CC3 -- Why I believe that a third option is needed for climate change

Oneiric 3 wrote: »

Interesting.. in more ways that one:

https://www.youtube.com/watch?v=6Yz8nZbZPE8

I've noticed that in the last few months, there seems to be a slight steer away from the narrative of excess and dangerous warming towards one that that is now trying to fill us with fear about a potentially dangerous cooling... if we don't repent of our sins.

The plot thickens.

Oneiric 3 wrote: »

Interesting.. in more ways that one:

https://www.youtube.com/watch?v=6Yz8nZbZPE8

I've noticed that in the last few months, there seems to be a slight steer away from the narrative of excess and dangerous warming towards one that that is now trying to fill us with fear about a potentially dangerous cooling... if we don't repent of our sins.

The plot thickens.

Oneiric 3 wrote: »

I wouldn't have posted a link to it if I didn't.

Akrasia wrote: »

So where did you get the narrative that we have switched from global warming to ‘a potentially dangerous cooling’

That was nowhere in the video you posted

Akrasia wrote: »

I did watch the video
The AMOC transports heat. If the AMOC shuts down in 3 hundred years time, it won't cool the planet, it could cause the north atlantic to cool down, but that heat in the tropics won't simply disappear, it could lead to catestrophic warming in other parts of the world

People who are concerned with Climate Change are not just worried that it will get hotter, we are concerned that it destabalises existing climate systems causing mass disruption to ecology, economies and agriculture

Climate change, or Global warming, whatever you want to call it, risks destablaising climate systems all around the world, this is why it needs to be taken extremely seriously because if you think the social and economic disruption caused by Coronavirus is bad, it would be absolutely nothing compared to what we will see if we allow the planet to warm by 2c+ over preindustrial levels.

I don't know why antarctica is projected to be so cold this year. Its the middle of winter there, and weather is weather It could be 20c warmer than average the week after
You need to look at climate, not weather when talking about climate change

Akrasia wrote: »

I don't know why antarctica is projected to be so cold this year. Its the middle of winter there, and weather is weather It could be 20c warmer than average the week after ou need to look at climate, not weather when talking about climate change

M.T. Cranium wrote: »

I don't think that statement about hurricanes recently is particularly supported by actual evidence. Some of the most damaging hurricane impacts are well back in the past. I could mention the Galveston hurricane of 1900 and two intense hurricanes that hit Florida in the 1920s as evidence that if anything the actual trend is slightly in the opposite direction, but personally I find it steady-state although cyclical in nature.

The 1980s were generally a decade of weak Atlantic hurricane development especially before 1988. So relative to that weak decade the recent past has picked up in intensity. But the 1940s and 1950s were probably just as intense as the recent decades.

If I had to name the single most prolific hurricane season, 1780 had five very damaging hurricanes in the Caribbean region. Of course we don't know what the total seasonal count was that far back with no observation of many parts of the hurricane theatre.

Harvey drenched Houston with an enormous rainfall but here again, similar things have happened in the past, they sometimes happened more over less populated areas but I don't think we can really take impacts on cities as a primary guide to inter-decadal comparisons, if something similar happened in a less populated area, it still shows that the phenomenon is recurring.

Similar analysis could be applied to typhoons and Australian, Indian Ocean and South Pacific theatres as well as the south coast of Mexico.

There was a much stronger tropical cyclone in 1970 in the Bay of Bengal than this recent one that attracted a lot of attention, IIRC the death toll from that was upwards of 200,000 people in Bangladesh and India.

I realize the theory is that slightly warmer ocean temperatures will intensify storms, but the ebb and flow of anomalies and the feedback loops where powerful storms begin to cool local areas of the sea surface come into play.

People might also want to offer up Sandy (late October 2012) as a singularity but in my research into 19th century events, I found two similar landfalling hurricanes in 1849 (Oct 6-7) and 1861 (Nov 1-3) that brought similar amounts of rain to many parts of the northeast U.S. and into the Great Lakes region. The details are different, this is what makes comparing long-term severe weather frequencies difficult, there is always going to be some detail that is unprecedented, that is the nature of severe weather events.

Theoretical understanding of the thermodynamic controls on tropical cyclone (TC) wind intensity, as well as numerical simulations, implies a positive trend in TC intensity in a warming world. The global instrumental record of TC intensity, however, is known to be heterogeneous in both space and time and is generally unsuitable for global trend analysis. To address this, a homogenized data record based on satellite data was previously created for the period 1982–2009. The 28-y homogenized record exhibited increasing global TC intensity trends, but they were not statistically significant at the 95% confidence level. Based on observed trends in the thermodynamic mean state of the tropical environment during this period, however, it was argued that the 28-y period was likely close to, but shorter than, the time required for a statistically significant positive global TC intensity trend to appear. Here the homogenized global TC intensity record is extended to the 39-y period 1979–2017, and statistically significant (at the 95% confidence level) increases are identified. Increases and trends are found in the exceedance probability and proportion of major (Saffir−Simpson categories 3 to 5) TC intensities, which is consistent with expectations based on theoretical understanding and trends identified in numerical simulations in warming scenarios. Major TCs pose, by far, the greatest threat to lives and property. Between the early and latter halves of the time period, the major TC exceedance probability increases by about 8% per decade, with a 95% CI of 2 to 15% per decade.
https://www.pnas.org/content/117/22/11975

Akrasia wrote: »

The most recent studies have found a satistically significant increasing trend in the number of major storms over the past 4 decades, now, you might not think 4 decades is long enough to come to a conclusion, but we're stuck with the data that we have, previous records are too heterogenious to properly compare using observed records.

If you look at cyclone activity globally rather than focusing on individual regions where there may be more natural cycles in play, you can smooth out these cycles to get a better overall view on how climate change is affecting global tropical cyclone activity.

You can hypothesise that in the 1700s there were more powerful storms but there will always be once in a century storms, often even several of those storms in the same century due to the way probabilty works. The problem is that climate change models predict that there may be fewer hurricanes overall, but that there will be more major hurricanes, and that those hurricanes will cause increased flooding due to warmer oceans feeding them and warmer air allowing them to hold more moisture

We have model based predictions, and we can compare those predictions to the actual outcomes that we are observing, and the evidence is mounting that there is a statistically significant rise in the number of severe storms globally


I've posted a study below, the conclusions of the researchers are that there was a recent decadal increase of 8% in the number of major storms globally


Every year that passes will give us more data to add to the statistical significance of these trends but we cannot wait until there is absolutely no uncertainty because 1. that will never happen, and 2, by that time it will be much too late to delay or reverse the worst impacts of climate change

Gaoth Laidir wrote: »

But in a warming world, where global ocean heat content is supposed to be increasing, why are we seeing no statistically significant increase in global ACE? Regional variability aside, the overall global trend should be increasing. A higher number of stronger, more powerful and longer-lasting storms should show a much more significant trend than just 0.4 (about 0.05%) per annum, given that ACE is related to max wind squared. Where's all that extra energy gone?

http://tropical.atmos.colostate.edu/Realtime/index.php?arch&loc=global

Gaoth Laidir wrote: »

The theory stated in the article you posted relates storm intensity to a warming world. So what do they mean by intensity? Have the goalposts now shifted and intensity no longer refers to max winds and minimum pressure and storm longevity (something you're quick to quote when these numbers become interesting, e.g. in the case of Patricia)? It's now moved on to not so much how hard she blows but rather where she blows? The real estate of the landfall point is now a factor? Had Sandy not made landfall where it did we would not be talking about it. It briefly reached Cat 3 earlier on and was barely a Cat 1 when it did hit, so all the damage was done by the storm surge. As MT has shown, this is not the first time this area has been hit by such storms, but when you put 100 million people (more importantly, Americans) in the way then everything stops and the media frenzy starts.

The actual number of Atlantic Cat 3+ storms in the past 40 years shows a meagre rise of around 0.5 storms per decade, or an increase of just +1.5 storm days per decade. This is in the most sensitive basin in the world. In the NW Pacific the trend is even less pronounced (+0.2 storms and +0.8 days per decade), despite a rise of around 0.7 °C in 0-100 m water heat content there. Yet we are to believe that there are clear and unequivocal signs of destructive increases in this basin, home to hundreds of millions of vulnerable populations, but the data don't reflect this.



Storm size is one thing, but even that study said that it couldn't find a trend in a 28-year dataset and had to extend out to 39 years (cherrypicking, as you say?) to find one. This is exactly of the same magnitude of the natural variability of the system (AMO, etc.), to which the Atlantic storm activity and that of other basins are primarily linked.

ACE is one of the prime measurements used by the NHC and other bodies in classifying individual storms and seasons. Just because it is not showing any appreciable trend is not a reason to discard it. If indivicual storms really are becoming stronger then ACE should be showing it. Size doesn't matter.

Danno wrote: »

Thank you for stating that a 28-year dataset is not enough. And, also - thank you for stating the highlighted piece above.

M.T. Cranium wrote: »

I have been adding the NYC monthly data to my Toronto data study, the more extreme values are already posted in the thread. There seems to be a good correlation in monthly rankings although there's a small subset of months where NYC runs considerably warmer (relative to normal) as the storm track takes a position between the two locations.

But probably 80% of the months are within a few ranks of each other in the two data sets and quite a few of the top fives are the same, if maybe in scrambled order.

What jumped out at me was the fact that Dec 2015 was even more anomalously warm for NYC than for the CET or Toronto. It is the warmest December at all three locations and by a wide margin, but in the case of NYC it was almost five C deg warmer than the previous max. This points to a process that we don't fully understand yet, whether human activity is a large factor or not, a sudden and not very prolonged burst of extreme warmth that is not obviously related to the solar cycle. In North America two other such bursts of extreme heat were noted in September 1881 and July 1936 but neither of these showed up in Europe.

The weather patterns in Dec 2015 suggest that the source of the anomalous warmth was the Gulf of Mexico as there was no evidence of Pacific warmth intruding in either Nov or Dec 2015 (for example PHX was below normal both of those months, but Houston TX had extreme warmth early in Dec 2015). This extreme warming event cannot be easily explained as an AGW phenomenon as it has not happened on the same scale again. It came towards the end of a rather weak solar cycle peak, so I don't think we can say a hyperactive Sun had much to do with it either.

For whatever reason the Gulf of Mexico shed a lot of anomalous heat in Nov-Dec 2015. This sparked a general release of subtropical heat all the way from the south central U.S. to Britain and Ireland in the path of the Gulf stream. The month was 7 to 8 C deg above normal in many places, including Norfolk VA where it was 28 C on Christmas Day.

If we have future events like this on a more regular basis, it is going to send extreme warmth into higher latitudes because each time it happens there will be a tendency for storm tracks to shift further north.

I think in my own subconscious, this event (which I noticed at the time in the sort of chaos of my day to day weather forum activity which is probably too much for real concentration on research, with the forecasts and contests that I manage) is probably part of the foundation for my thinking that prolonged natural warming seems inevitable and if this has been produced entirely or largely by human activity then I can't really see how anything we do now would reverse the tendency. The best we can hope to achieve is a slowdown of the greenhouse gas increase.

I don't actually think this Dec 2015 is a manifestation of human activity. I think maybe there is enough of a long lag in the inter-glacial peak of warming that we are entering that peak warmth period now, even if Milankovitch drivers are backing off slightly -- every other natural cycle has a lag built in, so it would not surprise me if responses to Milankovitch cycles have a lag -- the conservative nature of ocean temperature is the main reason for this.

Looking through the three data sets to try to identify perhaps one other similar event. Summer 1911 seems to have some similar correlations. It was also very warm in the same large area in the summer of 1955.

The amount by which previous records were broken in Dec 2015 is, however, unprecedented in all data sets. Having lived through a new record warm December back in 1982, that one only edged out the previous record by a small margin (and failed to do so at NYC with no warm signal in Europe at all); since then several Decembers have been warmer. In general, December and February seem to be the most warmed of all the months in the North American data. I suppose this is part of the phenomenon of shorter winter seasons, not as impactful on January (yet).

Akrasia wrote: »

ooookaaay

I know what the summer solstice is, it happens every year, so it doesn't explain why this particular year is seeing such unprecedented temperatures with places in Siberia reaching 38c

Birdnuts wrote: »

The accurate recording of temps in the likes of Siberia goes back barely 100 years, so your assumptions on the matter count for little:rolleyes:

Oneiric 3 wrote: »

That video I posted a while back explained how the decrease in pollutants & aerosols has caused the Arctic region to warm and sea ice to decrease even more than it was already doing since the 'lockdown' began.