by
Satellittmåling viser liten økt drivhuseffekt
- mai 15, 2021
- 18:54
- Geir Aaslid
- Kategorier: Atmosfærefysikk, CO2-utslipp
Klimanytt nr. 297. Redaktør: Ole Henrik Ellestad.
Forfattet av Ole Henrik Ellestad.
Satellittobservasjoner og beregninger av strålingseffekten av økte drivhusgasser viser liten økning, som utelukkende har positive virkninger. Da er det ikke klimakrise, men klimaforbedring.
I 200 år har laboratorieeksperimenter vist at gasser kan oppvarmes av stråling. I 160 år har vi visst at vanndamp er en meget sterk drivhusgass, CO2 bidrar litt, mens ozon, metan og lystgass i enda mindre grad bidrar til oppvarming (J. Tyndall 1859, KN 270). Teorien var velutviklet i midten av 1930-årene, de ledende meteorologer mente dette fra 1950-tallet (KN 194), og satellittmålinger og tilhørende beregninger viste dette fra 1970-årene (se nedenfor).
For hvert nytt molekyl som tilføres atmosfæren blir molekyleffekten mindre (logaritmisk utvikling). Mens de første 20 ppm (part per million) gir ca. 1.7 C vil 20 ppm på dagens nivå bare gi ca. 0.06 C. Så atmosfæren er nå tilnærmet mettet, som en våt svamp som kan ta opp bare litt mer damp. Studentene lærer det tidlig i kurset, alle innen feltet vet det, og det er omtalt langt inne i fagdelene av IPCC-rapportene. Men det står ikke i sammendragene og formidles ikke i medier og mange fagartikler. For de som gjør det betegnes fornektere.
Heller ikke Arrhenius tidligere beregninger eller datamaskinene med sine simuleringsmodeller fra 1970-80-årene endret den rådende vitenskapelige oppfatning. Ikke før IPCC ble etablert som en politisk, rådgivende organisasjon (1988). Da eskalerte klimaproblemene raskt til store, alarmerende høyder basert på store beregningsmodeller. Men drivhusgassenes strålingsbidrag kan beregnes meget godt for steder med kjente atmosfæriske forhold, minst like godt som med IPCC-modellene. Da er økt drivhuseffekt liten og fordelaktig.
Emisjon av jordstråling kan beregnes godt
Utstrålt energi fra jordoverflaten (langbølget infrarød stråling, ORL) til verdensrommet er siden 1883 beregnet med Stefan-Boltzmanns lov (KN 291) basert på den aktuelle overflatetemperatur (-90 til +60 C). Basert på kjennskap til atmosfæregassenes infrarøde spektrum kan absorpsjon og emisjon beregnes godt når strålingen passerer gjennom atmosfæren. Figuren under viser utstrålingen fra toppen av atmosfæren en skyfri dag over Guam (Stillehavet) i 1970 (326 ppm CO2). Energien er målt fra NIMBUS 4 satellitt (heltrukken, takkete linje, Michelson interferometer). Svakt prikket linje, som følger tett på den takkete, er beregnet emisjon med datidens database (HITRAN, US Air Force, i dag forbedret og supplert av databasen VAMDC). Kun H2O og CO2 er med i beregningene. Toppen betegnet O3 (ca. 1050 cm-1) skyldes ozon.
Så når man kjenner jordoverflatens temperatur og atmosfærens parametre kan man for klar himmel beregne atmosfæriske effekter fra absorpsjon og emisjon av infrarød stråling meget godt, i dag enda bedre enn over Guam.
Liten beregnet effekt fra økt CO2
Hva kan dette brukes til? Mengden drivhusgasser, atmosfæriske betingelser, utstrålingstemperatur fra bakken osv. kan endres og tilhørende effekter beregnes. Noen slike variasjoner for dagens situasjon er vist i neste figur som har stor likhet med den over. Den viser beregnet effekt av standard mengde drivhusgasser i atmosfæren (sort kurve med angivelse i hvilke frekvensområder gassene har effekt) opp til 86 km høyde (toppen av mesosfæren). Standard konsentrasjon i alle kurver ved havoverflaten er 7750 ppm H2O, 1.8 ppm CH4, 0.36 ppm N2O. Endringer i CO2-konsentrasjonen påvirker utstrålingen (Grønn kurve null CO2, sort kurve 400 ppm, og rød kurve 800 ppm). Blå kurve er beregnet utstråling fra jordoverflaten (Planck-stråling).
Energien som ut ifra figuren er tilført atmosfæren og kan lede til temperaturøkning, representeres ved arealet mellom utstrålingskurven fra bakken (Planck-kurven, blå) og utstrålingskurvene fra mesosfæren (takkede linjer sort, rød, grønn). Forskjellen skyldes atmosfærens avtagende temperatur med høyden (‘lapse rate’). Ved økt CO2-mengde emitteres ved høyere nivå som har lavere temperatur og derved mindre effektiv emisjon (Kirchhoffs lov 1859/Schwartzschilds ligning 1916). Effekten av dobling av CO2 er arealet mellom den røde og sorte kurve. Dersom det er temperaturinversjon i atmosfæren vil økt CO2-mengde lede til økt utstråling og avkjøling (Antarktis).
Dobling av nåværende mengder av CO2, N2O og CH4 øker samlet effekt bare med inntil et par prosent. Dagens konsentrasjoner av CF4/KFK og SF6 er meget små og gir ingen merkbar effekt. Selv med 100 ganger økning blir effekten mindre enn ved dobling av CO2-konsentrasjonen. Molekylenes spektra overlapper og målt totaleffekt er mindre enn summen av effekten av hvert av molekylene om de er alene. Spesielt gjelder dette for effekten av metan som dempes sterkt av vanndamp.
Fra områdene merket H2O ser man vanndampens store betydning og at økte vanndampmengder har liten effekt. Vanndampen foreligger i så store mengder at den med unntak av meget kalde områder er mettet.
Konklusjon
CO2 er en svak drivhusgass som over 200 ppm er på vei til å bli mettet med liten ytterligere effekt. Om CO2 var alene ville effekten av dobling være ca. 1 C for dagens situasjon. Det er ingen forsterkning, snarere er det påvist negative tilbakekoblinger som reduserer CO2s effekt. Ozon, metan, lystgass, og fluor- forbindelser har liten effekt (KN 270, Gavin Smith et al. 2019).
The start of a fast-growing trend?
Hi, do have a e-newsletter? In the event you don’t definately should get on that piece…this web site is pure gold!
I’ve read several good stuff here. Definitely worth bookmarking for revisiting. I surprise how much effort you put to make such a magnificent informative site.
Fantastic piece of writing here1
you may have an ideal blog here! would you prefer to make some invite posts on my blog?
Very fine blog.
My coder is trying to convince me to move to .net from PHP. I have always disliked the idea because of the expenses. But he’s tryiong none the less. I’ve been using WordPress on numerous websites for about a year and am nervous about switching to another platform. I have heard great things about blogengine.net. Is there a way I can import all my wordpress posts into it? Any help would be really appreciated!
Bạn thật tài năng! Bài viết này thật sự rất ấn tượng. Tôi đã học được rất nhiều điều mới từ những chia sẻ của bạn. Tôi sẽ chia sẻ bài viết này với bạn bè của mình.
This blog post is excellent, probably because of how well the subject was developed. I like some of the comments too though I could prefer we all stay on the subject in order add value to the subject!
Unquestionably believe that which you said. Your favorite reason seemed to be on the net the easiest thing to be aware of. I say to you, I certainly get annoyed while people consider worries that they plainly don’t know about. You managed to hit the nail on the head. Will probably be back to get more. Thanks
Hi my family member! I want to say that this article is amazing, great written and include approximately all important infos. I’d like to see more posts like this .
nice blog! keep write!
I’ll check back after you publish more articles.
Porn
This is one very informative blog. I like the way you write and I will bookmark your blog to my favorites.
Thanks for your patience and sorry for the inconvenience!
Thanks a bunch for sharing this with all people you really recognize what you are talking about! Bookmarked. Kindly also seek advice from my web site =). We can have a link alternate contract between us!
It is perfect time to make some plans for the future and it is time to be happy. I’ve read this post and if I could I want to suggest you some interesting things or suggestions. Perhaps you can write next articles referring to this article. I wish to read more things about it!
Sex
Porn
I just added your web site to my blogroll, I hope you would look at doing the same.
Howdy! I simply wish to give a huge thumbs up for the great information you have here on this post. I will be coming again to your weblog for extra soon.
I’ve been surfing online more than three hours today, yet I never found any interesting article like yours. It is pretty worth enough for me. In my view, if all webmasters and bloggers made good content as you did, the web will be a lot more useful than ever before.
You are good writer. Thank you.
Simply wish to say the frankness in your article is surprising.
Its just like you read my thoughts! It’s like reading about my family.
It is my belief that mesothelioma can be the most deadly cancer. It’s got unusual qualities. The more I really look at it the harder I am convinced it does not conduct itself like a true solid cells cancer. In the event that mesothelioma is usually a rogue viral infection, hence there is the chance for developing a vaccine in addition to offering vaccination for asbestos uncovered people who are at high risk involving developing potential asbestos associated malignancies. Thanks for sharing your ideas about this important health issue.
Well, I don’t know if that’s going to work for me, but definitely worked for you! 🙂 Excellent post!
whoah this blog is great i love reading your posts. Keep up the great work! You know, a lot of people are hunting around for this info, you can help them greatly.
I imagine so. Very good stuff, I agree totally.
Thanks so much for this, keep up the good work 🙂
Terrific work! That is the kind of info that are meant to be shared across the internet. Shame on the search engines for now not positioning this post upper! Come on over and seek advice from my website . Thanks =)
Are grateful for this blog post, it’s tough to find good information and facts on the internet
That’s some inspirational stuff. Never knew that opinions might be this varied. Thanks for all the enthusiasm to supply such helpful information here.
We are a group of volunteers and starting a new initiative in our community. Your blog provided us with valuable information to work on|.You have done a marvellous job!
메이저슬롯
Greetings! I know this is kind of off topic but I was wondering which blog platform are you using for this site? I’m getting tired of WordPress because I’ve had issues with hackers and I’m looking at options for another platform. I would be awesome if you could point me in the direction of a good platform.
Just want to say what a great blog you got here!I’ve been around for quite a lot of time, but finally decided to show my appreciation of your work!
This is really interesting, You’re a very skilled blogger. I have joined your feed and look forward to seeking more of your great post. Also, I’ve shared your web site in my social networks!
What made you first develop an interest in this topic?
A thoughtful insight and ideas I will use on my blog. You’ve obviously spent some time on this. Congratulations
A person essentially help to make seriously posts I would state. This is the first time I frequented your web page and thus far? I surprised with the research you made to make this particular publish amazing. Magnificent job!
Oh my goodness! an amazing article. Great work.
What i discover troublesome is to find a weblog that may capture me for a minute however your blog is different. Bravo.
Have you given any kind of thought at all with converting your current web-site into French? I know a couple of of translaters here that will would certainly help you do it for no cost if you want to get in touch with me personally.
I discovered your weblog site on google and verify just a few of your early posts. Proceed to maintain up the very good operate. I simply further up your RSS feed to my MSN News Reader.
Pretty nice post. I just stumbled upon your weblog and wanted to say that I’ve really enjoyed surfing around your blog posts. After all I’ll be subscribing in your feed and I am hoping you write again very soon!
Thanks for this article. I might also like to say that it can often be hard if you are in school and just starting out to create a long history of credit. There are many college students who are just trying to pull through and have a protracted or favourable credit history are often a difficult matter to have.
I discovered your weblog site on google and verify just a few of your early posts. Proceed to maintain up the very good operate. I simply further up your RSS feed to my MSN News Reader.
Today, taking into consideration the fast chosen lifestyle that everyone is having, credit cards get this amazing demand throughout the market. Persons coming from every discipline are using credit card and people who are not using the credit card have made up their minds to apply for 1. Thanks for sharing your ideas in credit cards.
Howdy, a helpful article for sure. Thank you.
Whoa! This blog looks just like my old one! It’s on a completely different topic but it has pretty much the same layout and design. Great choice of colors!
I think this is one of the most vital information for me. And i am glad reading your article. But should remark on some general things, The site style is ideal, the articles is really great : D. Good job, cheers
Nice post.Very useful info specifically the last part 🙂 Thank you and good luck.
I believe this web site has some really wonderful info for everyone : D.
I can’t go into details, but I have to say its a good article!
Its just like you read my thoughts! It’s like reading about my family.
Please let me know if you’re looking for a author for your blog. You have some really great articles and I feel I would be a good asset. If you ever want to take some of the load off, I’d absolutely love to write some content for your blog in exchange for a link back to mine. Please send me an e-mail if interested. Regards!
Appreciation for taking the time to discuss this topic, I would love to discover more on this topic. If viable, as you gain expertise, would you object to updating the website with further information? It is tremendously beneficial for me.
Thanks for another great post. Where else may anybody get that type of info in such an ideal way of writing? I have a presentation next week, and I’m at the search for such information.
Hey there, You have done a great job. I?ll definitely digg it and personally suggest to my friends. I am confident they will be benefited from this site.
Wow that was odd. I just wrote an incredibly long comment but after I clicked submit my comment didn’t show up. Grrrr… well I’m not writing all that over again. Anyway, just wanted to say fantastic blog!
fantastic points altogether, you just won a emblem new reader. What might you suggest in regards to your put up that you made some days ago? Any sure?
Advanced reading here!
Pretty impressive article. I just stumbled upon your site and wanted to say that I have really enjoyed reading your opinions. Any way I’ll be coming back and I hope you post again soon.
Thanks for your article. I would also love to say that your health insurance agent also works for the benefit of the particular coordinators of your group insurance policy. The health insurance broker is given a listing of benefits desired by anyone or a group coordinator. Such a broker does indeed is find individuals or maybe coordinators that best go with those requirements. Then he offers his referrals and if both parties agree, the broker formulates binding agreement between the two parties.