chubbs

The article below provides a good summary of how recent energy trends are impacting IPCC emission scenarios. While I am even more pessimistic about the science of climate than I was a decade ago, I have become much more optimistic about non-fossil energy technology and natural gas vs coal. Limited policy and luck has improved the "worst-case" considerably vs CMIP5 IPCC scenarios. Unfortunately though, we haven't made any progress on the "best" case due to inaction/denial. Recent experience shows that improved climate policy and support for renewable energy technology could have enormous long-term pay-back. https://thebreakthrough.org/issues/energy/3c-world

Very strong warming the past 5-6 years. The warm departure from the trend-line has stayed more prominent than the cool departure during the hiatus.

Off the charts surface melting so far this summer in Antarctica aided by the September SSW with temperatures above normal since late September. http://climato.be/cms/index.php?climato=the-2020-melt-season-over-antarctica-as-simulated-by-marv3-10

Strong ocean warming since the end of the hiatus. The 2016 super nino spike was completely erased by the following la nina. It's the non-super nino periods that have been killing us. Most recently we have warmed in the past year even though 3.4 temps have cooled.

GISS vs CMIP5 forcing (source for forcing # below, volcanoes*0.25 reflecting observed response to short duration activity). Observed TCR is roughly 1.8 inline with model estimates. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD028481

GISS - the current spike has fully corrected the hiatus, but the 11-year mean hasn't turned up much --- yet. http://www.columbia.edu/~mhs119/Temperature/

PV = photovoltaic i.e. solar

Here is solar in previous IEA outlooks - 2035 in the base case is undoubtedly conservative.

Saw this on twitter from the International Energy Agency's recently issued 2019 World Energy Outlook. Base case on left, sustainable development, broadly consistent with Paris targets, on right. Solar forecast to be #1 in global power generation by 2035 in base case. That date is moved forward to 2028 for "sustainable development". This isn't rocket science.

From ZHausfather's twitter. Every possible trend to present, CMIP5 vs obs. Warming has picked-up in the past decade or so and is now faster than CMIP5 models.

HadSST vs CMIP5 RCP6 SST prediction. 2019 is through Sept for HADSST3 and not available for HADSST4. Overall CMIP5 is performing well. The post-hiatus spike has taken SST from below to above the model prediction.

Here is the RSS TLT maps for Sept and Aug. I don't see any evidence that the SHemi strat warming had much impact. The September warmth occurred in pockets across the globe (including E US). Probably just a fluky satellite month.

A strong enough carbon tax would quickly put us on a much better trajectory, been a no-brainer for decades. Much better to tax carbon than income.

Think this will go down to the wire. The Pac-side pack has been deteriorating in a favorable pattern.

Looking more and more like a 2 horse race

From Amy Butler's twitter. Unusual coupling of the stratosphere and troposphere this summer. Models at times too eager to end pattern.

4 days later forecasts are variable but most keep it going for quite some time - probably helping by preventing a classic dipole

Recent summer warming in the Yukon exceeds the Holocene climatic maximum despite reduced summer insolation vs early Holocene. https://t.co/gCPWogUB5N

IPO phase could bring September ice-free date forward. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL081393

Antarctic sea ice has large natural variability. Here are a couple of speculations: 1) I don't recall the details but one paper flagged the the large nino in 2015/16. For sea ice the timing does line-up, 2) The antarctic ozone hole is slowly recovering this would tend to weaken winds and produce warming, both of which will reduce sea ice extent 3) Antarctica warming lags because of the deep ocean nearby which is slow to warm. as time proceeds though Antarctica will catch-up. Per the chart below, the south pole has also warmed in the past decade in a way that doesn't match enso, so it is likely more than just enso.

Rapidly receding Arctic Canada glaciers revealing landscapes continuously ice-covered for more than 40,000 years Here we show that pre-Holocene radiocarbon dates on plants collected at the margins of 30 ice caps in Arctic Canada suggest those locations were continuously ice covered for > 40 kyr, but are now ice-free. We use in situ 14C inventories in rocks from nine locations to explore the possibility of brief exposure during the warm early Holocene. Modeling the evolution of in situ 14C confirms that Holocene exposure is unlikely at all but one of the sites. Viewed in the context of temperature records from Greenland ice cores, our results suggest that summer warmth of the past century exceeds now any century in ~115,000 years. https://www.nature.com/articles/s41467-019-08307-w

November Antarctic sea ice. Blutarsky.

Below is the best discussion of the available data for the past 1500 years. The current warming is unprecedented. Year-to-year variation in sea ice is expected. We get the sea ice is recovering story periodically in this forum: 2008/9, 2013/14, etc. Sea ice is not crashing and its not recovering, just a steady long-term decline with large year-to-year variability. https://www.nature.com/articles/nature10581

Below is the daily sea ice anomaly and a one-year running average. Autumn, winter and spring have been leading the way down recently.

Go back an re-read what I posted earlier. 1) Sea ice is lower now than anytime in past 2000 years. Sure sea ice was lower in the early Holocene >5000 years ago. Summer sun in the northern hemisphere was stronger then. Summer sun is much weaker now; but, sea ice is decreasing rapidly. Why? CO2 of course, different type of forcing same result. All consistent with consensus science. 2) Per your chart, sea ice in the northern Barents Sea has been stable throughout most of the Holocene. Satellite data shows sea ice is crashing now. Why the difference? The recent crash doesn't appear on your chart; because, the method, used to study past climates, doesn't have the time resolution to pick-up the crash. Nothing wrong with the chart; just bad and misleading analysis by Electroverse.