Scharpenseel, H.-W., Becker-Heidmann, P. (1990): Overview of the Greenhouse Effect, Global Change Syndrom, General Outlook. – In: Scharpenseel, H. W., Schomaker, M., Ayoub, A. (Hg.): Soils on a warmer earth:, S. 1–14. Developments in soil science 20. Elsevier, Amsterdam, New York
Accumulation of cosmic dust and planetesimals was most likely the mechanism that created our planet. Due to dominance of hydrogen, the extruded gases produced a primordial reducing atmosphere, enriched with methane and ammonia. Then, after a slow start, continued oxidation with oxygen, released from photolysis of water, and the later development of life from photosynthesis caused the atmosphere to become dominated by CO2, water vapor and N. The two former components were able to trap IR radiation and to produce a warming greenhouse effect of 33°C. shifting the surface temperature to +15°C.
Oxygen from photosynthesis (at present yearly ca 330 bil t from terrestrial photosynthesis) was used over at least 2 billion years, for sustaining respiration of the various facets of life and for iron oxidation in marine and terrestrial sediments. During the last billion years oxygen began to enrich in the atmosphere, parallel to reducing CO2 concentration, due to its consumption by photosynthesis, chemical weathering and the carbonate precipitating pumping effect of the oceans. CO2 replenishment occurs via volcanism and release from subduction zones.
The faster biochemical cycle of smaller pool size (organic matter production, respiration, humification, kerogene formation, and biotic-abiotic-photochemical organic matter turnover) and over longer geological periods especially the slow but very large geochemical cycle (exchange of carbon between atmosphere, ocean, biosphere, and sediments), are decisive for CO2 concentration and its contribution to temperature. Some features of the biochemical cycle against the background of climate changes, including those due to Pangaea / Gondwana shifting, are discussed.
Life is on a carbon trip. Wasteful consumption of fossil C based fuel, due to rising living standard and population explosion in conjunction with increasing release of greenhouse active (radiatively active) gases – which are fingerprinted – threatens to exert climate changes detrimental to our life conditions and civilization.
Arguments to characterize the situation are assessed, also those expressing potential advantages of increasing CO2 concentration for crop yields and expansion of the farmland area, doomed to shrinking at he present level of population explosion.
The need for a change from the carbon trip to a mixed carbon – hydrogen trip is evident.