Path: ...!2.eu.feeder.erje.net!feeder.erje.net!feeds.news.ox.ac.uk!news.ox.ac.uk!nntp-feed.chiark.greenend.org.uk!ewrotcd!news.eyrie.org!beagle.ediacara.org!.POSTED.beagle.ediacara.org!not-for-mail From: William Hyde Newsgroups: talk.origins Subject: Re: What is YOUR view? Date: Wed, 24 Apr 2024 20:23:24 -0400 Organization: A noiseless patient Spider Lines: 254 Sender: to%beagle.ediacara.org Approved: moderator@beagle.ediacara.org Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Info: beagle.ediacara.org; posting-host="beagle.ediacara.org:3.132.105.89"; logging-data="89303"; mail-complaints-to="usenet@beagle.ediacara.org" User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:91.0) Gecko/20100101 Firefox/91.0 SeaMonkey/2.53.18.2 To: talk-origins@moderators.isc.org Cancel-Lock: sha1:t9qK1vvZKzrXDNCArsd5AadmUHc= Return-Path: X-Original-To: talk-origins@ediacara.org Delivered-To: talk-origins@ediacara.org id 653BE22976C; Wed, 24 Apr 2024 20:23:21 -0400 (EDT) by beagle.ediacara.org (Postfix) with ESMTP id 371C9229758 for ; Wed, 24 Apr 2024 20:23:19 -0400 (EDT) id 5800F5DC2C; Thu, 25 Apr 2024 00:23:42 +0000 (UTC) Delivered-To: talk-origins@moderators.isc.org by mod-relay-1.kamens.us (Postfix) with ESMTPS id 36D9E5DC29 for ; Thu, 25 Apr 2024 00:23:42 +0000 (UTC) id 1E468DC01CA; Thu, 25 Apr 2024 02:23:40 +0200 (CEST) X-Injection-Date: Thu, 25 Apr 2024 02:23:39 +0200 (CEST) X-Auth-Sender: U2FsdGVkX1/F/1scKubopWwdRpSTqr86KJKUe8Nu1Ho= In-Reply-To: Bytes: 12429 RonO wrote: > On 4/7/2024 5:55 PM, William Hyde wrote: >> RonO wrote: >> >>> >>> We are putting out a lot of carbon dioxide into the atmosphere.  Some >>> people worry about methane, but the effect is likely negligible >>> because methane doesn't last very long in the atmosphere. >> >> >> They are right to worry.  The effect of CH4 is about .5 Watts per >> square meter as compared to pre-industrial times.  Crudely speaking, >> this accounts for about a quarter of a degree of warming. >> >> Why is it so?  Well, the mean lifetime of CH4 in the atmosphere is not >> that short, being about 11 years.  As it is far more effective at >> absorbing IR than CO2 it can add a lot of heat before it is gone. >> >> When it does break down, some of it becomes stratospheric water >> vapour, which is an excellent greenhouse gas itself.  And this effect >> lasts. >> >> The effect of a unit of methane put into the atmosphere, over a >> century, is still larger than that of a unit of CO2, though the CH4 >> will be long gone at the end of that period. >> >> It's short lifetime hasn't stopped us from increasing the amount in >> the atmosphere. CO2 levels have not yet doubled from pre-industrial >> times, but CH4 is up 160%. >> >> Finally, the bio-geochemistry of CH4 works against us.  As the world >> warms, microbes more actively devour our stock of sequestered organic >> carbon, producing more CH4 and CO2.  Arctic soils, in particular, hold >> vast amounts of frozen organic matter - far more  than tropical soils. >> Field experiments have shown that the rate at which arctic areas are >> giving off greenhouse gases is increasing. This positive feedback >> could grow very nasty indeed. >> >>   We likely did >>> accelerate global warming with our increased output of carbon >>> dioxide, but we did it at a time when global temperatures had already >>> been increasing for thousands of years. >> >> Time scales matter. >> >> The earth has warmed about 4C since the last glacial maximum about 20k >> years ago, most of that in the first 10k.  We have now warmed the >> earth one degree C in less than two centuries.  And eight billion of >> us depend on the ecosystems which were well adjusted to that earlier >> climate. >> >> It appears that already forests in parts of the world are no longer >> stable ecosystems.  Many will be replaced by more fire-resistant (and >> less useful) trees, or by grass or scrub.   And that's just the >> beginning. >> >> >>> >>> We need to better define what the crisis is. >>> >>> We probably should be nearing the end of the current warming period. >>> For the last million years we have had the 100,000 year ice age >>> cycles. The earth has been cooling for the last 3 million years, but >>> for the last million we went to a cycle of around a hundred thousand >>> years of cold interspersed with 20 to 30 thousand years of warmer >>> climate.  The temperatures of the cycles seem to have become more >>> extreme in the last 500,000 years.  The last warm period got warmer >>> than it is now, and more ice melted and sea levels were 20 meters >>> higher than they are now. >> >> >> Eemian warmth was different.  At this time the orbital eccentricity >> was more than double the current value.  With perihelion occurring in >> summer,  this led to strong increases in summer temperatures, >> decreases in winter.  The obliquity was also larger, meaning more heat >> in higher latitudes. >> >> The problem is that our temperature proxies are mostly summer ones - >> winter does not leave us a lot of records. Tropical records can also >> be difficult to work with, so there is a bias towards temperate and >> polar records.   Eemian warmth is mainly summer warmth, and not >> directly comparable to our little experiment which will be year-round >> warmth, with a bias towards winter and higher latitudes. >> >> And, once more, the Eemian world did not have to support eight billion >> people. >> >> >>    We >>> have not reached that point, yet in this cycle, so things are not yet >>> as bad as they got without human industrial interference. >>> >>> There was an article put up on TO, maybe a decade ago, that claimed >>> that the current carbon dioxide levels could prevent a recession into >>> another ice age. >> >> >> As one of the authors of such a paper, I have to disagree with your >> interpretation. >> >> >> >>    We might delay the next ice age.  This really doesn't seem to >>> be that bad. >> >> >> Nor would it be good.  Ice ages begin very slowly in human terms.  If >> we still are an industrial society when the next one comes along - >> some time in the next twenty thousand years - we will be able to deal >> with it. >> >> Worrying about a future ice age at this point is equivalent to Julius >> Caesar worrying about world war II. >> >> >>   We got a taste of what things would be like when >>> temperatures fell for the mini ice age that started in the 1300's and >>> didn't end until the start of the industrial revolution that is >>> supposed to be responsible for our current global warming. >> >> >> The little ice age ended well before CO2 from industry became a >> significant factor in climate.  It has been shown that stratospheric >> aerosols caused by increased volcanism account for about 60% of the >> little ice age cooling.  Given the noisy data, that's about as good as >> can expect, though solar, GHG and land-use effects were also accounted >> for. >> >> >> >>    The earth has seen >>> warmer climates that had more ice melting and sea levels rising to >>> the levels that they claim may occur this time, but they obviously >>> happened before.  So the regions that will be flooded will just be a >>> repeat of what happened last time a hundred thousand years ago. >> >> You are drawing parallels where there are no parallels.  See above. >> >> >> William Hyde >> > > It looks like you didn't comment relevantly on that topic, just denied > it with no discussion. Really? You started with the claim that methane is not an important greenhouse gas, and I went into some detail to show that it in fact is. Then you went on to speculate that global warming might save us from an oncoming ice age, and I reminded you that while an ice age is coming soon in geological time, it is very far away in human time, while damage from global warming is not. I did not mention ocean acidification, another consequence of our atmospheric pollution. I gather from biologists that this is also rather important. The paper that was put up on TO did predict that > we might skip the next ice age. Actually this is not a new idea. I first saw reference to in in an ========== REMAINDER OF ARTICLE TRUNCATED ==========