{"id":477,"date":"2017-09-20T20:47:36","date_gmt":"2017-09-20T20:47:36","guid":{"rendered":"http:\/\/80.85.86.254\/sjor\/?p=477"},"modified":"2024-10-15T15:06:58","modified_gmt":"2024-10-15T15:06:58","slug":"3-4-losun-grodurhusalofttegunda","status":"publish","type":"post","link":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/2017\/09\/20\/3-4-losun-grodurhusalofttegunda\/","title":{"rendered":"3.4 Losun gr\u00f3\u00f0urh\u00fasalofttegunda"},"content":{"rendered":"

Magn gr\u00f3\u00f0urh\u00fasalofttegunda \u00ed andr\u00famsloftinu hefur aukist gr\u00ed\u00f0arlega fr\u00e1 i\u00f0nbyltingu. Aukningin hefur veri\u00f0 s\u00e9rlega hr\u00f6\u00f0 fr\u00e1 1950. Fyrir i\u00f0nbyltingu var styrkur kold\u00edox\u00ed\u00f0s um 280 ppm en er n\u00fa kominn yfir 420 ppm. En kold\u00edox\u00ed\u00f0 er ekki eina gr\u00f3\u00f0urh\u00fasalofttegundin sem hefur aukist \u00ed andr\u00famsloftinu. Styrkur metans og gla\u00f0lofts hefur l\u00edka aukist miki\u00f0 og \u00e1 mj\u00f6g svipa\u00f0an h\u00e1tt. \u00de\u00e1 hefur styrkur annarra gr\u00f3\u00f0urh\u00fasalofttegunda aukist, n\u00e1nar tilteki\u00f0 lofttegunda sem innihalda fl\u00faor (F-g\u00f6s), en \u00fe\u00e6r lofttegundir voru ekki til fyrr en fari\u00f0 var a\u00f0 b\u00faa \u00fe\u00e6r til \u00ed verksmi\u00f0jum viljandi e\u00f0a \u00f3vart (hli\u00f0arafur\u00f0ir). Allar \u00feessar lofttegundir eiga \u00fe\u00e1tt \u00ed a\u00f0 auka gr\u00f3\u00f0urh\u00fasa\u00e1hrif og valda loftslagsbreytingum. \u00dea\u00f0 er hins vegar kold\u00edox\u00ed\u00f0 sem hefur langmest \u00e1hrif (samtals um 76% af heildar\u00e1hrifunum) eins og s\u00e9st \u00e1 mynd 3.5.
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\nBrennsla jar\u00f0eldsneytis er eins og \u00e1\u00f0ur sag\u00f0i st\u00e6rsta uppspretta losunar kold\u00edox\u00ed\u00f0s. Jar\u00f0eldsneyti er brennt m.a. til a\u00f0 framlei\u00f0a rafmagn og hita sem og til a\u00f0 kn\u00fdja skip, flugv\u00e9lar og b\u00edla. Einnig losnar kold\u00edox\u00ed\u00f0 \u00ed i\u00f0na\u00f0i, t.d. vi\u00f0 framlei\u00f0slu \u00e1ls og k\u00edsils. \u00de\u00e1 losnar kold\u00edox\u00ed\u00f0 \u00feegar sk\u00f3gum er eytt og \u00feegar land er rutt til a\u00f0 vinna landb\u00fana\u00f0arland.<\/p>\n

Metan losnar a\u00f0allega \u00fat \u00ed andr\u00famslofti\u00f0 vegna vinnslu jar\u00f0eldsneytis, d\u00fdrahalds og vegna ur\u00f0unar \u00fargangs. Vi\u00f0 framlei\u00f0slu og flutning \u00e1 kolum, ol\u00edu og jar\u00f0gasi losnar metan \u00fat \u00ed andr\u00famslofti\u00f0. Metan myndast \u00ed meltingarvegi d\u00fdra, s\u00e9rstaklega j\u00f3rturd\u00fdra. Metan myndast einnig \u00e1 ur\u00f0unarst\u00f6\u00f0um \u00feegar \u00fargangurinn brotnar ni\u00f0ur \u00ed s\u00farefnis\u00feurr\u00f0. M\u00f6gulegt er a\u00f0 safna og n\u00fdta hluta \u00feess metans sem myndast \u00e1 ur\u00f0unarst\u00f6\u00f0um.<\/p>\n

Gla\u00f0loft myndast m.a. vegna \u00e1bur\u00f0arnotkunar \u00ed landb\u00fana\u00f0i en getur einnig myndast vi\u00f0 framlei\u00f0slu \u00e1bur\u00f0ar \u00ed efnaverksmi\u00f0jum. \u00de\u00e1 myndast einnig gla\u00f0loft \u00feegar eldsneyti er brennt.<\/p>\n

Sum F-g\u00f6s myndast sem hli\u00f0arafur\u00f0 \u00feegar veri\u00f0 er a\u00f0 framlei\u00f0a a\u00f0rar afur\u00f0ir \u00ed verksmi\u00f0jum (t.d. PFC \u00ed \u00e1lverum). \u00d6nnur F-g\u00f6s eru b\u00fain til \u00ed \u00e1kve\u00f0num tilgangi, t.d. til a\u00f0 nota \u00ed k\u00e6lii\u00f0na\u00f0i. F-g\u00f6sin geta losna\u00f0 \u00fat \u00ed andr\u00famslofti\u00f0 b\u00e6\u00f0i vi\u00f0 framlei\u00f0slu og notkun.<\/p>\n

Losun gr\u00f3\u00f0urh\u00fasalofttegunda af mannav\u00f6ldum hefur sem fyrr segir aukist miki\u00f0 fr\u00e1 upphafi i\u00f0nbyltingar, l\u00edkt og sj\u00e1 m\u00e1 \u00e1 mynd 3.6.<\/p>\n