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> "In addition, the year 2020 was exceptionally hot from early spring to late summer over northern Eurasia, a sensitive region for CH4 emissions from biogenic s
by photochemsyn 4y ago
> "In addition, the year 2020 was exceptionally hot from early spring to late summer over northern Eurasia, a sensitive region for CH4 emissions from biogenic sources such as wetlands, permafrost slumps and arctic lakes, which are expected to emit more CH4 as the temperature increases."
I wish people would be realistic and just admit that the tipping point for climate is in the past - because even if there was complete elimination of fossil fuel use in the next decade (highly unlikely), polar warming has resulted in permafrost melt, so that's going to keep dumping carbon to the atmosphere at a slow steady rate. At best, elimination of fossil fuels over the next 3-5 decades will only result in slower warming over the last few decades of the 21st century. We also haven't even come close to realizing warming from the past 5 decades, as the time-to-equilibrium for current forcing is ~100 years. This means a return to climate conditions last seen 3-5 million years ago, during the Pliocene.
Practically, this means as much will have to be spent on adaptation to new conditions as will have to be spent on transition to a non-fossil energy system.
- tony_cannistra 4y agoI'm not aware of any evidence of this, actually. Can you point to some?
- photochemsyn 4y agoSearch Google Scholar for "committed warming" for a quick intro. For example: > "We have asked the illustrative but specific question of should atmospheric greenhouse gases suddenly stop increasing, what additional global warming will occur based on current understanding? Such a constant composition commitment is less ambitious than the recent aspiration of many to achieve “net-zero” global emissions of GHGs. Net-zero has been generally defined as not including natural sinks and is only achieved when anthropogenic CO2 emissions are balanced globally by anthropogenic removals. " (2020) "CMIP6 climate models imply high committed warming" Read the paper at sci-hub, check the references for more. https://sci-hub.se/10.1007/s10584-020-02849-5 https://sci-hub.se/10.1007/s10584-020-02849-5 As this paper notes, > "...there is often a misunderstanding in society, corresponding to a belief that achieving constant atmospheric GHG composition implies that global mean temperatures will not change from that point forward." Note also that these models are generally not including the non-anthropogenic feedback process, such as permafrost melt and carbon release, and the relatively uncertain but potentially very large effects of methane release from shallow marine sediments due to warming polar oceans.
- egberts1 4y agoNot evidence of OP's trend but authoritative data on Ice Shelf Index by GSFC at NASA. https://earth.gsfc.nasa.gov/cryo/data/current-state-sea-ice-cover https://earth.gsfc.nasa.gov/cryo/data/current-state-sea-ice-...
- egberts1 4y agoDr. Claire Parkinson, eminent NASA ice shelf expert, creator of mapping ice shelf by satellite since 1970s. Still claims that ice shelf extents are within historical norms. https://science.gsfc.nasa.gov/sed/bio/claire.l.parkinson https://science.gsfc.nasa.gov/sed/bio/claire.l.parkinson
- mistrial9 4y agoeach of the IPCC, World Meteorological Association, US Global Change Study and the California Climate Reports, contain specifics on this .. a list most recent publications with citations next up?
- culi 4y agoNot sure what your point is. The very first IPCC report (1.5°C) completely ignored permafrost.[^0] They basically admitted they didn't have data on it so they will just ignore the effect altogether. The IPCC reports that followed have all been increasingly grim. In large part, imo, because they stopped ignoring permafrost [^0]: IPCC chapter 2: > The reduced complexity climate models employed in this assessment do not take into account permafrost or non-CO2 Earth system feedbacks, although the MAGICC model has a permafrost module that can be enabled. Taking the current climate and Earth system feedbacks understanding together, there is a possibility that these models would underestimate the longer-term future temperature response to stringent emission pathways (Section 2.2.2).
- egberts1 4y agoIs this the same IPCC that strongly claimed "nuclear energy" is bad in 2009, and now are strongly advocating the use of nuclear energy in 2022?
- culi 4y agoInteresting! Do you have a link to IPCC's anti-nuclear stances in 2009? Genuinely would like to read more, but having a hard time finding it
- mistrial9 4y ago... about halfway through searching a pile of reports.. so far all of these mention a permafrost/wetlands amplification cycle Special Supplement to the Bulletin of the American Meteorological Society Vol. 100, No. 9, September 2019 (see also 2015) Blunden, J. and D. S. Arndt, Eds., 2019: State of the Climate in 2018. Bull. Amer. Meteor. Soc., 100 (9), Si–S305, doi:10.1175/2019BAMSStateoftheClimate.1 Chapter 19 Climate Change -- Evidence & Causes An overview from the Royal Society & the US National Academy of Sciences, 2014 (paid for partly with Sackler Money !! cannot make this up) THE UNDERSTATEMENT OF EXISTENTIAL CLIMATE RISK BY DAVID SPRATT & IAN DUNLOP 2017. Revised and updated August 2018. D E P A R T M E N T O F D E F E N S E C L I M AT E C H A N G E ADAPTATION ROADMAP 2014 Climate Change and the Electricity Sector: Guide for Climate Change Resilience Planning September 2016 U.S. Department of Energy Office of Energy Policy and Systems Analysis --
- scythe 4y agoWell, there's still iron-salt aerosol geoengineering for atmospheric methane removal. Big bet, though.
- winReInstall 4y agoRather prefer space based foil-solar sail ice cap shielding and artifically growing glaciers near south and northpole..
- hedora 4y agoOr, direct air carbon capture. Getting to net zero would cost ~ $1 / gallon of gasoline (and equivalent for other things that emit.) I think we should be paying ~ twice that, minimum. It's far less risky than trying to block out the sun.
- winReInstall 4y agoGrowing massive amounts of seaweed near the ocean top and then sink it into deep waters?
- M95D 4y agoSeaweed mostly floats. Dead seaweed gets degraded by bacteria (just like everything else) and the carbon returns to the atmosphere.
- winReInstall 4y agoUnless you would create a elevator that takes it down to the sea floor..
- deleted 4y ago[deleted]