The evolution of the Earth's climate over the twenty-first century depends on the rate at which anthropogenic carbon dioxide emissions are removed from the atmosphere by the ocean and land carbon cycles. Coupled climate-carbon cycle models suggest that global warming will act to limit the land-carbon sink, but these first generation models neglected the impacts of changing atmospheric chemistry. Emissions associated with fossil fuel and biomass burning have acted to approximately double the global mean tropospheric ozone concentration, and further increases are expected over the twenty-first century. Tropospheric ozone is known to damage plants, reducing plant primary productivity and crop yields, yet increasing atmospheric carbon dioxide concentrations are thought to stimulate plant primary productivity. Increased carbon dioxide and ozone levels can both lead to stomatal closure, which reduces the uptake of either gas, and in turn limits the damaging effect of ozone and the carbon dioxide fertilization of photosynthesis. Here we estimate the impact of projected changes in ozone levels on the land-carbon sink, using a global land carbon cycle model modified to include the effect of ozone deposition on photosynthesis and to account for interactions between ozone and carbon dioxide through stomatal closure. For a range of sensitivity parameters based on manipulative field experiments, we find a significant suppression of the global land-carbon sink as increases in ozone concentrations affect plant productivity. In consequence, more carbon dioxide accumulates in the atmosphere. We suggest that the resulting indirect radiative forcing by ozone effects on plants could contribute more to global warming than the direct radiative forcing due to tropospheric ozone increases.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1038/nature06059 | DOI Listing |
Sci Rep
January 2025
College of Ecology and Environment, Hainan University, Haikou, 570228, China.
Agroforestry systems are known to enhance soil health and climate resilience, but their impact on greenhouse gas (GHG) emissions in rubber-based agroforestry systems across diverse configurations is not fully understood. Here, six representative rubber-based agroforestry systems (encompassing rubber trees intercropped with arboreal, shrub, and herbaceous species) were selected based on a preliminary investigation, including Hevea brasiliensis intercropping with Alpinia oxyphylla (AOM), Alpinia katsumadai (AKH), Coffea arabica (CAA), Theobroma cacao (TCA), Cinnamomum cassia (CCA), and Pandanus amaryllifolius (PAR), and a rubber monoculture as control (RM). Soil physicochemical properties, enzyme activities, and GHG emission characteristics were determined at 0-20 cm soil depth.
View Article and Find Full Text PDFVet Anaesth Analg
January 2025
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
Objective: To determine the effects of rapid (1 minute) and slow (10 minutes) intravenous (IV) injection of sodium penicillin on arterial blood pressure in anesthetized horses.
Study Design: Prospective randomized clinical trial.
Animals: A group of 29 client-owned horses of various breeds, 1-20 years old, with body masses of 360-710 kg.
Br J Anaesth
January 2025
Department of Anaesthesia, Monash Medical Centre, Melbourne, VIC, Australia.
Braz J Anesthesiol
January 2025
Zhongshan City People's Hospital, Department of Anesthesiology, Zhongshan, China.
Background: Extracorporeal Cardiopulmonary Resuscitation (ECPR) is an effective intervention for restoring adequate circulatory perfusion after cardiac arrest. Ensuring high-quality Cardiopulmonary Resuscitation (CPR) before initiating Extracorporeal Membrane Oxygenation (ECMO) is critical to mitigate tissue hypoxia and ischemia. This study aimed to evaluate the effect of End-Tidal Carbon Dioxide (ETCO) Goal-Directed CPR (GDCPR) on neurological function before ECMO using a retrospective case-control analysis.
View Article and Find Full Text PDFEnviron Res
January 2025
Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
Background: Air pollution has been linked to respiratory diseases, while the effects of greenness remain inconclusive.
Objective: We investigated the associations between exposure to particulate matter (PM and PM), black carbon (BC), nitrogen dioxide (NO), ozone (O), and greenness (normalized difference vegetation index, NDVI) with respiratory emergency room visits and hospitalizations across seven Northern European centers in the European Community Respiratory Health Survey (ECRHS) study.
Methods: We used modified mixed-effects Poisson regression to analyze associations of exposure in 1990, 2000 and mean exposure 1990-2000 with respiratory outcomes recorded duing ECRHS phases II and III.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!