chubbs

Re the Mann vs Hanson discussion above, chart below (updated recently through 2024) shows how man-made forcing has increased in past decade or so leading to an increase in human induced warming. Link below has 2023 paper with details. Chart is for a 2024 update to the paper that is being prepared. https://essd.copernicus.org/articles/15/2295/2023/

Scientists have been looking at preindustrial climate impacts for a while. Burning, land-use change, and agriculture released GHG and aerosols and changed albedo. Not sure what the latest science says, but post-industrial impacts are much larger. Below is a 2021 write-up I googled up. https://www.globalpolicyjournal.com/blog/24/02/2021/ruddiman-hypothesis-debated-theory-progresses-along-interdisciplinary-lines

You make good points but I have a few bones to pick. I don't think silver bullet is the right word. Its never just one thing in weather/climate. Aerosols help explain the acceleration in temperatures in the past 15 years, but other factors had to align to produce a spike in 2023. I would not put much of the blame on science either. They have been ringing the climate alarm bell for a while and have long recognized aerosols as a key uncertainty. The lack of concern/urgency has caused aerosol science to be underfunded. Agree that climate's complexity make it difficult to deal with; but, also think our own human nature is important. We have certain attributes that get in the way of facing climate and certain other problems: short-term focus, self interest, greed, resistance to change, confirmation bias, denial, etc.

An interesting question. Stepping back don't think that Team Mann or Hanson are that far apart. They are still on Team Climate Science. Saw a chart recently, but can't recall where, so can't post, that showed that Hanson's yellow cone overlay the CMIP6 projections, i.e., acceleration is expected due to an increase in forcing. However, think that the Mann/IPCC team is losing unfortunately. As I will explain below. Hanson is right that aerosols are key for untangling our recent climate history. The chart below taken from a recent Climate Brink blog (link below) illustrates this. Aerosols have been masking the effects of CO2 and other GHG. There have been 3 broad GHG and aerosol forcing regimes (dates rough): 1) Pre-1970 where aerosols increased at roughly the same pace as GHG and masked almost all GHG warming, 2) 1970-2014 where aerosol emissions stabilized due to increasing clean air regulation allowing a steady rise in net man-made forcing (GHG+aerosols) as GHG continued to increase and 3) The last decade or so with decreasing aerosols which unmasked GHG in the atmosphere causing the rate of forcing to increase. We are now getting the effect of new GHG as they are emitted, plus the old GHG that had been masked. Temperatures have tracked forcing (warming rates and dates rough): 1) Before 1970 - stable, 2) 1970-2014: steady 0.18 increase, 3) Post 2014: 0.25+ per decade. Of course the regimes didn't change as suddenly and other factors have played a role as described in the Hanson paper: sun, volcanoes, shipping rules, etc. Hanson is also right that an increasing aerosol effect implies higher climate sensitivity when using recently observed temperatures to estimate climate sensitivity. However, there are other ways of estimating climate sensitivity, i.e, Hanson is underestimating the uncertainty in ECS. I don't see enough evidence that climate sensitivity is at the high end. What has happened though is the low end has been lost, ECS is not under 3, recent science and the acceleration in temperatures make that clear. My personal range is 3-4C per CO2 doubling. More important than climate sensitivity, it is clear that policy and emissions aren't following any IPCC scenario; and, with the election of Trump aren't likely to in the near future. We've made some progress on CO2 as the economic position of coal and renewables has changed, taking CO2 off the worst case path. However non-CO2 pollutants, aerosols (decreasing too fast), methane and N2O, are all on worst case paths and total net forcing is increasing at about the same rate as RCP85. The only good news is that the rapid increase in forcing is temporary, there are only so many aerosols to be eliminated. So where does that leave us? In a rapidly changing climate unfortunately. The masking effect of aerosols has fooled us and helped put us on a path that maximizes climate shock. We masked GHG warming for a long time while we slowly added GHG to the atmosphere. Now we are unmasking at a relatively rapid rate, without serious emission control. A dangerous policy combination. We are headed toward our climate future at an accelerating rate, while at the same time not preparing for the consequences. Buckle up. https://www.theclimatebrink.com/p/exploring-the-drivers-of-modern-global

Ceres net radiation updated through last November. Net radiation continues to bottom out, consistent with transition to la nina, as nino warmth is radiated to space. Have to go back to 2009/10 for nino-related dip as large as current. However, this cycle is bottoming out at elevated level similar to recent dips, so would expect rapid warming to continue.

Our local Chester County weather is changing exactly as expected with GHG warming, just like the rest of the region. Chester County has warmed 3-4F since Coop data collection started in the 1890s. Nights and winters are warming the fastest. Rainfall is increasing, particularly heavy rains. Our snowfall is increasingly concentrated in a few heavy storms/winters. Clear as day if you analyze the data properly. We beat the Chesco temperature data to death recently. Despite all the complaints about alarmism, NOAA was spot on.

The adverse pattern started to impact sea ice volume near the end of January (updated monthly). With the adverse weather, expect continuing negative volume impact in the first half of February. Keeping this year #2 behind 2017, another post strong nino year.

Yes, up to +20C surface anomalies today, but forecast to start dropping over next couple of days.

Didn't get any better on 2-6.

Here's a link. If you dig on website you can find all the details. This is usually the first estimate using GHCN to come out each month. https://moyhu.blogspot.com/

Good to see you post again. Congrats on the call you made during the hiatus for 0.2C/decade warming. May end up low, but at least you were in the right neighborhood, unlike the rest of us.

January observed temperature anomalies relative to a 1950-80 base. No temperature bias adjustment because the global average isn't impacted significantly. A record in this series by 0.04C. https://moyhu.blogspot.com/

For the winter-to-date (12/1 to 2/3) the lower 48 is close to normal.

Big storm/warm air surge on the Atlantic side this week have sent arctic sea ice into record territory.

Here's a map of Jan temperature anomalies through Jan 25 (JRA reanalysis). Very cold in SE quadrant of US, but there are several very warm areas scattered around the planet to balance. For northern hemisphere land, Eurasia and Canada more than offset a cold US. The JRA record for Jan is 0.64 set last year, currently 0.71 and likely to be broken this year. Very unusual to break a winter monthly average temperature record in a La Nina, not sure it has ever happened before.