A new study reveals that before northern Africa dried out, 5,500 years ago, its climate “flickered” between two stable climatic states before tipping permanently. This is the first time it’s been shown such flickering happened in Earth’s past. And it suggests that places with highly variable cycles of changing climate today may in some cases be headed for tipping points of their own.
Is the Atlantic Overturning Circulation Approaching a #TippingPoint?
Studies show that the Atlantic Meridional Overturning Circulation (#AMOC) has already weakened as a result of anthropogenic #ClimateChange and is possible moving towards a tipping point. This current has a significant influence on #climate, particularly in #Europe.
"For the first time, some of the fastest-growing markets were found in Eastern Europe and Southeast Asia. The trajectory laid out by countries that came before them shows how #EVs can surge from 5% to 25% of new cars in under four years.
While each country’s journey to 5% plays out differently, timelines converge in the years that follow."
"The Global Tipping Points Report was launched at COP28 on 6 December 2023. The report is an authoritative assessment of the risks and opportunities of both negative and positive tipping points in the Earth system and society."
This is an oceanographic phenomenon worthy of our attention and alarm. Lots of talk about #TippingPoint events lately, with good reason. This is one of the most important to track, with profound global implications for #ClimateChange and #ExtinctionEvent triggering. If the #AMOC becomes more unstable, as it is doing every year, it WILL collapse - within a few generations. And that, my friends, will change the world in dramatic ways. We don’t want to go there, but are well on our way. #Oceans#Oceanography#AtlanticCurrents#ClimateCrisis#ClimateEmergency
"by 2050, 10% to 47% of Amazonian forests will be exposed to compounding disturbances that may trigger unexpected ecosystem transitions ... inherent complexity of the Amazon adds uncertainty about future dynamics, but also reveals opportunities for action... a combination of local efforts to end deforestation and degradation and to expand restoration, with global efforts to stop greenhouse gas emissions."
Atlantic Ocean is headed for a tipping point − once melting glaciers shut down the Gulf Stream, we would see extreme #ClimateChange within decades, study shows
"The results showed that it’s headed in that direction. If that happened, average temperatures would drop by several degrees in North America, parts of Asia and Europe, and people would see severe and cascading consequences around the world."
"A full #AMOC collapse would be a massive, planetary-scale disaster. We really want to prevent this from happening.
We are talking about risk analysis and disaster prevention. This is not about being 100% or even just 50% sure that the AMOC will pass its #TippingPoint this century; the issue is that we’d like to be 100% sure that it won’t.
The studies discussed here, which came after the 2021 IPCC report, point to a much larger risk than previously thought."
"If you stopped cultivating your own website because you really liked #Twitter… did you really care about it that much?
If you care about the #indieweb growing, by all means write, by all means create, by all means curate. But most of all, just read. Or listen, or experience. Spend an afternoon clicking around, like everybody used to.
If 2024 truly is a #tippingpoint into a new world, then it can’t happen in a vacuum."
👀 "The marine-based West Antarctic Ice Sheet (WAIS) is considered vulnerable to irreversible collapse under future climate trajectories, and its tipping point may lie within the mitigated warming scenarios of 1.5° to 2°C of the United Nations Paris Agreement. ... Using a panel of genome-wide, single-nucleotide polymorphisms of a circum-Antarctic octopus, we show persistent, historic signals of gene flow only possible with complete WAIS collapse. Our results provide the first empirical evidence that the tipping point of WAIS loss could be reached even under stringent climate mitigation scenarios." #climate#tippingpoint#octopus#dnahttps://www.science.org/doi/10.1126/science.ade0664
>Record-breaking land and sea temperatures, driven by climate breakdown, will probably cause “unprecedented mass coral bleaching and mortality” throughout 2024, according to a pioneering coral scientist.
>The impact of climate change on coral reefs has reached “uncharted territory”, said Prof Ove Hoegh-Guldberg, from the University of Queensland, Australia, leading to concerns that we could be at a “tipping point”
"Humanity faces ‘devastating domino effects’ including mass displacement and financial ruin as planet warms.
The #TippingPoints at risk include the collapse of big #IceSheets in Greenland and the West Antarctic, the widespread thawing of #permafrost, the death of #CoralReefs in warm waters, and the collapse of one oceanic current in the North Atlantic."
"“Policy-makers need to think systemically and look for those leverage points where small interventions can make a big difference,” says Powell.
But triggering one positive #TippingPoint can sometimes help trigger others, like dominoes, he says. For instance, the adoption of electric vehicles is bringing down battery prices, which then makes it feasible to use batteries to back up the intermittent electricity supply from renewable sources."
deeply depressed. just read that the amazon rainforest, home to thousands of bird species (including at least 1/3 of all living parrot species) has crossed a #climate & #deforestation#TippingPoint & will quickly devolve into savannah. all this destruction for a cheap fcuking HAMBURGER
Unavoidable future increase in West Antarctic ice-shelf melting over the 21st Century
The collapse of the West #Antarctic Ice Sheet is a worrying climate #tippingpoint, with the potential to raise global sea level by up to 5.3m. Now, an assessment of future #climate scenarios suggests that accelerated melting of ice shelves in West Antarctica is locked in, even for the most ambitious emissions reduction scenarios.
> The research helps to solidify an understanding that humans have probably already pushed some polar ice systems past a tipping point and into escalating decline.
... the analysis could mean scientists were too conservative in predicting about one to three feet of sea level rise by 2100.
"South American #monsoon heading towards ‘tipping point’ likely to cause Amazon dieback - ‘Shocking’ study finds #Amazon#rainforest will be unable to sustain itself and transport moisture once ‘regime shift’ occurs - The South American monsoon, which determines the climate of much of the continent, is being pushed towards a “critical destabilisation point”, according to a study that links regional rainfall to Amazon deforestation and global heating.
The authors of the report said they found their results “shocking” and urged policymakers to act with urgency to forestall a tipping point, which could result in up to 30% less rainfall, a dieback of the forest and a dire impact on food production.
...
Human degradation of the Amazon – by land clearance, fire, logging and mining – is pushing that system towards a tipping point, after which drier conditions would be expected to cause an abrupt “regime shift” in the rainforest, which would be unable to sustain itself and transport moisture.
Other biomes in the region would also be affected, along with swathes of agricultural land because the monsoon stretches thousands of miles south from the Amazon to the River Plate (Rio de la Plata) basin. There would also be a climate impact because the Amazon – which would be worst affected – has historically served as an important carbon sink, though another study this week suggests it is now so degraded that it is at best carbon neutral. A dieback of the forest would release enormous amounts of carbon.
...
The researchers on the Amazon-monsoon paper saw several precursors of the tipping point, including falling rainfall in many areas, the steady lengthening of the Amazon dry season, reduced soil moisture and the increasing frequency and intensity of droughts. There have been three statistically one-in-100-year droughts in the space of a single decade.
“It is shocking to see these signs of destabilisation,” said the lead author, Nils Bochow, of the University of Tromsø and the Potsdam Institute of Climate Impact Research. “But we shouldn’t lose hope. We can still act. We need stricter rules regarding the rainforest.”
The original article's Discussion section does an excellent job describing the various interactions and feedback loops which ultimately lead to crossing the Amazon's #TippingPoint, the "alternative equilibrium" referred to in the text. I've added numbering to try to make the steps/interactions a little clearer. (I have also removed the footnote references). Figure 5 is reproduced on my main post.
"In accordance with our model results, we propose the following chain of mechanisms in the coupled atmosphere-vegetation dynamics on the way to the deforestation-induced transition.
(1) The time needed to initiate the wet season prolongs as the atmospheric moisture and, hence, the average latent heat over the Amazon decreases with proceeding forest loss in the east. Large parts of Amazonia show a negative trend in atmospheric moisture content over the past decades.
(2) The heating gradient between the Atlantic Ocean and the continent weakens and impedes the annual transition into the wet season. Consistently, we observe increasing DSL (Drry Season Length) and later wet season onset in the ERA5 data (Fig. 5B). The shortened wet season and the decreasing rainfall rates result in lower soil moisture levels. Evapotranspiration rates, however, stay at a high level and further deplete the soil during the dry season. This leads to an all-year-round decrease of the soil moisture and an increasing SMD (Soil Moisture Deficit) before the dieback of the rainforest. This increasing SMD can be clearly observed in the ERA5 data (Fig. 5A).
(3) After the dieback of the rainforest, the soil moisture approaches an alternative equilibrium consistent with the reduced precipitation and evapotranspiration of the savanna vegetation. At the critical point, the atmospheric moisture content does not suffice anymore to maintain precipitation and, thus, latent heating rates that could switch the system back into the annual wet season, resulting in a permanent dry season state. Consequently, this would result in a dieback of substantial parts of the rainforest."
Human degradation of the #Amazon – by land clearance, fire, logging and mining – is pushing that system towards a tipping point, after which drier conditions would be expected to cause an abrupt “regime shift” in the rainforest, which would be unable to sustain itself and transport moisture."
"Previous studies have suggested a #TippingPoint could be reached when 20% to 30% of the Amazon is cleared, though there is considerable uncertainty about exactly where the point might be. Currently, between 17% and 26% of the #rainforest has been destroyed and at least that has been degraded."
Deforestation in Brazil has slowed considerably under Lula. But it needs to be stopped completely. You can help that, by eating less meat.