toine74 a écrit:La conclusion de l'article d'origine8. Conclusion
We estimate that 55 million indigenous people died following the European conquest of the Americas beginning in 1492. This led to the abandonment and secondary succession of 56 million hectares of land. We calculate that this led to an additional 7.4 Pg C being removed from the atmosphere and stored on the land surface in the 1500s. This was a change from the 1400s of 9.9 Pg C (5 ppm CO2). Including feedback processes this contributed between 47% and 67% of the 15–22 Pg C (7–10 ppm CO2) decline in atmospheric CO2 between 1520 CE and 1610 CE seen in Antarctic ice core records. These changes show that the Great Dying of the Indigenous Peoples of the Americas is necessary for a parsimonious explanation of the anomalous decrease in atmospheric CO2 at that time and the resulting decline in global surface air temperatures. These changes show that human actions had global impacts on the Earth system in the centuries prior to the Industrial Revolution. Our results also show that this aspect of the Columbian Exchange – the globalisation of diseases – had global impacts on the Earth system, key evidence in the calls for the drop in atmospheric CO2 at 1610 CE to mark the onset of the Anthropocene epoch (Lewis and Maslin, 2015, 2018). We conclude that the Great Dying of the Indigenous Peoples of the Americas led to the abandonment of enough cleared land in the Americas that the resulting terrestrial carbon uptake had a detectable impact on both atmospheric CO2 and global surface air temperatures in the two centuries prior to the Industrial Revolution.
= l'info c'est qu'ils ont "trouvé" "déduit" "calculé" d'où venait la diminution de CO2 mesurée dans des carottes de glace antarctiques (le massacre des populations améridiennes) et ils sont arrivés à la conclusion qu'on pouvait donc voir l'impact de l'homme sur l'atmosphère avant la révolution industrielle (et l'explosion des émissions de CO2). C'est tout (ce qui est déjà beaucoup en terme de travail d'analyse).
Ca me parait juste en timing. On découvre l'Amérique en 1492. Faut déjà le temps de tuer tout le monde. Mettons 8 ans. Faut après que les plantes poussent et paf, 1709, gros hyver en Picardie. C'est serré, serré. Surtout que les cultures absorbaient aussi du CO².
Je suis mitigé.
Je mitige.