Suess Effect

Considerable uncertainty remains over how increasing atmospheric CO2 and anthropogenic climate changes are affecting open‐ocean marine ecosystems from phytoplankton to top predators. Biological time series data are thus urgently needed for the world's oceans. Here, we use the carbon stable isotope composition of tuna to provide a first insight into the existence of global trends in complex ecosystem dynamics and changes in the oceanic carbon cycle. From 2000 to 2015, considerable declines in δ13C values of 0.8‰–2.5‰ were observed across three tuna species sampled globally, with more substantial changes in the Pacific Ocean compared to the Atlantic and Indian Oceans. Tuna recorded not only the Suess effect, that is, fossil fuel‐derived and isotopically light carbon being incorporated into marine ecosystems, but also recorded profound changes at the base of marine food webs. We suggest a global shift in phytoplankton community structure, for example, a reduction in 13C‐rich phytop...

Dendrochronology helps scientists gain a better understanding about the recent past. However, counting tree rings can only be applied to trees that have distinct rings, such as conifer trees and some hardwood trees. Liquid scintillation counting of radiocarbon of tree samples is one alternative to counting rings. Current standard preparation of wood samples for liquid scintillation counting involves a time-consuming and labor-intensive process of removing noncellulose components. This study attempted to compare the cellulose preparation technique with a charred wood technique, a less intensive preparation method. Both techniques were used to date samples Eucalyptus globulus from the Berkeley hills in California. Preliminary results of radiocarbon dating using accelerator mass spectrometry were unable to provide a reasonable age of the E. globulus samples. Machine error was not the cause of these results, thus an unknown environmental factor has caused radiocarbon dating unreliable f...

We present atmospheric radiocarbon concentrations in CO2 integrated samples taken between January 2019 and December 2021 in the Mexico City Metropolitan Area (MCMA) and explain the variations in terms of changes in emission sources associated with the COVID-19 lockdown restrictions imposed from March 2020. Δ14C values for samples collected during 2019 range between –44.15‰ and –13.17‰, with lower values during months with higher fossil fuels consumption and air stagnation, whereas higher values were found for periods with high number of fires around MCMA or wet months with higher contribution of heterotrophic respiration. For samples collected during 2020, Δ14C values range between –17.7‰ and 2.25‰, with an increasing trend immediately after the initial lockdown and higher values obtained for samples collected during lockdown phases 2 and 3 and the period of extremely high epidemic risk. This agrees with the 38% and 52% decrease in gasoline and diesel sales. Once essential activitie...

Considerable uncertainty remains over how increasing atmospheric CO2 and anthropogenic climate changes are affecting open‐ocean marine ecosystems from phytoplankton to top predators. Biological time series data are thus urgently needed for the world's oceans. Here, we use the carbon stable isotope composition of tuna to provide a first insight into the existence of global trends in complex ecosystem dynamics and changes in the oceanic carbon cycle. From 2000 to 2015, considerable declines in δ13C values of 0.8‰–2.5‰ were observed across three tuna species sampled globally, with more substantial changes in the Pacific Ocean compared to the Atlantic and Indian Oceans. Tuna recorded not only the Suess effect, that is, fossil fuel‐derived and isotopically light carbon being incorporated into marine ecosystems, but also recorded profound changes at the base of marine food webs. We suggest a global shift in phytoplankton community structure, for example, a reduction in 13C‐rich phytop...

We present atmospheric radiocarbon concentrations in CO2 integrated samples taken between January 2019 and December 2021 in the Mexico City Metropolitan Area (MCMA) and explain the variations in terms of changes in emission sources associated with the COVID-19 lockdown restrictions imposed from March 2020. Δ14C values for samples collected during 2019 range between –44.15‰ and –13.17‰, with lower values during months with higher fossil fuels consumption and air stagnation, whereas higher values were found for periods with high number of fires around MCMA or wet months with higher contribution of heterotrophic respiration. For samples collected during 2020, Δ14C values range between –17.7‰ and 2.25‰, with an increasing trend immediately after the initial lockdown and higher values obtained for samples collected during lockdown phases 2 and 3 and the period of extremely high epidemic risk. This agrees with the 38% and 52% decrease in gasoline and diesel sales. Once essential activitie...

Dendrochronological studies are limited in tropical regions because not many tree species form annual growth rings. This work reports an evaluation of the dendrochronological potential of tropical ash (Fraxinus uhdei) and its use as a bioindicator of fossil CO 2 concentration in urban areas by means of radiocarbon analysis on growth rings. We analyzed a cross-section of a tree that grew during the period 1932-2007 in San Luis Potosí, one of the most industrialized cities in Mexico. The  14 C values obtained follow the same variation pattern as the calibration curve of the Northern Hemisphere (NH) zone 2 (Hua and Barbetti 2004), with the peak centered in 1964, but they are lower by up to 124‰. The high correlation coefficient (r = 0.990, p < 0.001) between the variation patterns indicates that this species does form annual growth rings, and the lower values can be attributed to the 14 C dilution caused by fossil CO 2 emissions. The magnitude of the Suess effect varied between-6.9% and-0.5%, equivalent to fossil CO 2 concentrations ranging between 21.9 and 1.5 ppmv. The Suess effect and fossil CO 2 values have significant variations with no apparent monotone increasing trend, suggesting that the CO 2 emissions during the studied period have diverse sources. It is concluded that F. uhdei has potential for dendrochronological studies in tropical areas because its growth rings are formed annually and, furthermore, it can be used as a bioindicator of atmospheric 14 C variations and fossil CO 2 concentration in urban areas.

New delta13C data are presented from 10 coral skeletons collected from Florida and elsewhere in the Caribbean (Dominica, Dominican Republic, Puerto Rico, and Belize). These corals range from 96 to 200 years in age and were collected between 1976 and 2002. The change in the delta13C of the skeletons from these corals between 1900 and 1990 has been compared with 27 other published coral records from the Atlantic, Pacific, and Indian Oceans. The new data presented here make possible, for the first time, a global comparison of rates of change in the delta13C value of coral skeletons. Of these records, 64% show a statistically significant (p < 0.05) decrease in delta13C towards the modern day (23 out of 37). This decrease is attributable to the addition of anthropogenically derived CO2 (13C Suess effect) to the atmosphere. Between 1900 and 1990, the average rate of change of the delta13C in all the coral skeletons living under open oceanic conditions is approximately -0.010/00 yr-1. In the Atlantic Ocean the magnitude of the decrease since 1960,-0.019 yr-1 ±0.0150/00, is essentially the same as the decrease in the delta13C of atmospheric CO2 and the delta13C of the oceanic dissolved inorganic carbon (-0.023 to -0.0290/00 yr-1), while in the Pacific and Indian Oceans the rate is more variable and significantly reduced (-0.0070/00 yr-1 ±0.013). These data strongly support the notion that (i) the delta13C of the atmosphere controls ambient delta13C of the dissolved inorganic carbon which in turn is reflected in the coral skeletons, (ii) the rate of decline in the coral skeletons is higher in oceans with a greater anthropogenic CO2 inventory in the surface oceans, (iii) the rate of delta13C decline is accelerating. Superimposed on these secular variations are controls on the delta13C in the skeleton governed by growth rate, insolation, and local water masses.

1] New d 13 C data are presented from 10 coral skeletons collected from Florida and elsewhere in the Caribbean (Dominica, Dominican Republic, Puerto Rico, and Belize). These corals range from 96 to 200 years in age and were collected between 1976 and 2002. The change in the d 13 C of the skeletons from these corals between 1900 and 1990 has been compared with 27 other published coral records from the Atlantic, Pacific, and Indian Oceans. The new data presented here make possible, for the first time, a global comparison of rates of change in the d 13 C value of coral skeletons. Of these records, 64% show a statistically significant (p < 0.05) decrease in d 13 C towards the modern day (23 out of 37). This decrease is attributable to the addition of anthropogenically derived CO 2 ( 13 C Suess effect) to the atmosphere. Between 1900 and 1990, the average rate of change of the d 13 C in all the coral skeletons living under open oceanic conditions is approximately −0.01‰ yr −1 . In the Atlantic Ocean the magnitude of the decrease since 1960,−0.019 yr −1 ±0.015‰, is essentially the same as the decrease in the d 13 C of atmospheric CO 2 and the d 13 C of the oceanic dissolved inorganic carbon (−0.023 to −0.029‰ yr −1 ), while in the Pacific and Indian Oceans the rate is more variable and significantly reduced (−0.007‰ yr −1 ±0.013). These data strongly support the notion that (i) the d 13 C of the atmosphere controls ambient d 13 C of the dissolved inorganic carbon which in turn is reflected in the coral skeletons, (ii) the rate of decline in the coral skeletons is higher in oceans with a greater anthropogenic CO 2 inventory in the surface oceans, (iii) the rate of d 13 C decline is accelerating. Superimposed on these secular variations are controls on the d 13 C in the skeleton governed by growth rate, insolation, and local water masses. Citation: Swart, The 13 C Suess effect in scleractinian corals mirror changes in the anthropogenic CO 2 inventory of the surface oceans, Geophys.

1] New d 13 C data are presented from 10 coral skeletons collected from Florida and elsewhere in the Caribbean (Dominica, Dominican Republic, Puerto Rico, and Belize). These corals range from 96 to 200 years in age and were collected between 1976 and 2002. The change in the d 13 C of the skeletons from these corals between 1900 and 1990 has been compared with 27 other published coral records from the Atlantic, Pacific, and Indian Oceans. The new data presented here make possible, for the first time, a global comparison of rates of change in the d 13 C value of coral skeletons. Of these records, 64% show a statistically significant (p < 0.05) decrease in d 13 C towards the modern day (23 out of 37). This decrease is attributable to the addition of anthropogenically derived CO 2 ( 13 C Suess effect) to the atmosphere. Between 1900 and 1990, the average rate of change of the d 13 C in all the coral skeletons living under open oceanic conditions is approximately −0.01‰ yr −1 . In the Atlantic Ocean the magnitude of the decrease since 1960,−0.019 yr −1 ±0.015‰, is essentially the same as the decrease in the d 13 C of atmospheric CO 2 and the d 13 C of the oceanic dissolved inorganic carbon (−0.023 to −0.029‰ yr −1 ), while in the Pacific and Indian Oceans the rate is more variable and significantly reduced (−0.007‰ yr −1 ±0.013). These data strongly support the notion that (i) the d 13 C of the atmosphere controls ambient d 13 C of the dissolved inorganic carbon which in turn is reflected in the coral skeletons, (ii) the rate of decline in the coral skeletons is higher in oceans with a greater anthropogenic CO 2 inventory in the surface oceans, (iii) the rate of d 13 C decline is accelerating. Superimposed on these secular variations are controls on the d 13 C in the skeleton governed by growth rate, insolation, and local water masses. Citation: Swart, The 13 C Suess effect in scleractinian corals mirror changes in the anthropogenic CO 2 inventory of the surface oceans, Geophys.

1] New d 13 C data are presented from 10 coral skeletons collected from Florida and elsewhere in the Caribbean (Dominica, Dominican Republic, Puerto Rico, and Belize). These corals range from 96 to 200 years in age and were collected between 1976 and 2002. The change in the d 13 C of the skeletons from these corals between 1900 and 1990 has been compared with 27 other published coral records from the Atlantic, Pacific, and Indian Oceans. The new data presented here make possible, for the first time, a global comparison of rates of change in the d 13 C value of coral skeletons. Of these records, 64% show a statistically significant (p < 0.05) decrease in d 13 C towards the modern day (23 out of 37). This decrease is attributable to the addition of anthropogenically derived CO 2 ( 13 C Suess effect) to the atmosphere. Between 1900 and 1990, the average rate of change of the d 13 C in all the coral skeletons living under open oceanic conditions is approximately −0.01‰ yr −1 . In the Atlantic Ocean the magnitude of the decrease since 1960,−0.019 yr −1 ±0.015‰, is essentially the same as the decrease in the d 13 C of atmospheric CO 2 and the d 13 C of the oceanic dissolved inorganic carbon (−0.023 to −0.029‰ yr −1 ), while in the Pacific and Indian Oceans the rate is more variable and significantly reduced (−0.007‰ yr −1 ±0.013). These data strongly support the notion that (i) the d 13 C of the atmosphere controls ambient d 13 C of the dissolved inorganic carbon which in turn is reflected in the coral skeletons, (ii) the rate of decline in the coral skeletons is higher in oceans with a greater anthropogenic CO 2 inventory in the surface oceans, (iii) the rate of d 13 C decline is accelerating. Superimposed on these secular variations are controls on the d 13 C in the skeleton governed by growth rate, insolation, and local water masses. Citation: Swart, The 13 C Suess effect in scleractinian corals mirror changes in the anthropogenic CO 2 inventory of the surface oceans, Geophys.