For the first time, scientists have detected the “fingerprint” of human-induced climate change on daily weather patterns at the global scale. If verified by subsequent work, the findings, published Thursday in Nature Climate Change, would upend the long-established narrative that daily weather is distinct from long-term climate change. The study’s results also imply that research aimed at assessing the human role in contributing to extreme weather events such as heat waves and floods may be underestimating the contribution. Santa Fe, New Mexico, USA twitter: @Merle_Lefkoff ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com archives back to 2003: http://friam.471366.n2.nabble.com/ FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove |
I'd like to read the paper, but it's pay-walled so I realise my comments are on very thin ice. But I do accept that since the mini ice age the global temperatures have been rising and CO2 levels caused by human activities have also been rising and also contribute to the increase in temperatures. So I'm happy to accept the findings of a paper that claims to detect the fingerprints of externally driven climate change. On the other hand, looking at historical global temperatures (much longer than since the end of the mini ice age), I don't think there are solid arguments that only human actions cause climate change. Earth has gone through "hot house" periods and "snowball" periods with no humans burning fossil fuels. A mere thousand years ago the Vikings lived in Greenland and it's too cold there now for the lifestyle they had. The million dollar question is how much? To what extent does CO2 contributes to global warming. The IPCC published a figure of between 1.5 and 4.5 for the "climate sensitivity". This is the increase in global temperature for each doubling of CO2 levels. If it is close to 1,5, we don't have anything to worry about, if it's close to 4.5 then we should stop burning fossil fuels now. The best empirical evidence I could find for the value of climate sensititvity is from the paper by Lewis and Curry https://journals.ametsoc.org/doi/10.1175/JCLI-D-17-0667.1. and they find it to be closer to 1.5. My conclusion is, yes, burning fossil fuels does increase global temperatures and I support the efforts of the likes of Bill Gates doing his utmost to find an "energy miracle" to provide abundant clean energy sources. But personally I'm not ready to start panicking about climate change. I'd rather support the copenhagenconsensus.com approach. I quote "The Copenhagen Consensus Center is a think tank that researches the smartest solutions for the world's biggest problems, advising policy-makers and philanthropists how to spend their money most effectively." By all means, include climate change as a risk, it undoubtedly is , but IMO it's wise to keep a balance about other existential risks too, and do proper cost and benefits analyses for different risks and actions. Pieter Steenekamp Mossel Bay, South Africa On Tue, 7 Jan 2020 at 06:56, Merle Lefkoff <[hidden email]> wrote:
============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com archives back to 2003: http://friam.471366.n2.nabble.com/ FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove |
For you, Pieter: https://twitter.com/i/status/1211631520760221696 On Mon, Jan 6, 2020 at 11:21 PM Pieter Steenekamp <[hidden email]> wrote:
Santa Fe, New Mexico, USA twitter: @Merle_Lefkoff ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com archives back to 2003: http://friam.471366.n2.nabble.com/ FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove |
Thank you Merle, I do appreciate your reply. I followed the link and it found that it is a comment on the ultimate UN source document https://wedocs.unep.org/bitstream/handle/20.500.11822/30797/EGR2019.pdf. I don’t think the report says anything at all in the context of the argument I’m making. The report implicitly assumes the acceptance of the generally accepted view that the current level of greenhouse gas emissions will result in harmful increases in global temperatures. Now what does the physical science in the IPCC actually reports say about this? The latest IPCC report that evaluates the basic science is “AR5”, finalized in 2014, AR6 is scheduled for 2022. I quote from AR5: “The equilibrium climate sensitivity quantifies the response of the climate system to constant radiative forcing on mult-century time scales. It is defined as the change in global mean surface temperature at equilibrium that is caused by a doubling of the atmospheric CO2 concentration, Equilibrium climate sensitivity is likely in the range 1.5 degC to 4.5 degC (high confidence)” Now I’m an engineer who has done extensive work in modelling. (Granted, zero work on climate models. But I do claim professional experience in mathematical modeling of physical systems.) I always try to validate the models - seeking empirical evidence to support the models. I’ve done research to try to find empirical evidence that validates the IPCC quoted climate models. The best I could find is from the published paper I referred to above that found empirical evidence for the climate sensitivity close to the lower range of the IPCC reports. (https://journals.ametsoc.org/doi/10.1175/JCLI-D-17-0667.1.) So, I don’t find anything in your link the refutes the following: a) The latest IPCC published information is that the models indicate that doubling of CO2 causes temperatures to increase in the range of between 1.5 to 4.5 degC. b) The best published empirical (as opposed to modelling) evidence is that this figure is likely to be close to 1.5 If this value is true, we have no reason to be concerned about fossil fuels causing global warming. What do I miss? On Tue, 7 Jan 2020 at 20:06, Merle Lefkoff <[hidden email]> wrote:
============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com archives back to 2003: http://friam.471366.n2.nabble.com/ FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove |
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