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Unforced variations: May 2019

Filed under: — group @ 2 May 2019

This month’s open thread about climate science topics. For discussions about solutions and policy, please use the Forced Responses open thread.

161 Responses to “Unforced variations: May 2019”

  1. 151
    MA Rodger says:

    There is a whole babble of stuff on CH4 feedbacks in recent posts, linkage of which has been made to the Crowther comment (see upthread @60) which was specifically permafrost, today and spanning CO2 as well as CH4. Delving into the cited references, I don’t see any support for a significant CH4 component of the Crowther statement, but rather the opposite – eg:-

    Dean et al (2018) ‘Methane Feedbacks to the Global Climate System in a Warmer World.’
    “We determine that wetlands will form the majority of the CH4 climate feedback up to 2100. Beyond this timescale, CH4 emissions from marine and freshwater systems and permafrost environments could become more important. Significant CH4 emissions to the atmosphere from the dissociation of methane hydrates are not expected in the near future. Our key findings highlight the importance of quantifying whether CH4 consumption can counterbalance CH4 production under future climate scenarios.

    One reference worthy of highlighting is to the NOAA Annual Greenhouse Gas Index page as it has now updated to include 2018 data. The NOAA AGGI annual increases (along with earlier annual climate forcing increases) graphed here (usually two clicks to ‘download your attachment’) has been duly updated to incorporate/show the 2018 increase.

  2. 152
    mike says:

    methane and carbon release from warmed Arctic region?

    https://www.youtube.com/watch?time_continue=82&v=awNnw_e9KL8

    My interest/concern is really quite a bit larger than ghg releases from thawing permafrost. What I am trying to understand or scale is the amount of new “natural” ghg emissions that come from all the planetary features that have changed/are changing as heat increases. This research article covers a lot of the known unknowns on that. The changes in the carbon cycle that relate to global warming are a feedback and may not be reversible. It is interesting to note that Nisbet et al say “Methane’s increase since 2007 was not expected in future greenhouse gas scenarios compliant with the targets of the Paris Agreement, and if the increase continues at the same rates it may
    become very difficult to meet the Paris goals. There is now urgent need to reduce methane emissions, especially from the fossil fuel industry”

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GB006009

    I will note that the suggested focus on reducing emissions from the fossil fuel industry is mentioned because it is a source within our control. Farming and ruminant/cattle industry could also change to reduce emissions, but that is not mentioned as prominently as the fossil fuel emission source. There is a lot of interesting discussion about flooding, non-frozen wetlands as contributors to spikes in methane.

    I think this should all turn out to be fine. Nisbet et al sound convinced and appear to be getting a little wound up. I don’t think we need to get wound up about this. There is too much uncertainty regarding the methane buildup in the atmosphere. If you see a methane molecule, capture it, check out its carbon isotope and report back.

    Cheers,

    Mike

  3. 153
    Barry Finch says:

    133, 135 patrick027, 137 MA Rodger, 139 Mr. Know It All: Thanks. Don’t know when I’ll get to study all that but looks interesting. Here’s what it’s all about. I decided early 2018 though that the answer is that it’s sub negligible owing to speed of light a bit on the fast side so only might be a minor academic interest and not a revelation for RSS/UAH TLT analysis. I’d like to get the quantity and verify that certain though, also do the fun learning. It’s (likely) possibility (4) below.

    From: support@remss.com Sent: Monday, November 13, 2017 12:58 To: ‘BarryFinch’
    Subject: RE: STAR MSU onboard calibration procedure mismatches a solid-housed thermometer placed in the atmosphere
    Hello Barry, Let me look into this and get back to you.
    Sincerely,
    Michael Densberger
    Remote Sensing Systems
    707-545-2904 ext. 11
    From: BarryFinch Sent: Saturday, November 11, 2017 4:00 PM To: support@remss.com
    Subject: STAR MSU onboard calibration procedure mismatches a solid-housed thermometer placed in the atmosphere
    If I’m understanding the STAR microwave sounding unit (MSU/AMSU) onboard calibration procedure correctly, then it measures a different physical aspect of Earth’s atmosphere than is measured by a thermometer (either liquid-expansion or platinum-resistance) and it measures a lesser physical aspect. The underlying reason for the difference is that there is no long-wave radiation (LWR) inside a solid such as a platinum-resistance thermometer. I’ve never heard a climate scientist mention this.
    If the lower tropospheric (for example) atmosphere warms then there is an anomaly in these forms of energy:
    – molecular kinetic energy (molecular translational energy, heat),
    – LWR energy,
    – molecular vibrational energy of the GHGs (primarily H2O in the gaseous form).
    The warm target in a MSU/AMSU is a solid blackbody whose temperature is measured by platinum resistance thermometers embedded in it. The microwave flux density from it is used to scale microwave flux density (thermal emission) from molecules (primarily oxygen) in the atmosphere. The issue I see is that this onboard calibration procedure causes the instrument to scale such that it measures only molecular kinetic energy (molecular translational energy, heat) in the atmosphere and excludes LWR energy and molecular vibrational energy of the GHGs in the atmosphere. This means that differentiation over time of this proxy measures only heat anomaly.
    A liquid-expansion or platinum-resistance thermometer placed in the atmosphere at elevation 2m (for example) above ocean or land surface measures:
    – molecular kinetic energy (molecular translational energy, heat) plus
    – LWR energy plus
    – molecular vibrational energy of the GHGs (primarily H2O in the gaseous form)
    because LWR energy and molecular vibrational energy of the GHGs are transmuted to molecular kinetic energy (molecular translational energy, heat) upon impacting upon the molecules of the solid and I understand that there is no transverse electromagnetic radiation inside a solid. Placement of the thermometer inside an enclosure does not exclude the LWR energy and molecular vibrational energy of the GHGs due to GHG molecule collisions.
    Thus, differentiation over time of the liquid-expansion or platinum-resistance thermometer proxies for temperature measures the sum of all three anomalies but differentiation over time of the microwave flux density (thermal emission) from molecules (primarily oxygen) in the atmosphere at the example elevation of 2m measures only the molecular kinetic energy (molecular translational energy, heat) anomaly with the STAR microwave sounding unit (MSU/AMSU) onboard calibration procedure as described. In order for the MSU/AMSU to measure the same physical aspect as a liquid-expansion or platinum-resistance thermometer it would be necessary to calibrate with the warm target being atmospheric gases in close proximity to a solid whose temperature is measured by platinum-resistance thermometers, or a compensating adjustment could be made during analysis such as RSS and UAH based upon the ratio of LWR energy + molecular vibrational energy of GHGs to molecular kinetic energy in the atmosphere.
    Please inform whether:
    1) I’m misunderstanding the physics, or
    2) I’m not including another aspect of STAR microwave sounding unit (MSU/AMSU) onboard calibration procedure that deals with this issue, or
    3) A compensating adjustment for this is made during analysis such as RSS and UAH based upon the ratio of LWR + molecular vibrational energy of GHGs energy to molecular kinetic energy in the atmosphere, or
    4) The ratio of LWR + molecular vibrational energy of GHGs energy to molecular kinetic energy in the atmosphere is so negligible (far less than uncertainties) that no compensating adjustment for it is required for analysis such as RSS and UAH.
    Thanks

  4. 154
    mike says:

    At Al:
    May 19 – 25, 2019 414.74 ppm
    May 19 – 25, 2018 411.44 ppm

    Has the rate of CO2 increase in the atmosphere slowed or stopped from what you can see?

    Ray at 130: You and I are in total agreement that our government has been hijacked by special interests. I have also stopped engaging in marches/protests, primarily because the Trump success in 2016 just changed the game for me.

    Cheers

    Mike

  5. 155
    Jim Ryan says:

    Has this Soon paper from 2015 been rebutted?
    ‘Re-evaluating the role of solar variability on Northern Hemisphere temperature trends since the 19th century’. One of the authors Roman Connolly was on Delingpole podcast and came across as earnest . I’m a proponent of AGW but paper is too technical for me. Delingpole, who is scientifically illiterate, was salivating. Paper hasn’t received many citations which perhaps hints at lack of quality?

  6. 156
    Killian says:

    Re #146 mike said time will tell who is right…

    No, it won’t. We already know. MAR is wrong. He always is because his response is always the same: There’s not much to see here. Nope, not happening all that fast. Don’t be skyrockety.

    And, yet, we have seen nothing but faster than expected wrt climate, ecosystem collapse, pollution, growth. MAR is and always will be wrong until MAR learns his ideology and belief are no match for objective reality.

    MAR is, in my view of denialists, the last level: It ain’t so bad, let’s not move too fast or assume too much. It’s a sort of unintentional denial due to the cognitive biases.

    I have thought since 2007 when Walter, et al., published on thermokarst lakes that those who are sanguine about CH4 from Arctic sources will one day need to be sanguine about societal collapse, ecosystem collapse and mass extinction if they prove the more influential policy-wise.

  7. 157
    MA Rodger says:

    Jim Ryan @155,
    You ask if Soon et al (2015) ‘Re-evaluating the role of solar variability on Northern Hemisphere temperature trends since the 19th century’ has been rebutted. I don’t see a rebuttal of Soon’s ‘work’ since a bit earlier (eg here) and there is today quite a collection of denialist ‘work’ referencing Soon et al (2015).
    Of course Soon et al (2015) is a rather long ‘work’ running to 49 pages, “running” being the operative word. It doesn’t stop once to properly compare its individual assertions with the actual science it is trying to overturn.
    Perhaps a summary would be in order for folk here to appreciate the labours of these denialist running-dogs.

    (1) Solar variability over recent centuries is discussed at length (pp3-19). The coverage does end with a “Summary of the Current Debates” but this begins badly [saying “Solar input is probably one of the most important drivers of Earth’s climate.”] and anything usefully set out is entirely ignored within the remainder of the ‘work’ which is doing no more than following Scarfetta & Willson (2014).
    (2) A novel ‘composite’ NH land temperature record 1880-to-date is constructed using selective “rural” data from China, USA, Ireland & (less selectively) the Arctic, concluding that it is significantly different from other NH land temperature records (pp19-32).
    (3) While their ‘composite’ NH land temperature record is significantly different from all others, they fail to investigate why this may be so (effectively asserting that it is due to Urbal Heat Islands) and instead compare their ‘composite’ directly with NH SST records, glacier-length records and Wilson et al (2007) ‘A matter of divergence: Tracking recent warming at hemispheric scales using tree ring data’, prividing themselves with a conformatory tick in all cases (pp32-35).
    (4) A quick ‘attribution’ analysis shows their ‘composite’ NH land temperature record is “a remarkably close fit” with their chosen solar variability reconstruction leading to a conclusion “that most of the temperature trends since at least 1881 can be explained in terms of solar variability, with atmospheric greenhouse gas concentrations providing at most a minor contribution” which is entirely contrary to the findings of IPCC AR5 Chapter 10 “Detection and Attributionof Climate Change:from Global to Regional” but which is dismissed as being purely a “claim” (pp37-43).

  8. 158
    John Pollack says:

    Kevin @132 USDA hardiness zones are calculated using the 30-year average of the annual minimum, not the daily minimum.
    Killian @142 Updating the USDA zone map every 5 years makes little sense. You’d be taking the oldest 5 winters off the previous calculation, and adding the most recent 5 winters. The purpose of the map is to help gardeners and growers decide which perennial plants will take the winters in their area. 5 year adjustments make little difference to a planting that’s supposed to last a generation or more. Besides, I’d like you to show me a place outside of Alaska where the 30 year mean winter minimum has warmed at 10F in a decade. In a large part of the Midwest, in fact, it’s gotten colder this decade.

  9. 159
    Nemesis says:

    @mike, #154

    “Has the rate of CO2 increase in the atmosphere slowed or stopped from what you can see?”

    It’s all just rosecolored glasses, I knew it all the time and I know it now and I know it for the future:

    The powers that be were never interested in cutting emissions, they are solely interested in maintaining their wealth and power as long as possible, it’s dead easy to see through em.

    “Ye who enter here leave all hope behind.”

    Dante Alighieri, Divina Commedia

  10. 160
    Hank Roberts says:

    2019/04/29
    TI – Basal melting of Ross Ice Shelf from solar heat absorption in an ice-front polynya
    JO – Nature Geoscience
    AB – Ice–ocean interactions at the bases of Antarctic ice shelves are rarely observed, yet have a profound influence on ice sheet evolution and stability. Ice sheet models are highly sensitive to assumed ice shelf basal melt rates; however, there are few direct observations of basal melting or the oceanographic processes that drive it, and consequently our understanding of these interactions remains limited. Here we use in situ observations from the Ross Ice Shelf to examine the oceanographic processes that drive basal ablation of the world’s largest ice shelf. We show that basal melt rates beneath a thin and structurally important part of the shelf are an order of magnitude higher than the shelf-wide average. This melting is strongly influenced by a seasonal inflow of solar-heated surface water from the adjacent Ross Sea Polynya that downwells into the ice shelf cavity, nearly tripling basal melt rates during summer. Melting driven by this frequently overlooked process is expected to increase with predicted surface warming. We infer that solar heat absorbed in ice-front polynyas can make an important contribution to the present-day mass balance of ice shelves, and potentially impact their future stability.
    SN – 1752-0908
    UR – https://doi.org/10.1038/s41561-019-0356-0
    DO – 10.1038/s41561-019-0356-0
    ID – Stewart2019

  11. 161

    Killian, #142–

    Get used to disappointment, eh?

    Words of wisdom, sadly… though I will say that the last couple of years have provided lots of practice.

    Oh, and nice exposition of climate science and policy at #129, BTW. Engaging and pretty clear.