Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach
We investigated changes in atmospheric CO 2 concentration (hereafter [CO 2 ]) over the period AD 1700—2002 as reconstructed using the inverse relationship between stomatal frequencies (SF) of Betula nana leaves from northern Europe and [CO 2 ]. The predictive ability of SF-inference models was asses...
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crsagepubl:10.1177/0959683609105300 2024-04-07T07:51:31+00:00 Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach Finsinger, W. Wagner-Cremer, F. 2009 http://dx.doi.org/10.1177/0959683609105300 http://journals.sagepub.com/doi/pdf/10.1177/0959683609105300 en eng SAGE Publications http://journals.sagepub.com/page/policies/text-and-data-mining-license The Holocene volume 19, issue 5, page 757-764 ISSN 0959-6836 1477-0911 Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change journal-article 2009 crsagepubl https://doi.org/10.1177/0959683609105300 2024-03-08T03:17:58Z We investigated changes in atmospheric CO 2 concentration (hereafter [CO 2 ]) over the period AD 1700—2002 as reconstructed using the inverse relationship between stomatal frequencies (SF) of Betula nana leaves from northern Europe and [CO 2 ]. The predictive ability of SF-inference models was assessed using a method of independent validation that involves two steps: (1) a training set of leaves grown between AD 1843 and 2002 was used to generate inference models; (2) the models were then applied to a fossil SF record of leaves grown between AD 1700 and 2002 that was split into two parts, a validation period (after AD 1850) and a reconstruction period (AD 1700—1850). Although our inference models had uncertainties comparable with other SF-inference models (root mean square error (RMSE) = c. 18—19 ppmv), uncertainties arising from the independent validation were larger (RMSE = c. 31—34 ppmv). Smoothed SF-inferred [CO 2 ] values after AD 1850 corresponded better to the industrial [CO 2 ] increase observed from instrumental records and from high-resolution ice cores, corroborating the accuracy of the reconstruction method in capturing a long-term (decadal- to centennial-scale) signal. This also indicates that in our record higher-frequency signals (eg, [CO 2 ] maxima around AD 1750) are potentially less reliable. In an attempt to estimate the maximum reconstruction uncertainty (± 67 ppmv), we considered (i) the RMSE of the validation (validation error) and (ii) the maximum difference between reconstructions obtained with different inference models during the validation period (method error). We suggest that reconstruction uncertainties may be reduced by reducing the uncertainty of our inference models, with a subfossil record characterized by lower variability in the SF time series over the validation period, and by smoothing the reconstruction. This study shows that independent validation is an important step to assess the precision and accuracy of quantitative proxy-based reconstructions. Article in Journal/Newspaper Betula nana SAGE Publications The Holocene 19 5 757 764 |
institution |
Open Polar |
collection |
SAGE Publications |
op_collection_id |
crsagepubl |
language |
English |
topic |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
spellingShingle |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change Finsinger, W. Wagner-Cremer, F. Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach |
topic_facet |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
description |
We investigated changes in atmospheric CO 2 concentration (hereafter [CO 2 ]) over the period AD 1700—2002 as reconstructed using the inverse relationship between stomatal frequencies (SF) of Betula nana leaves from northern Europe and [CO 2 ]. The predictive ability of SF-inference models was assessed using a method of independent validation that involves two steps: (1) a training set of leaves grown between AD 1843 and 2002 was used to generate inference models; (2) the models were then applied to a fossil SF record of leaves grown between AD 1700 and 2002 that was split into two parts, a validation period (after AD 1850) and a reconstruction period (AD 1700—1850). Although our inference models had uncertainties comparable with other SF-inference models (root mean square error (RMSE) = c. 18—19 ppmv), uncertainties arising from the independent validation were larger (RMSE = c. 31—34 ppmv). Smoothed SF-inferred [CO 2 ] values after AD 1850 corresponded better to the industrial [CO 2 ] increase observed from instrumental records and from high-resolution ice cores, corroborating the accuracy of the reconstruction method in capturing a long-term (decadal- to centennial-scale) signal. This also indicates that in our record higher-frequency signals (eg, [CO 2 ] maxima around AD 1750) are potentially less reliable. In an attempt to estimate the maximum reconstruction uncertainty (± 67 ppmv), we considered (i) the RMSE of the validation (validation error) and (ii) the maximum difference between reconstructions obtained with different inference models during the validation period (method error). We suggest that reconstruction uncertainties may be reduced by reducing the uncertainty of our inference models, with a subfossil record characterized by lower variability in the SF time series over the validation period, and by smoothing the reconstruction. This study shows that independent validation is an important step to assess the precision and accuracy of quantitative proxy-based reconstructions. |
format |
Article in Journal/Newspaper |
author |
Finsinger, W. Wagner-Cremer, F. |
author_facet |
Finsinger, W. Wagner-Cremer, F. |
author_sort |
Finsinger, W. |
title |
Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach |
title_short |
Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach |
title_full |
Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach |
title_fullStr |
Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach |
title_full_unstemmed |
Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach |
title_sort |
stomatal-based inference models for reconstruction of atmospheric co2 concentration: a method assessment using a calibration and validation approach |
publisher |
SAGE Publications |
publishDate |
2009 |
url |
http://dx.doi.org/10.1177/0959683609105300 http://journals.sagepub.com/doi/pdf/10.1177/0959683609105300 |
genre |
Betula nana |
genre_facet |
Betula nana |
op_source |
The Holocene volume 19, issue 5, page 757-764 ISSN 0959-6836 1477-0911 |
op_rights |
http://journals.sagepub.com/page/policies/text-and-data-mining-license |
op_doi |
https://doi.org/10.1177/0959683609105300 |
container_title |
The Holocene |
container_volume |
19 |
container_issue |
5 |
container_start_page |
757 |
op_container_end_page |
764 |
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1795666507772985344 |