#Analyse : a-t-on observé un effondrement des #puits_de_carbone_terrestres en #2023 ?
▻https://bonpote.com/analyse-a-t-on-observe-un-effondrement-des-puits-de-carbone-terrestres-en-2
“Un #effondrement des puits de carbone terrestres en 2023”.
"Je ne dis pas cela méchamment, mais j’espère vraiment que ce document est tout simplement erroné. Une détérioration rapide du puits de carbone terrestre dans un avenir proche pourrait avoir des conséquences vraiment terribles." Voici ce qu’a déclaré Robert Rohde, directeur scientifique au Berkeley Earth, le jour de la sortie de l’étude.
En effet, il y a de quoi être inquiet. Si cela se confirmait, ce serait de très loin la pire nouvelle climatique depuis plusieurs années. C’est l’été, il y existe semble-t-il une “trêve politique” pendant les Jeux Olympiques 2024, mais s’il y a une chose qui ne prend pas de vacances, c’est bien le #changement_climatique.
#Incendies, #sécheresses… et un possible emballement du climat si un tel déclin persistait. Rien que ça. Dans cet article, nous reviendrons sur ce que sont les puits de carbone, ce que nous dit l’étude et les conséquences que cela pourrait avoir.
#Trees and #land absorbed almost no CO2 last year. Is nature’s carbon sink failing? | Oceans | #The_Guardian
▻https://www.theguardian.com/environment/2024/oct/14/nature-carbon-sink-collapse-global-heating-models-emissions-targets-evi
Only one major tropical rainforest – the #Congo_basin – remains a strong #carbon_sink that removes more than it releases into the atmosphere. Exacerbated by #El_Niño #weather patterns, deforestation and global heating, the Amazon basin is experiencing a record-breaking drought, with rivers at an all-time low. Expansion of #agriculture has turned #tropical_rainforests in south-east Asia into a net source of #emissions in recent years.
Emissions from soil – which is the second-largest active carbon store after the oceans – are expected to increase by as much as 40% by the end of the century if they continue at the current rate, as soils become drier and microbes break them down faster.
Tim Lenton, professor of #climate_change and #Earth_system_science at Exeter University, says: “We are seeing in the biosphere some surprising responses that are not what got predicted, just as we are in the #climate.
“You have to question: to what degree can we rely on them as carbon sinks or carbon stores?” he says.
A paper published in July found that while the total amount of carbon absorbed by forests between 1990 and 2019 was steady, it varied substantially by region. The boreal forests – home to about a third of all carbon found on land, which stretch across Russia, Scandinavia, Canada and Alaska – have seen a sharp fall in the amount of carbon they absorb, down more than a third due to climate crisis-related beetle outbreaks, fire and clearing for timber.