing CO2 production by 7% per year and we make about 7% of the human made CO2 in the world. I wonder how our 3 trillion cu ft of nat gas use compares to our gasoline use.
[JH] Stop wondering and start researching. Google can be your best friend.
@jetfuel It may have been a harsh winter in Vermont, however it was an unusually mild one in the U.K. However the plural of anecdote is not data. If you want to make an argument that it is cooling, fine, but present the data supporting your argument, not just cherry picked press stories.
As to Arctic sea ice extent. There are a variety of reasons that the annual "recovery" is increasing. The most obvious is that it is dark during much of the winter in the high Arctic and any open water is likely to freeze up. The smaller the September minimum, the more open water there is, the more first year ice will form. This isn't rocket science. As to why the March maximum is declining more slowly than the September minimum, I'd say it was a combination of at least two factors. Firstly it is dark in the high Arctic during much of the winter, so the "regional" greenhouse effect is relatively small as the Sun is not warming the surface. Secondly, when the ice pack is relatively solid during the winter, it will be less affected by Arctic weather, principally wind which pushes the ice about more in the summer when it is broken up, rather than more or less contiguous during the winter.
[JH] Excellent advice. Unfortunately, jetfuel is unlikley to take it because he has been ignoring such advice since he began posting comments on SkS. I suggest that everyone completely ignore what jetfuel posts from here on out. I have recommended that jetfuel's comment privileges be rescinded.