\nThe hydrosphere includes all water-covered areas such as rivers, lakes, oceans, and also groundwater and pore water in rock layers.
\nThe biosphere encompasses all areas of Earth inhabited by life \u2013 and it is where the CO\u2082 cycle primarily takes place.<\/strong>
\nThe stratosphere, containing the ozone layer, must be examined separately with regard to its CO\u2082 content.<\/p>\n
![\"Erdsph\u00e4ren\"](\"https:\/\/earthguardian.earth\/wp-content\/uploads\/2025\/07\/Sphaeren-EN.jpg\" "\\"Erdsph\u00e4ren\\"")
<\/p>\n
Where Does the CO\u2082 from Photosynthesis Go?<\/h2>\n
Atmosphere: The Central Exchange Hub<\/strong> Biosphere: More Than Just Above-Ground Vegetation<\/strong> Pedosphere: The Active Underground Carbon Sink Lithosphere: The Giant Long-Term Storage Hydrosphere: The Oceanic Buffer Quantified Carbon Allocation Rhizodeposition Defined:<\/strong> Fate of Rhizodeposited Carbon:<\/strong> Time Scales of Carbon Storage: Exchange Intensity:<\/p>\n Lithosphere: No relevant natural exchange at climate-relevant scales Complete Carbon Budget: Global Flow Between Spheres:<\/p>\n Plants allocate ~50 gigatons of carbon annually into the pedosphere, via:<\/p>\n <\/p>\n Loss from the Pedosphere: The pedosphere is not a subset of the lithosphere \u2014 it is a dynamic, distinct Earth sphere with climate-relevant functions:<\/p>\n 19% of photosynthetic carbon enters the pedosphere, where it\u2019s actively processed \u2014 this fact is crucial for understanding the global carbon cycle. <\/p>\n Author: Francesco del Orbe \ud83c\udf0d<\/p>\n","protected":false},"excerpt":{"rendered":" \u2013 Where Does the CO\u2082 from Photosynthesis End Up? From outer space to Earth\u2019s core, the planet is divided into distinct spheres, each characterized by unique material or physical properties: soil, rock, water, air, ice, etc., all of which interact and influence one another. The atmosphere is the layer of gases surrounding Earth. In daily…<\/p>\n","protected":false},"author":54,"featured_media":23511,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[182,185,605,196],"tags":[261,253,254,263,307,267,260,255,430,429,264,265,252,250,259,262,268,308,207,266],"class_list":["post-23510","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-agriculture","category-climate-and-environment","category-europe-and-the-world","category-guardian-of-the-earth","tag-biodiversity","tag-carbonneutral","tag-climate-action","tag-climate-change","tag-climate-farm","tag-climate-protection","tag-co2-binding","tag-earth-guardian","tag-earthguardian","tag-earthprint","tag-ecosystem","tag-farming","tag-francesco-del-orbe","tag-fresopolis","tag-healthy-soil","tag-microclimate","tag-planting","tag-regenerative-agricultura","tag-sustainability","tag-sustainable"],"acf":[],"yoast_head":"\n
\nThe atmosphere contains 875 gigatons of carbon in the form of CO\u2082 and acts as the central hub, exchanging carbon with all other spheres. It is directly connected to vegetation-based CO\u2082 uptake via photosynthesis.<\/p>\n
\nThe biosphere includes 550 gigatons of carbon stored in aboveground vegetation in the toposphere. However, 46% of total terrestrial carbon fixation is allocated belowground\u2014representing 24.7 gigatons annually.<\/p>\n
\n<\/strong>Often considered a part of the lithosphere or the crust, the pedosphere stores 1,600 gigatons of carbon in organic matter \u2014 making it Earth\u2019s largest terrestrial carbon pool. It acts as an independent and dynamic sphere in direct exchange with the atmosphere.<\/p>\n
\n<\/strong>The lithosphere stores over 66 million gigatons of carbon (mainly as carbonate rock) and around 4,000 gigatons as fossil fuels. This carbon remains locked for geological timescales and is only released by human activities or rare geological events.<\/span><\/p>\n
\n<\/strong>The oceans contain 38,000 gigatons of carbon, exchanging around 70 gigatons per year with the atmosphere, buffering CO\u2082 fluctuations.<\/p>\nThe Critical Moment: Carbon Transfer from the Toposphere to the Pedosphere<\/h2>\n
\n19% of photosynthetic production is transferred into the soil as rhizodeposition, equivalent to ~166 kg of carbon per hectare per season for wheat \u2014 highlighting the significance of root-mediated carbon input.<\/p>\n
\nDifferent forms of carbon enter the pedosphere via rhizodeposition, including:<\/p>\n\n
\nOut of the 19% carbon from rhizodeposition:<\/p>\n\n
![\"\"](\"https:\/\/earthguardian.earth\/wp-content\/uploads\/2025\/07\/Photosynthese.jpg\")
<\/p>\nWhy the Pedosphere Is Not Part of the Lithosphere<\/h2>\n
\nLithosphere: Carbon resides for millions to hundreds of millions of years
\nPedosphere: 15\u2013255 years, depending on climate zone \u2013 global average: 23 years<\/p>\n
\nPedosphere: Highly active \u2013 annual release of 68 gigatons of CO\u2082 from soils, about 1.8\u00d7 fossil fuel emissions<\/p>\n\n\n
\n Process<\/td>\n Annual Flow<\/td>\n Direction<\/td>\n<\/tr>\n \n Photosynthesis<\/td>\n 120 Gt<\/td>\n Toposphere \u2192 Pedosphere<\/td>\n<\/tr>\n \n Plant respiration<\/td>\n 120 Gt<\/td>\n Vegetation (Toposphere) \u2192 Atmosphere (Toposphere)<\/td>\n<\/tr>\n \n Rhizodeposition<\/td>\n 50 Gt<\/td>\n Vegetation (Toposphere) \u2192 Pedosphere<\/td>\n<\/tr>\n \n Ocean exchange<\/td>\n 70 Gt<\/td>\n Hydrosphere \u2194 Atmosphere (Toposphere)<\/td>\n<\/tr>\n \n Fossil fuel combustion<\/td>\n 37 Gt<\/td>\n Lithosphere \u2192 Atmosphere\/Stratosphere<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Key Transfer:\u00a0 Toposphere Vegetation \u2192 Pedosphere<\/h3>\n
\n
Human Impact on This System<\/h2>\n
\nSince the dawn of agriculture, soils have lost an estimated 133 gigatons of carbon, roughly 8% of global soil carbon reserves.
\nTillage increases soil CO\u2082 by 45\u201351% compared to no-till systems.
\nLithosphere Emissions:
\nFossil fuel combustion releases 37.4 gigatons of CO\u2082 annually, roughly 0.55\u00d7 the amount from natural soil respiration.<\/p>\nConclusion: The Pedosphere as a Distinct Climate-Relevant Sphere<\/h3>\n
\n
\nFailing to distinguish the pedosphere from the lithosphere obscures key mechanisms vital to climate strategy.
\nOnly by recognizing the pedosphere as an active carbon sphere can we fully unlock its potential in climate mitigation.<\/p>\n