{"id":88054,"date":"2023-01-10T03:03:00","date_gmt":"2023-01-10T02:03:00","guid":{"rendered":"https:\/\/www.sonnenseite.com\/?p=88054"},"modified":"2023-01-08T11:03:39","modified_gmt":"2023-01-08T10:03:39","slug":"new-method-helps-understand-the-global-organic-carbon-cycle","status":"publish","type":"post","link":"https:\/\/www.sonnenseite.com\/en\/science\/new-method-helps-understand-the-global-organic-carbon-cycle\/","title":{"rendered":"New method helps un\u00adder\u00adstand the global or\u00adganic car\u00adbon cycle"},"content":{"rendered":"\n

Re\u00adsearch\u00aders from the USA, the UK and Bre\u00admen have used a new method to cal\u00adcu\u00adlate the rate at which or\u00adganic car\u00adbon was se\u00adquestered in mar\u00adine sed\u00adi\u00adments dur\u00ading the Earth’s Neo\u00adgene period. It is more ac\u00adcur\u00adate than the pre\u00advi\u00adously used method and can there\u00adfore make an im\u00adport\u00adant con\u00adtri\u00adbu\u00adtion to un\u00adder\u00adstand\u00ading cli\u00admate change and mit\u00adig\u00adat\u00ading its ef\u00adfects. Their res\u00adults have now been pub\u00adlished in the sci\u00adentific journal Nature<\/em>.<\/p>\n\n\n\n

Oceans serve as a sink for car\u00adbon. This means that car\u00adbon from the at\u00admo\u00adsphere is stored in the oceans. However, a dis\u00adtinc\u00adtion is made between or\u00adganic and in\u00ador\u00adganic car\u00adbon. The or\u00adganic car\u00adbon bound in mar\u00adine sed\u00adi\u00adments is also a source of oxy\u00adgen. Un\u00adtil now, it has been com\u00admon prac\u00adtice to de\u00adterm\u00adine the mass bal\u00adance between in\u00ador\u00adganic and or\u00adganic car\u00adbon \u2013 but this method is con\u00adsidered in\u00adac\u00adcur\u00adate. A team from the USA, Great Bri\u00adtain and Ger\u00admany has now de\u00adveloped a dif\u00adfer\u00adent ap\u00adproach. Their goal was to be able to bet\u00adter de\u00adterm\u00adine the rate of car\u00adbon over a longer period of time.<\/p>\n\n\n\n

To do this, they used data from deep-sea drilling at 81 global sites to de\u00adterm\u00adine the his\u00adtory of or\u00adganic car\u00adbon burial dur\u00ading the Neo\u00adgene (about 23 to 3 mil\u00adlion years ago). This ap\u00adproach makes it pos\u00adsible to bet\u00adter de\u00adterm\u00adine the vari\u00adab\u00adil\u00adity over such a long period of time.<\/p>\n\n\n\n

\u201dOur res\u00adults sup\u00adport the as\u00adsump\u00adtion that rates were high in the early Mio\u00adcene and Plio\u00adcene and low in the middle Mio\u00adcene,\u201d ex\u00adplains first au\u00adthor Dr. Ziye Li from MARUM \u2013 Cen\u00adter for Mar\u00adine En\u00advir\u00adon\u00admental Sci\u00adences at the Uni\u00adversity of Bre\u00admen. \u201cWe cal\u00adcu\u00adlated the mass ac\u00adcu\u00admu\u00adla\u00adtion rate of or\u00adganic car\u00adbon dir\u00adectly from the or\u00adganic car\u00adbon con\u00adtent of mar\u00adine sed\u00adi\u00adments. This is pos\u00adsible thanks to stand\u00adard\u00adized meas\u00adure\u00adments com\u00adbined with well val\u00adid\u00adated age mod\u00adels from sites from the in\u00adter\u00adna\u00adtional drilling pro\u00adgram IODP and its pre\u00adde\u00adcessors DSDP and ODP. Tra\u00addi\u00adtion\u00adally, es\u00adtim\u00adates have been based on the iso\u00adtopic com\u00adpos\u00adi\u00adtion of car\u00adbon, which re\u00adquires, among other things, a num\u00adber of as\u00adsump\u00adtions about car\u00adbon sources and key fluxes within the car\u00adbon cycle,\u201d says Li, who works at MARUM in the Low Lat\u00adit\u00adude Cli\u00admate Vari\u00adab\u00adil\u00adity group.<\/p>\n\n\n\n

\u201cOur new res\u00adults are very dif\u00adfer\u00adent \u2013 they are the op\u00adpos\u00adite of what the iso\u00adtope cal\u00adcu\u00adla\u00adtions are sug\u00adgest\u00ading,\u201d says co-au\u00adthor Ben\u00adjamin Mills from the Uni\u00adversity of Leeds, an ex\u00adpert on the es\u00adtab\u00adlished iso\u00adtope meth\u00adods. \u201cI was really sur\u00adprised how wrong our cur\u00adrent ideas might be.\u201d<\/p>\n\n\n\n

Li and her col\u00adleagues as\u00adsume that car\u00adbon se\u00adquest\u00adra\u00adtion, or rather its ab\u00adsence, is re\u00adlated to tem\u00adper\u00adat\u00adure-de\u00adpend\u00adent bac\u00adterial de\u00adcom\u00adpos\u00adi\u00adtion of or\u00adganic mat\u00adter dur\u00ading the warm period of the middle Mio\u00adcene. Thus, this feed\u00adback mech\u00adan\u00adism would be ex\u00adpec\u00adted to play out dur\u00ading other warm\u00ading in\u00adter\u00advals in Earth’s his\u00adtory, as well as in any fu\u00adture warm\u00ading of the global ocean.<\/p>\n\n\n\n

\u201cAs we warm up the ocean, it will make it harder for or\u00adganic car\u00adbon to find its way to be bur\u00adied in the mar\u00adine sed\u00adi\u00adment sys\u00adtem, and that is what we have found in our study \u2013 the low\u00adest rates of car\u00adbon se\u00adquest\u00adra\u00adtion hap\u00adpen when the planet was warm\u201d, said co-au\u00adthor Yige Zhang of Texas A&M Uni\u00adversity. \u201cSo that\u2019s not help\u00ading from this per\u00adspect\u00adive, in terms of the is\u00adsues that we\u2019re fa\u00adcing in the present day.\u201d<\/p>\n\n\n\n

However, the team’s re\u00adsearch sug\u00adgests that this res\u00adpir\u00ada\u00adtion-like pro\u00adcess pre\u00advents or\u00adganic car\u00adbon se\u00adquest\u00adra\u00adtion from re\u00addu\u00adcing car\u00adbon di\u00adox\u00adide emis\u00adsions to the at\u00admo\u00adsphere. When bac\u00adteria pro\u00adcess the or\u00adganic car\u00adbon, it is re\u00adturned to its ori\u00adginal form as CO2.<\/p>\n\n\n\n