Global Surface Air & Sea Temperatures: Current Conditions and Future Prospects

[WYorksWeather]

14 minutes ago, reef said:

I think what will be interesting to see over the next few years / decade is whether the current jump in warmth is temporary and if we return to trend (currently around +1.1 - 1.2C) or if we've gone through a step change and see an acceleration in the temperature rise.

I don't think trend warming is as low as 1.1-1.2C. The 2020-2022 saw global temperatures around those levels, but that's in the presence of a moderate to strong La Nina, so the trend without ENSO has to be higher than that.

So, base case is probably that trend warming is in the range 1.2-1.3C at the moment. This would then conform with pre-2023 predictions which stated that if the trend held, we'd see 1.5C crossed in the early to mid 2030s, at a warming rate of around 0.2C / decade.

The best case scenario is that some of the 2023 warming is temporary and associated with Hunga Tonga, or the unique scenario of an El Nino following a triple La Nina, which hasn't happened in over a century. This would then create a temporary slowdown or even pause in the warming (the gradual warming trend being partially reversed for a few years as the excess water vapour is removed from the stratosphere).

The worst case is that the 2023 warming is related to a reduction in aerosol emissions, which would make it effectively like an instantaneous chunk of warming, that is now permanent. That is James Hansen's suggestion. He suggests that temperatures this year will be in the 1.6C-1.8C range, then the next La Nina will only mean a drop to 1.3-1.5C, which would mean that effectively we would be able to say that 1.5C passed in the mid 2020s, though of course we'd need several more years before a long-term average would show that.

This debate will run for a few years I think, until we see data from what should be the peak of the current El Nino's impact on temperatures (this year), and then what happens in 2025 and 2026. By that point it should be fairly obvious whether the anomalous warming in 2023 was a temporary thing or something more permanent.

[WYorksWeather]

Worth noting that Berkeley Earth are expecting to post their global temperature for 2023 on the 12th January, per their website.

[Methuselah]

It's the rate of change that's the problem:

 

Edited January 19 by Methuselah

[WYorksWeather]

5 hours ago, Methuselah said:

It's the rate of change that's the problem:

 

Yep, this is the key misconception. Of course the climate has varied enormously, but historically those changes fall into two categories. You have the very gradual changes due to orbital forcing, long-term variations in solar output, etc., but these operate on timescales of millennia, and in certain cases, like the impact of the long-term increase in solar output over the lifetime of the Sun, millions of years. During the Paleocene-Eocene epoch around 55 million years ago, there was an extraordinary peak in global temperature, to the point that there were no ice caps, and crocodiles roamed the North Pole. But life on Earth had millions of years to adjust to those conditions.

The second type of change is that caused by sudden catastrophic events, like the asteroid impact at the end of the Cretaceous period, which of course famously wiped out the dinosaurs, and less famously also wiped out almost every land species larger than a domestic cat. Of course that event was virtually instantaneous, whereas what we are doing to the climate happens over decades or centuries, but geologically speaking there's essentially no difference between an instantaneous change and one that takes 200-300 years. It just isn't enough time for significant adaptation to take place in the plant and animal kingdoms. As far as the Earth is considered, the Industrial Revolution may as well have started yesterday.

[Methuselah]

A prog about ice ages and such, it's just a shame that, according to the graph shown in the presentation, the MWP was clearly not warmer than today: 

 

[Methuselah]

Decoding the Weather Machine: a very good, and readily understandable PBS/Nova special:

 

[WYorksWeather]

 Methuselah Just saw this. Not sure whether you were being ironic or not?

Just to be clear (feel free to ignore if I've got the wrong end of the stick here) - the confusion over the MWP tends to be dependent on both location and time. Back in the 80s and 90s, estimates of global temperature in the MWP were generally higher relative to the late 19th century, and the amount of warming between the late 19th century and the then-present day was of course smaller than it is now.

More recently, studies have generally found that warming in the MWP was highly regional, and is marginal at best globally, possibly on the order of 0.1-0.2C over the late 19th century. Of course, there are still a very small number of locations that may have been warmer during the MWP than they are now - for the northern mid-latitudes as a whole the warming was around 0.5C on the late 19th century, and in some places it will have been significantly more than that. And of course global temperatures are now significantly higher than when the early IPCC studies were done in the 80s and early 90s.

On a global scale, the latest understanding is that current global temperatures are at least as warm, or possibly slightly warmer, than the peak of the Holocene Climatic Optimum around 6,500 years ago. The next comparator would be the Eemian period 125,000 years ago, but global temperatures are still significantly cooler than that. For example, in the Eemian, hippos were present in the Rhine and Thames, and tree cover was far more widespread in Scandinavia, Alaska and Northern Canada than it is today.

[raz.org.rain]

While on this subject, it would seem that localised SSTs around the British Isles and the North Atlantic are currently trending at below average anomalies. The North Atlantic factor may prove to be an interesting one as a cooler North Atlantic anomaly has proven to lead to persistent atmospheric conditions resulting in longer periods of intense heat across Europe. 2018 was a prime example of this in action. Perhaps more importantly, in theory is should translate to a considerably lower amount of rainfall across Northern Europe.

This is all just theoretical rambling at this point, but the lower SSTs may prove to be a crucial factor in the formation of any heat domes this summer, and I'd expect such anomalies to encroach well within our shores. 2003 has been suggested as a good analog for what to expect this year.

Edited February 4 by raz.org.rain

[WYorksWeather]

 raz.org.rain Localised SSTs around the British Isles are around average at the moment, and forecast to decrease to possibly slightly below average by day 15.

However, the same is emphatically not true for the wider North Atlantic, which remains above average.

Here it is in historical context.

The middle dashed line is the 1982-2011 mean. The North Atlantic is currently roughly a full degree C above that average, and 0.2C above the previous highest recorded temperature at this time of year. Doesn't sound like much of course, but that's an immense amount of excess energy, and is definitely fuelling some of the record mild records that have been seen here and across other parts of Europe.

[Methuselah]

 WYorksWeathe: I'm seldom ironic with AGW -- you'd be amazed at the number of times callers to radio stations cite the MWP as proof that AGW is all a scam.

[WYorksWeather]

 Methuselah I'm just hoping I don't see hippos in the Thames within my lifetime!

And yet, scenarios similar to current climate policies, like RCP4.5, would mean that if I live to my expected life expectancy, the climate of the Eemian would be reached before the end of the century. This would be around 3C above pre-industrial, meaning just under 2C over today globally. Probably around 3-4C over today for the UK given the land amplification.

[matty40s]

 

[matty40s]

 

[WYorksWeather]

January was also the warmest January on record, making it eight months on the spin. 1.66C over pre-industrial according to WMO using the ERA5 dataset (other datasets may very on exact figure by 0.1-0.2C).

World had warmest January on record

WMO.INT

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This is the eighth month in a row that is the warmest on record for the respective time of the year. Sea surface temperatures continue to be at record high.The average monthly surface air temperature was 1.66°C...

 

[matty40s]

 

[matty40s]

It just keeps getting worse....

 

[matty40s]

This is probably going to be worth having its own thread if things carry on.

The Mediterranean(Black Sea as well) has already seen a couple of extreme events this Winter, and is well above normal temps for the time of year. The Adriatic Sea(between Italy, and Balkans/Greece) is off the scale.

This could result in coral die off, and mass sea life death if it carries on to the Summer.

 

[matty40s]

We had a couple of small tornados today in the central belt of Italy....far too early in a normal year.

[WYorksWeather]

Looks like a pretty high chance that March will continue the record breaking run.

[LetItSnow!]

I feel like we'll tick down somewhat into 2025 and maybe even 2026 if we go into La Niña and lose some of this water vapour effects and maybe that'll give a false sense of semi-normality but it makes you wonder if we get another Super Niño between 2027 and 2040 how warm that could tip the scales.

[sundog]

Could a slower AMOC be helping to reduce the rate of sea ice loss in the Arctic.  Perhaps a reason why  the minimum extent record set in 2012 hasn't been beaten yet.

 

[Midlands Ice Age]

2 hours ago, sundog said:

Could a slower AMOC be helping to reduce the rate of sea ice loss in the Arctic.  Perhaps a reason why  the minimum extent record set in 2012 hasn't been beaten yet.

 

Sundog..

 I found this very interesting..  Thanks for the info.

I will probably also transfer this paper to the N H snow and ice thread, where I will display all the latest extent and area charts for the relevant Arctic regions. It is incredible how they fit the output scenario that the paper predicted.      

As you will know If you have been reading the above thread, I have been reporting that the sea ice  in the Arctic has not been following the trend of the climate models over the last few years (3 - 5  possibly) not very well at all), and I have reported on great detail on this and have at times had discussions with @WestYorksWeather on why this may be occuring.

I had picked up the increased trend for the ice increases in exactly the areas specified (Barents, Kara in the western Arctic) and I have also picked up the recent increases in the Eastern Arctic waters (Pacific - Bering and the SOO) which this paper also proposes will show an increased tendency to grow ice under their modelled output.

I have 3 real points to make -

1) the slow down effect of the AMOC is real. It has been  measured in 3 or 4 different places now, across the Atlantic. It is the main driver for heat  transfer across the equator from south to north. It has not been investigated (or even included)  by the climate models until perhaps very recently (The Rel 6 IPCC paper does not show that it has any major impacts from it, eg). Certainly 5 years ago  it was not counted as a real driver of climate change - as it was assumed that it had no net world wide climate temperature change. It is now being suggested that it may well do by virtue of the 'albedo' and the other impacts discussed above on the atmospheric temperature profile/change resulting from the changes in the ocean currents. 

It is also interesting to note that they modelled the opposite effect in the southern hemisphere.... SO the CC  overall 'net' assumption impact on temperature may be valid, but it would involve much detail weather characteristic event differences being forecast for both hemispheres.

 

2) This is just one model - there are around a dozen out there. They say that they will extend their work into others. I will be interested to see if they show the same trends.

3) I have been thinking (In common with many others) about the changes of weather being experienced  most notably in the western Atlantic. This 'different' weather is not exclusive to Europe though. Odd weather is also being reported in North America (resulting in a 10 year low in the Great Lakes ice), and also in the Pacific where sea ice levels are at a 10 year high for this time in the season..  @Mattyh and @KirkaldyWeather have also been 'hard at it'

Also in Barents and the Greenland Oceans (+even Baltic)  where very unusual sea ice late increases in trend  are even now still occuring,-  despite the melt season being over 2 weeks old now.  

My feeling on all this is that the Arctic Polar Vortex has been very weak this year at the tropospheric level, and where  it has been mainly dominated by weak 'flat' areas of high pressure. (when compared to a raging PV.)

This HP has in turn prevented deep low pressure areas from entering the polar regions from the Atlantic, and also the lack of real high pressure has prevented a strong enough reversion of the normal westerly flow across the sub Arctic regions (widespread easterlies).

This combined event has for us (for our atlantic areas - not looked at other regions) led to the southerly tracking jet stream for most of the winter (since last July actually), being forced by the weak polar vortex over Canada pumping low pressure zones across the Atlantic , and has also allowed  the 'Iberian heights' to gain control for some spells, whenever the jet stream weakened at all. 

I had intended giving my own interpretation of our current climate, and this paper seems to give my thoughts at least some background for being correct.

I guess the major question is - what is it that can break us out of the current relentless westerly low pressures, which always seem to stall over or just to the west of us?

My guess is that it will take a change of some sort in the Arctic to either push these depression through, and then we can get  a 'reset'; or perhaps weaken sufficiently to enable the southern heights to take over.  Perhaps the 'final warming' event or we just drift into a summer pattern, with high pressure nosing in from the south. 

Over to the NH snow and ice forum for me.   !!!

MIA

Edited March 28 by Midlands Ice Age

[raz.org.rain]

 sundog whilst on the subject of the AMOC, it's worth mentioning this article;

How melting Arctic ice leads to European drought and heatwaves

ARSTECHNICA.COM

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Fresh, cold water from Greenland ice melting upsets North Atlantic currents.

I feel that we're only just beginning to understand how changes in ocean currents actually affect the climate of the midlatitudes. And then of course we've got the hypothetical implications of less excess atmospheric heat being circulated into the deep oceans by a slower AMOC, so it stagnates in the atmosphere instead. It's a curious subject and I feel it gets poorly communicated.

[sundog]

 Midlands Ice Age your welcome . Fair play to you if your thoughts are similar to that paper. Will be interesting to see what happens going forward.........

[Pennine Ten Foot Drifts]

5 hours ago, Midlands Ice Age said:

I guess the major question is - what is it that can break us out of the current relentless westerly low pressures, which always seem to stall over or just to the west of us?

My guess is that it will take a change of some sort in the Arctic to either push these depression through, and then we can get  a 'reset'; or perhaps weaken sufficiently to enable the southern heights to take over.  Perhaps the 'final warming' event or we just drift into a summer pattern, with high pressure nosing in from the south. 

MIA - this is the bit that I'm very interested in (and somewhat concerned by). My basic understanding is that two particular elements are helping drive our, (as in the UK), recent (i.e. the last 18-24 months) dominant weather (procession of low pressures, very limited settled dry weather):

1. The reduction in the temperature difference between mid-latitudes and the Arctic weakening the northern polar jet and causing it (combined with other factors you've mentioned) to persist on a more southerly track.

2. Generally warmer air, therefore holding more moisture, leading to heavier rainfall associated with the procession of depressions.

If this is generally correct does that not mean that this type of pattern is going to persist for potentially many years (at least in human terms i.e potentially 5-10 years) until the next 'level' of climate change kicks in and we move to the next phase? (however that manifests itself).