Eawag: Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland.
Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Agronomía, Universidad de Buenos Aires en las afiliations, Buenos Aires, Argentina.
Photochem Photobiol Sci. 2019 Mar 1;18(3):747-774. doi: 10.1039/c8pp90063a. Epub 2019 Feb 27.
Global change influences biogeochemical cycles within and between environmental compartments (i.e., the cryosphere, terrestrial and aquatic ecosystems, and the atmosphere). A major effect of global change on carbon cycling is altered exposure of natural organic matter (NOM) to solar radiation, particularly solar UV radiation. In terrestrial and aquatic ecosystems, NOM is degraded by UV and visible radiation, resulting in the emission of carbon dioxide (CO) and carbon monoxide, as well as a range of products that can be more easily degraded by microbes (photofacilitation). On land, droughts and land-use change can reduce plant cover causing an increase in exposure of plant litter to solar radiation. The altered transport of soil organic matter from terrestrial to aquatic ecosystems also can enhance exposure of NOM to solar radiation. An increase in emission of CO from terrestrial and aquatic ecosystems due to the effects of global warming, such as droughts and thawing of permafrost soils, fuels a positive feedback on global warming. This is also the case for greenhouse gases other than CO, including methane and nitrous oxide, that are emitted from terrestrial and aquatic ecosystems. These trace gases also have indirect or direct impacts on stratospheric ozone concentrations. The interactive effects of UV radiation and climate change greatly alter the fate of synthetic and biological contaminants. Contaminants are degraded or inactivated by direct and indirect photochemical reactions. The balance between direct and indirect photodegradation or photoinactivation of contaminants is likely to change with future changes in stratospheric ozone, and with changes in runoff of coloured dissolved organic matter due to climate and land-use changes.
全球变化影响着环境介质（即冰冻圈、陆地和水生生态系统以及大气）内部和之间的生物地球化学循环。全球变化对碳循环的主要影响是改变了自然有机物质（NOM）对太阳辐射的暴露，特别是太阳紫外线辐射。在陆地和水生生态系统中，NOM 会被紫外线和可见光辐射降解，导致二氧化碳（CO）和一氧化碳的排放，以及一系列更容易被微生物降解的产物（光促进作用）。在陆地上，干旱和土地利用变化会减少植被覆盖，导致植物凋落物更多地暴露在太阳辐射下。土壤有机质从陆地向水生生态系统的改变运输也会增加 NOM 对太阳辐射的暴露。由于全球变暖的影响，如干旱和永久冻土的融化，陆地和水生生态系统中 CO 的排放增加，对全球变暖产生了正反馈。除 CO 以外的温室气体，包括来自陆地和水生生态系统的甲烷和氧化亚氮，也是如此。这些痕量气体也对平流层臭氧浓度有间接或直接的影响。紫外线辐射和气候变化的相互作用极大地改变了合成和生物污染物的命运。污染物通过直接和间接光化学反应降解或失活。未来平流层臭氧的变化以及由于气候和土地利用变化导致有色溶解有机物径流量的变化，可能会改变污染物直接和间接光降解或光失活的平衡。
