Updated October Accessed January Rigby, M. Harth, J. Manning, P. Salameh, J. Kim, D. Ivy, L. Steele, V. Petrenko, J. Severinghaus, D. Baggenstos, and R. Nitrogen trifluoride global emissions estimated from updated atmospheric measurements.
USA 6 — Data updated December Accessed November Version 8. Updated November 20, Eggleston, J. Schmitt, C. Nehrbass-Ahles, T. Stocker, H. Fischer, S. Kipfstuhl, and J. Annual mean carbon dioxide concentrations for Mauna Loa, Hawaii. Updated September 23, Accessed December 29, Updated August 26, Updated December Krummel, and R. Commonwealth Scientific and Industrial Research Organisation.
Accessed January 20, Ciattaglia, A. Atmospheric carbon dioxide record from flask measurements at Lampedusa Island. In: Trends: A compendium of data on global change. Oak Ridge, TN: U. Department of Energy. Accessed September 14, Loulergue, L. Schilt, R. Spahni, V. Masson-Delmotte, T. Blunier, B. Lemieux, J. Barnola, D. Raynaud, T. Stocker, and J. Orbital and millennial-scale features of atmospheric CH 4 over the past , years. Nature — Steele, R.
Francey, and R. Accessed September 13, Updated July 24, With more atmospheric carbon dioxide available to convert to plant matter in photosynthesis, plants were able to grow more. This increased growth is referred to as carbon fertilization. Models predict that plants might grow anywhere from 12 to 76 percent more if atmospheric carbon dioxide is doubled, as long as nothing else, like water shortages, limits their growth.
Plants also need water, sunlight, and nutrients, especially nitrogen. There is a limit to how much carbon plants can take out of the atmosphere, and that limit varies from region to region.
So far, it appears that carbon dioxide fertilization increases plant growth until the plant reaches a limit in the amount of water or nitrogen available. Some of the changes in carbon absorption are the result of land use decisions. Agriculture has become much more intensive, so we can grow more food on less land.
In high and mid-latitudes, abandoned farmland is reverting to forest, and these forests store much more carbon, both in wood and soil, than crops would. In many places, we prevent plant carbon from entering the atmosphere by extinguishing wildfires.
This allows woody material which stores carbon to build up. All of these land use decisions are helping plants absorb human-released carbon in the Northern Hemisphere. Changes in land cover—forests converted to fields and fields converted to forests—have a corresponding effect on the carbon cycle. In some Northern Hemisphere countries, many farms were abandoned in the early 20th century and the land reverted to forest. As a result, carbon was drawn out of the atmosphere and stored in trees on land.
In the tropics, however, forests are being removed, often through fire, and this releases carbon dioxide. As of , deforestation accounted for about 12 percent of all human carbon dioxide emissions. The biggest changes in the land carbon cycle are likely to come because of climate change. Carbon dioxide increases temperatures, extending the growing season and increasing humidity. Both factors have led to some additional plant growth. However, warmer temperatures also stress plants.
With a longer, warmer growing season, plants need more water to survive. Scientists are already seeing evidence that plants in the Northern Hemisphere slow their growth in the summer because of warm temperatures and water shortages. Dry, water-stressed plants are also more susceptible to fire and insects when growing seasons become longer.
In the far north, where an increase in temperature has the greatest impact, the forests have already started to burn more, releasing carbon from the plants and the soil into the atmosphere.
Tropical forests may also be extremely susceptible to drying. With less water, tropical trees slow their growth and take up less carbon, or die and release their stored carbon to the atmosphere. This is of particular concern in the far north, where frozen soil—permafrost—is thawing. Feng, Z. Impact of elevated ozone concentration on growth, physiology and yield of wheat Triticum aestivum L.
Interactions between plant growth and soil nutrient cycling under elevated CO 2 : a meta-analysis. Global Change Biology 12 , Jablonski, L. Plant reproduction under elevated CO 2 conditions: a meta-analysis of reports on 79 crop and wild species. Keeling, R. Department of Energy, Leakey, A. Journal of Experimental Botany 60 , Loladze, I. Rising atmospheric CO 2 and human nutrition: toward globally imbalanced plant stoichiometry?
Long, S. Food for thought: Lower-than-expected crop yield stimulation with rising CO 2 concentrations. Marschner, H. Mineral Nutrition of Higher Plants , 2nd ed. London, UK: Academic Press, Morgan, P. How does elevated ozone impact soybean? A meta-analysis of photosynthesis, growth and yield. Plant, Cell and Environment 26 , Poorter, H. Plant growth and competition at elevated CO 2 : on winners, losers and functional groups.
Rogers, A. Will elevated carbon dioxide concentration amplify the benefits of nitrogen fixation in legumes? Plant Physiology , Stiling, P. How does elevated carbon dioxide CO 2 affect plant-herbivore interactions? A field experiment and meta-analysis of CO 2 -mediated changes on plant chemistry and herbivore performance. Global Change Biology 13 , Taub, D. Effects of elevated CO 2 on the protein concentration of food crops: a meta-analysis.
Why are nitrogen concentrations in plant tissues lower under elevated CO 2? A critical examination of the hypotheses. Journal of Integrative Plant Biology 50 , Vingarzan, R. A review of surface ozone background levels and trends. Atmospheric Environment 38 , Ziska, L. Rising atmospheric carbon dioxide and plant biology: the overlooked paradigm.
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Nature Education Knowledge 3 10 Photosynthetic assimilation of CO2 is central to the metabolism of plants. As atmospheric concentrations of CO2 rise, how will this affect the plants we depend on? Aa Aa Aa. The effects of elevated CO 2 on plants can vary depending on other environmental factors. While elevated CO 2 makes carbon more available, plants also require other resources including minerals obtained from the soil.
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