| 1. |
- Barros, Nathan, et al.
(författare)
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Carbon emission from hydroelectric reservoirs linked to reservoir age and latitude
- 2011
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Ingår i: Nature Geoscience. - : Nature Publishing Group. - 1752-0894 .- 1752-0908. ; 4:9, s. 593-596
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Tidskriftsartikel (refereegranskat)abstract
- Hydroelectric reservoirs cover an area of 3.4 x 10(5) km(2) and comprise about 20% of all reservoirs. In addition, they contain large stores of formerly terrestrial organic carbon. Significant amounts of greenhouse gases are emitted(2), especially in the early years following reservoir creation, but the global extent of these emissions is poorly known. Previous estimates of emissions from all types of reservoir indicate that these human-made systems emit 321 Tg of carbon per year (ref. 4). Here we assess the emissions of carbon dioxide and methane from hydroelectric reservoirs, on the basis of data from 85 globally distributed hydroelectric reservoirs that account for 20% of the global area of these systems. We relate the emissions to reservoir age, location biome, morphometric features and chemical status. We estimate that hydroelectric reservoirs emit about 48 Tg C as CO(2) and 3 Tg C as CH(4), corresponding to 4% of global carbon emissions from inland waters. Our estimates are smaller than previous estimates on the basis of more limited data. Carbon emissions are correlated to reservoir age and latitude, with the highest emission rates from the tropical Amazon region. We conclude that future emissions will be highly dependent on the geographic location of new hydroelectric reservoirs.
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| 2. |
- Battin, Tom J., et al.
(författare)
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The boundless carbon cycle
- 2009
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Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 2:9, s. 598-600
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Catalan, Nuria, et al.
(författare)
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Organic carbon decomposition rates controlled by water retention time across inland waters
- 2016
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Ingår i: Nature Geoscience. - 1752-0894 .- 1752-0908. ; 9:7, s. 501-504
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Tidskriftsartikel (refereegranskat)abstract
- The loss of organic carbon during passage through the continuum of inland waters from soils to the sea is a critical component of the global carbon cycle(1-3). Yet, the amount of organic carbon mineralized and released to the atmosphere during its transport remains an open question(2,4-6), hampered by the absence of a common predictor of organic carbon decay rates(1,7). Here we analyse a compilation of existing field and laboratory measurements of organic carbon decay rates and water residence times across a wide range of aquatic ecosystems and climates. We find a negative relationship between the rate of organic carbon decay and water retention time across systems, entailing a decrease in organic carbon reactivity along the continuum of inland waters. We find that the half-life of organic carbon is short in inland waters (2.5 +/- 4.7 yr) compared to terrestrial soils and marine ecosystems, highlighting that freshwaters are hotspots of organic carbon degradation. Finally, we evaluate the response of organic carbon decay rates to projected changes in runoff(8). We calculate that regions projected to become drier or wetter as the global climate warms will experience changes in organic carbon decay rates of up to about 10%, which illustrates the influence of hydrological variability on the inland waters carbon cycle.
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| 4. |
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| 5. |
- Mendonca, Raquel, 1983-, et al.
(författare)
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Hydroelectric carbon sequestration
- 2012
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Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 5, s. 838-840
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Tranvik, Lars
(författare)
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New light on black carbon
- 2018
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Ingår i: Nature Geoscience. - : Nature Publishing Group. - 1752-0894 .- 1752-0908. ; 11:8, s. 547-548
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Much of the carbon in rivers originates from wildfires and is ultimately buried in the oceanic carbon sink, suggest measurements from 18 rivers globally. Rivers transport almost a gigaton of carbon to the oceans every year.
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| 7. |
- Weyhenmeyer, Gesa, et al.
(författare)
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Significant fraction of CO2 emissions from boreal lakes derived from hydrologic inorganic carbon inputs
- 2015
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Ingår i: Nature Geoscience. - 1752-0894 .- 1752-0908. ; 8:12, s. 933-936
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Tidskriftsartikel (refereegranskat)abstract
- Annual CO2 emissions from lakes and other inland waters into the atmosphere are estimated to almost entirely compensate the total annual carbon uptake by oceans. CO2 supersaturation in lakes, which results in CO2 emissions, is frequently attributed to CO2 produced within the lake. However, lateral inorganic carbon flux through watersheds can also be sizeable. Here we calculated lake surface water CO2 concentrations and emissions using lake pH, alkalinity and temperature from a compilation of data from 5,118 boreal lakes. Autumn surface water CO2 concentrations and CO2 emissions from the 5,118 lakes co-varied with lake internal autumn CO2 production. However, using a mass balance approach we found that CO2 emission in the majority of lakes was sustained by inorganic carbon loading from the catchment rather than by internal CO2 production. Small lakes with high dissolved organic carbon and phosphorus concentrations, shorter retention times and longer ice-free seasons had the highest CO2 concentrations. CO2 emissions from these small lakes was twice that of comparable lakes in colder regions, and similar to emissions from subtropical and tropical lakes. We conclude that changes in land use and climate that increase dissolved inorganic carbon may cause emission levels from boreal lakes to approach those of lakes in warmer regions.
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