Adaptivity is threatened by global warming and deforestation.
The Earth’s climate system is highly complex, with its key components—the ocean, atmosphere, and vegetation—closely interconnected. Changes in one element can trigger widespread effects throughout the system. While these components exhibit some resilience and can absorb certain fluctuations, climate and Earth-system research suggest the existence of critical tipping points. If these thresholds are crossed, the climate system could shift rapidly into a different state.
Tipping points in the climate system are believed to interact, potentially triggering cascading effects. Two significant global tipping points are the Amazon rainforest and the Atlantic Meridional Overturning Circulation (AMOC). Continued global warming could substantially weaken the AMOC, disrupting the oceanic conveyor belt that transports warm water to northern latitudes. This would alter temperature distribution across the Atlantic, which, in turn, could impact the Amazon region. Changes in Atlantic temperatures would influence the atmospheric water cycle, leading to shifts in precipitation patterns that could further destabilize the rainforest ecosystem.
Analysis of Residual Pollen and Carbon
Exactly how the AMOC and the Amazon are interconnected as systems, and how marine circulation affects the Amazon region, have not yet been extensively researched. A group of researchers led by Dr. Thomas Akabane and Prof. Dr. Christiano Chiessi from the University of São Paulo has now analyzed changes in the vegetation of the Amazon region. With their international team, they have analyzed pollen and carbon residues representing the past 25,000 years from a marine sediment core taken from the mouth of the Amazon River.
This analysis provides the team with a detailed glimpse into the past of one of the most species-rich ecosystems on Earth. The data show how the vegetation, along with wet and dry periods, has changed during the climate events of the last ice age, called Heinrich Events, when the AMOC was drastically weakened. The researchers found, in particular, a dramatic decline in rainforest vegetation in the northern part of the Amazon region.
Close Connection Between Atlantic Circulation and the Amazon Ecosystem
“The study is the result of a long-term German-Brazilian cooperative project, which began in 2012 with a joint expedition of the Research Vessel MARIA S. MERIAN in the estuarine area of the Amazon. Our data show that the Amazon ecosystem was able to adapt in the past to changes in the patterns of precipitation that resulted from weakened Atlantic circulation. But a weakening of the AMOC in the future occurring simultaneously with an increase in deforestation could threaten the stability of this important global system,” says Dr. Stefan Mulitza of MARUM.
Further studies employing climate and vegetation models indicate that a weakening of the AMOC under present-day conditions would have an effect on Amazon vegetation similar to that which it had during the past ice age. “The models have shown us that the AMOC need not completely collapse in order to have an effect on the rainforest. The northern areas of the Amazon region are massively impacted under mere moderate changes in the AMOC,” explains Dr. Matthias Prange of MARUM.
The results illustrate how complex the global system is. “Driving processes at high latitudes, like the melting of Greenland ice, can have a substantial effect on the tropics. Such long-distance influences often have severe regional effects, very often for people who are only minimally responsible for causing climate change,” adds Prof. Dr. Gerrit Lohmann of AWI.
Reference: “Weaker Atlantic overturning circulation increases the vulnerability of northern Amazon forests” by T. K. Akabane, C. M. Chiessi, M. Hirota, I. Bouimetarhan, M. Prange, S. Mulitza, D. J. Bertassoli Jr, C. Häggi, A. Staal, G. Lohmann, N. Boers, A. L. Daniau, R. S. Oliveira, M. C. Campos, X. Shi and P. E. De Oliveira, 1 November 2024, Nature Geoscience.
DOI: 10.1038/s41561-024-01578-z
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10 Comments
Allways this cherry picking. this pannick making. Real science mentions all points of view, all observations in contrast to hypothesis and calculations.
Pongsiri, Nitinun, Rhysa McNeil, Rattikan Saelim, Benjamin Atta Owusu, and S. O. M. P. O. R. N. CHUAI-AREE (2024). Spatial and temporal patterns of land surface temperature in Greenland from 2000-2019. MAUSAM – Quarterly Journal of Meteorology, Hydrology and Geophysics 75(2): 543-550.
https://www.nature.com/articles/s41467-024-48886-x:Article
Open access
Published: 25 May 2024
Early aerial expedition photos reveal 85 years of glacier growth and stability in East Antarctica
Mads Dømgaard, Anders Schomacker, Elisabeth Isaksson, Romain Millan, Flora Huiban, Amaury Dehecq, Amanda Fleischer, Geir Moholdt, Jonas K. Andersen & Anders A. Bjørk
Nature Communications volume 15, Article number: 4466 (2024)
https://journals.ametsoc.org/view/journals/bams/104/6/BAMS-D-22-0153.1.xml
Significant West Antarctic Cooling in the Past Two Decades Driven by Tropical Pacific Forcing
Xueying Zhang
And so on.
, Shugui Hou
, and Petra Heil
“Continued global warming COULD substantially weaken the AMOC, disrupting the oceanic conveyor belt that transports warm water to northern latitudes.”
I’m so tired of these unsupported, speculative ‘coulds.’ A recent article here demonstrates that there is no empirical evidence to support the speculation: https://scitechdaily.com/climate-puzzle-scientists-uncover-mysterious-halt-in-the-atlantic-conveyor-belt-slowdown/
Get back to us when you are willing to assign and defend a numeric probability, along with a margin of error, to the subjective opinion.
“Could” indicates caution. “I could die” gets me to the emergency room, instead of the morgue. Of course, “could” is inconvenient for you – given that your prolific postings indicate that your job is to sow as much confusion as possible about climate change.
I have no job. I’m retired. That means I have the luxury of the time to react to misinformation. What motivates me is that I dislike unsupported claims and cherry-picked ‘facts’ because I revere science. I have very high standards for science, unlike individuals who are motivated by tenure goals and salary, or those who know too little to read claims critically.
If you think that anything I have written is false, all you have to do call it to everyone’s attention and cite why you disagree with it.
The reason that the Scientific Method includes publication is so that peers can review the data for reasonableness, and offer facts that were omitted, and question the logic of the conclusions. What commonly passes for “peer review” is actually a gate-keeping function so that the profitable journal publishing industry doesn’t have its reputation tarnished by the equivalent of ‘perpetual motion machines.’ There is nothing sacrosanct about having research published in a ‘peer reviewed’ journal when roughly half of all medical research cannot be replicated. Peer review merely reduces the probability of the publisher being embarrassed by fraudulent work, although there are a couple of instances where something that was purposely wrong, to test the system, got through the peer review.
An example of fraudulent behavior is someone who makes a claim for which it is obviously impossible for them to support their assertion, such as your claim that I’m employed to sow confusion. Why you do it is known only by you. Unlike you, I won’t claim to know why you do it.
I have news for you. You WILL die. It is just a matter of when.
When I drive my car on the road, I could be killed by an errant truck driver. So I take care.
“Could” is a useful word used among other things to predict a future, even if that future seems unlikely. The concept is to express possible risk inherent in driving a car and I don’t give a tinker’s cuss about the likelihood and statistics of encountering that errant truck. Assuming global warming, whatever the cause, gets to about 3deg C above whatever might be considered the average global temperature in 1890 then the social impact of that will make Israel’s criminal activities in Gaza, Lebanon, the Occupied Territories and Syria look like kindergarden play.
“Could” expresses an idea that can be used to stimulate further testing of that idea. That is science.
“Could” is a word that should be reserved for lawyers and people who have no way of determining what the probability for an event is. It is often said that the language of science is mathematics. “Could” only expresses a possibility, not a probability. That is, “could” implies that there is nothing preventing an event from happening. However, it says nothing about the probability other than the probability being finite. It becomes science when measurements are taken and analyzed. Prior to that, it is just subjective speculation, which is the realm of science fiction.
You never did respond to my question to you about what precautions you were taking to prepare for the low-probability event of an asteroid strike. Are you just going to drive more carefully?
BS misdirection.
We are not personally inviting the asteroid to come and hit earth. We are, on the other hand, causing global warming. We have more control on one over the other.
That said, yes, NASA is indeed working on methods to guide problematic asteroids away from us. Some people work on solutions; you seem intent on causing confusion.
While on the subject of questions- let me ask you one. Do you think average global temperatures have increased over the last 50 years?
I will answer your direct question first. Yes, I think that there has been some warming. One of the best lines of evidence is that the guide for planting has changed, taking into account Fall frosts coming later, and Spring frosts ending earlier. However, even the EPA website shows that heat waves were more frequent and severe in the 1930s than in recent years. An analysis of the variance in US Tmax data does not support the claim of heat waves increasing: https://wattsupwiththat.com/2019/09/06/the-gestalt-of-heat-waves/
However, I do not think that anthropogenic CO2 is the primary driver for the warming. It is undoubtedly part of a feedback loop, but all the evidence I have looked at leads me to believe that the seasonal variation is driven by biology and is much larger than the approximately constant 4% annual flux of anthro’ CO2. The situation is far too complex to describe here in detail. But something to think about is that the CO2 added to the atmosphere from the various sources should be in proportion to the partial pressure of the sources, which means that anthro’ CO2 flux into the atmosphere is only about 4% of the total seasonal flux. That explains why a 10% decline of CO2 in 2020 during the COVID pandemic cannot be seen in either the temperatures or total CO2 concentration.
You said, “you seem intent on causing confusion.” No. My concern is that if solutions to reduce warming fall in the category of making sacrifices to the gods, there is little chance of finding the right solution. My intent is to dispel the confusion by pointing out the errors in logic and cherry picking of data to support the wrong cause of warming. That is even more the case in the recent emphasis on reducing fugitive methane emissions: https://wattsupwiththat.com/2023/03/06/the-misguided-crusade-to-reduce-anthropogenic-methane-emissions/
You further said, “We are, on the other hand, causing global warming.” I have little doubt that you believe that. Although, I do doubt that you can make a compelling argument to support your belief. The two most compelling arguments involve the change in isotopic composition of atmospheric CO2 and the mass-balance position. Both are incompletely addressed in the presentations I have read.
The poster you are responding to is a full time climate apologist, likely employed by some oil company or the like. He doesn’t miss a single opportunity to sow doubt. Quite a dedicated employee.
Quite a dedicated scientist, willing to put up with irrational attacks from the likes of you, in order to advance actual science.
Again, why, other than out of desperation, would you make a claim that you cannot support with facts, and you know in your heart that you have no evidence to support?
It is commonly held that people engage in ad hominem attacks when they have no facts to support their position. That is, an ad hominem attack is tantamount to an admission that your position is based on belief, rather than facts.