Nearly two years ago, during the COP28 climate summit in the heart of the oil-rich United Arab Emirates, nations committed to begin “transitioning our energy systems away from fossil fuels” to achieve net-zero emissions by 2050. However, the global share of energy sourced from fossil fuels has stubbornly remained over 80 percent, consistent with trends from previous decades.
Due to our inability to decarbonize, researchers now believe we have set off Earth’s first “tipping point,” a significant shift in climate that cannot be easily reversed. Current ocean temperatures are alarmingly high, putting coral reefs at risk of widespread death (see page 9).
What obstacles are impeding the energy transition? While there isn’t a straightforward answer, it is often noted that a select few companies, predominantly fossil fuel corporations, are responsible for the majority of emissions. Criticism of such statements is easy, as they deflect responsibility away from consumers who utilize this energy.
“
Major tech companies are minimizing earlier promises to achieve net zero “
However, it is reasonable to critique oil and gas firms that tout their ecological initiatives yet fail to follow through. Many of these companies promote their renewable energy investments, but in reality, their contributions to future energy production remain minimal (see page 16).
Regrettably, the situation appears poised to worsen before it improves. Encouraged by the Trump administration, numerous oil and gas companies have vowed to boost production, while significant players in other sectors, like tech, are downplaying their net-zero commitments.
Next month, governments are set to convene once more to deliberate on climate policy at COP30 in Brazil. While military action is unlikely from the United States, UK Prime Minister Keir Starmer has yet to confirm his participation. At this juncture, it’s reasonable to question whether any politicians or business leaders genuinely regard the climate change threat seriously. If they do, they must start demonstrating that urgency through action.
Melting ice sheets in Antarctica will elevate sea levels
durktalsma/getty images
Recent studies suggest that Antarctica may have crossed a critical climate threshold, diminishing hope for recovery. Experts highlight a concerning correlation between the abrupt decline in sea ice since 2016 and anthropogenic ocean warming.
Historically, Antarctic sea ice levels remained stable despite rising global temperatures. However, a drastic shift occurred in 2016, marked by significant reductions in sea ice extent.
By February 2023, Antarctic Ocean Ice recorded a new all-time low, marking the third consecutive summer of reduced sea ice within just seven years. September 2023 also saw unprecedented high levels of Antarctic Ocean Ice.
While climate models have long forecasted reductions in Antarctic sea ice, the pace and scale of the decrease since 2016 are alarming. Researchers convened at the Royal Society in London to evaluate whether these changes signal a critical turning point.
As Marilyn Rafael from the University of California, Los Angeles, notes, natural climate variability alone cannot account for such a rapid shift.
Satellite observations of sea ice have been available since 1979. By utilizing proxy data from Antarctic weather stations, Raphael and her team extended their research timeline back to the early 20th century.
Their analysis, based entirely on historical data, indicates that the likelihood of reaching a minimum sea ice extent in 2023 was less than 0.1%. “We are observing extreme patterns in sea ice behavior,” she explained at the Royal Society Conference.
Alexander Hauman from the Alfred Wegener Institute in Germany emphasizes that this rapid decline in ice formation signifies a climate tipping point, with potential repercussions for the entire continent and broader climatic and ecological systems.
“The entire Antarctic sea ice system is reacting collectively,” he stated at the meeting, noting that the changes observed are poised to have long-term implications.
Last summer’s minimum Antarctic Ocean Ice extent was significantly below historical averages
NASA’s Scientific Visualization Studio
Hauman explains that “changes in ice dynamics” may be responsible for this phenomenon. Emerging research indicates that warming seawater contributes to accelerated ice loss, as roughly 90% of the excess heat generated by human activity is absorbed by the oceans.
In Antarctica, a layer of warm, fresh water separates colder, mixed surface waters from warm deep-sea water. However, a recent study by Hauman and his team highlights how shifts in wind patterns and salinity in the Southern Ocean have severely weakened this barrier since 2015, allowing warm deep water to rise to the surface and encourage ice melting. This phenomenon is further exacerbated by climate change-induced warming of deep waters, as indicated by recent research.
Hauman suggests that natural fluctuations in climate may have triggered modifications in salinity and wind patterns, intensifying the effects of anthropogenic warming trapped in deep waters. This could imply that the impact of warming seawater is already being felt in Antarctica, obstructing new sea ice formation.
Hauman notes that recent shifts in ocean circulation can only be counteracted by either mitigating upwelling effects or sudden alterations in salinity within the Southern Ocean. Nevertheless, the potential responses of the system remain highly uncertain.
The ramifications of these developments could be catastrophic. Antarctic sea ice plays a critical role in stabilizing land glaciers and ice sheets. Without adequate sea ice formation, the rate at which these ice structures melt may increase, leading to significant global sea level rise. It is estimated that the Antarctic ice sheet holds enough water to potentially raise global sea levels by up to 58 meters.
The depletion of ice in the Antarctic also alters the Earth’s surface albedo. Darker oceans absorb more solar heat compared to reflective white ice.
Additionally, vast stores of carbon trapped in the Southern Ocean could be released into the atmosphere as deep-sea temperatures rise, as suggested by various studies.
Researchers are just starting to grasp how these types of climate feedback mechanisms might unfold in Antarctica, after many years of relying on inaccurate and low-resolution models.
Scientists warn that the Amazon Rainforest has experienced a loss of the rainfall necessary to sustain it, pushing the world’s largest tropical ecosystem toward a potential tipping point.
A recent study published in Nature Communications indicates that deforestation is causing a significant decline in rainfall during the Amazon’s dry season, thereby increasing heat across the region.
Researchers suggest these changes could signify “early signs of biome destabilization,” implying that the forests are beginning to struggle to maintain their balance.
The study analyzed satellite and climate data from 1985 to 2020, encompassing an area of 2.6 million km² (1,000,000 square miles) in Brazil’s Amazon. This is nearly four times larger than Texas.
The data revealed that dry season rainfall has decreased by approximately 21mm (0.8 inches), with about three-quarters of this decline directly associated with deforestation.
During the same period, maximum daily temperatures increased by around 2°C (3.6°F), with 16.5% of this rise attributable to forest loss, while the remainder results from global climate change.
Deforestation contributes to reduced rainfall, while increased methane and carbon dioxide levels result from climate change – Source: Machado et al., Nature Communications (2025)
Plants play a crucial role in the Amazon’s rain cycle by extracting water from the soil and releasing it through a process known as transpiration.
When trees are removed, this cycle weakens, leading to fewer clouds and less rainfall. Consequently, the forest becomes hotter and drier, creating a harmful feedback loop.
If the Amazon reaches a tipping point, it may no longer be able to sustain itself, resulting in a rapid and irreversible collapse of the ecosystem and converting the region into a savanna.
This shift would significantly impact the entire water cycle in South America and release the carbon stored in the rainforests.
“These findings underscore the necessity of preserving and restoring Amazonian forest cover as a vital strategy for mitigating climate change and ensuring ecosystem stability,” the scientists conclude.
Incorporating sunlight-reflecting particles into the atmosphere may help mitigate climate change
Alexnako/Shutterstock
Continuing to emit carbon dioxide poses significant threats, including the risk of triggering tipping points that can lead to major disruptions such as the shutdown of critical ocean currents. Current modeling indicates that injecting aerosols into the stratosphere to reflect sunlight could mitigate this risk, though the effectiveness diminishes significantly if it is initiated much later, such as in 2080.
“My conclusion is that if we are genuinely committed to preventing climate change, we must take solar radiation management seriously. This includes exploring its potential advantages and drawbacks,” declared Claudia Winners from Utrecht University in the Netherlands.
A tipping point signifies changes that are irreversible for centuries, including the slowing or stopping of critical marine currents that distribute immense amounts of heat, impacting the global climate.
One such current is the Atlantic Meridional Overturning Circulation (AMOC), which transfers heat from the tropics to Europe. A collapse of this system could instigate rapid sea level rises in North America, severe temperature decreases in Northern Europe, and significant disruptions to the Asian monsoon.
Stratospheric aerosol injection represents a proposed geoengineering method that involves the dispersal of sun-reflective particles in the upper atmosphere via airplanes, balloons, or rockets.
According to the model employed by Winners’ team, the strength of AMOC could decrease by over 50% in the coming century under a worst-case emissions scenario. However, utilizing stratospheric aerosol injections to maintain global temperatures around 1.5°C could significantly mitigate current weakening, as Winners explained at the Exeter Climate Conference held in the UK last week.
Indeed, AMOC would not dip below this scenario under aggressive emissions reductions without geoengineering. “So, for at least the next 80 years, the effectiveness of stratospheric aerosol injections is higher than the mitigation from greenhouse gases,” Winners stated.
However, the model indicates that AMOC would fail to recover if aerosol injections are delayed until 2080, especially if they are employed to bring global temperatures back above 1.5°C after an overshoot, as suggested by the model.
The team also examined subpolar gyres in the North Atlantic, a circular current linked to AMOC that circulates around areas where cold, saline water sinks. If this sinking process halts because the oceans become fresher and warmer, it will significantly affect the climate in Europe.
In a worst-case scenario, the model predicts that sinking will cease and that commencing stratospheric aerosol injections in 2080 would not reactive the process. However, if injections start now, subsidence could be preserved in two out of the three crucial regions.
Nevertheless, these findings necessitate validation through numerous studies examining more realistic emission scenarios, as there are potential risks involved, according to Winners. “You can really mess it up too,” she cautioned.
For successful geoengineering, sustained global cooperation over centuries will be paramount. “You might say this is the largest governance challenge humanity has ever faced,” articulated ethicist Stephen Gardiner during another session at the conference from Washington University in Seattle.
For instance, if stratospheric aerosol injections are only conducted in one hemisphere without a global consensus, Winners warns that it could alter tropical rainfall patterns worldwide.
In a subsequent presentation, Jim Heywood from the University of Exeter discussed another geoengineering method, known as marine cloud brightening, which demonstrated that localized interventions could potentially incite global climatic changes.
With the risks now understood, they can be circumvented, said Haywood. “It’s merely a shift in strategy.” Yet, many researchers remain skeptical about the feasibility of managing geoengineering risks.
“Solar radiation management sounds entirely manageable. Shouldn’t we refer to it as solar radiation interference?” Stephen Rahmstorf questioned Winners after her presentation at the University of Potsdam in Germany.
There is also a concern that geoengineering could be perceived as an alternative to emission reductions. “We are not addressing the root causes of climate change,” stated Winners. “It’s merely a symptom management strategy; however, if the symptoms deteriorate excessively, it may complement a true solution.”
Due to these concerns, some climate scientists oppose even investigating the potential risks and advantages of geoengineering. The topic has become so contentious that participants at at least one meeting opted out of a session focused on it.
Winners is not the first to assert that geoengineering might need to commence immediately to avert tipping points. Last year, two independent teams concluded that solar radiation management could prevent the collapse of the West Antarctic ice sheet, another significant tipping point.
“It stands to reason that delaying increases the risk of irreversible changes,” Winners mentioned to New Scientist following her presentation. “I believe that’s quite clear.”
If you want to unsettle climate scientists, simply stand next to them and quietly mention the phrase “tipping point” in their ear. While climate change due to global warming is already concerning, the concept of climate tipping points adds an extra layer of fear. But what exactly are they and why are they causing alarm?
We find ourselves in a unique time where Earth’s average temperature is increasing at a rate at least 10 times faster than ever recorded in geological history. This has led to a surge in extreme weather events, melting ice sheets, and rising sea levels. Despite these clear signs, greenhouse gas emissions continue to rise rapidly, with global temperatures increasing by 1.64°C (nearly 3°F) in the past year alone. As a result, the possibility of irreversible and drastic changes in the climate system becomes more and more likely.
Tipping points are named as such because they require a critical threshold to be crossed before a significant change occurs. Once activated, like a seesaw tipping over, there is no turning back. These moments, as defined by the American Cultural Heritage English Dictionary, are described as “a critical moment in a complex situation where a small influence or development suddenly produces a large or irreversible change.” This holds true for the climate crisis we face.
How things shift
One of the challenges for scientists studying global warming is the unpredictability of tipping points in terms of timing and impact. Additionally, how these points are integrated into climate models can greatly affect predictions of future climate change. The complexity of the climate system suggests that there are numerous tipping points, with nine identified as having the potential to trigger significant global environmental changes.
These include the potential collapse of the Greenland and West Antarctic ice sheets, dieback of the Amazon rainforest, and release of methane from melting Arctic permafrost. Each of these events could have far-reaching consequences, from massive sea level rise to increased carbon levels in the atmosphere.
While some of these tipping points may seem distant, the looming collapse of the Gulf Stream and associated ocean currents presents an immediate concern. Previously considered unlikely, recent data suggests that this crucial system may be on the brink of destabilization sooner than expected, posing a threat to the UK and Northern Europe’s climate stability.
Recent research suggests Antarctic ice sheets may be melting faster than existing models predict – Photo courtesy of Getty Images
The Earth’s great engine
Understanding the significance of AMOC’s collapse requires knowledge of its role as a key component of the global ocean current system. This system, known as the global conveyor belt, transports heat from the tropics to the Arctic, playing a crucial role in global climate and weather patterns.
The sheer scale of AMOC’s operation is astounding, moving millions of cubic meters of water and gigawatts of heat every second. However, disruptions to this system, such as increased freshwater input from melting ice, can hinder AMOC’s ability to function properly, potentially causing a shutdown with severe global consequences.
If AMOC were to fail, global weather patterns would be disrupted, leading to a range of impacts from cooler temperatures in Europe to altered monsoons in Asia and Africa. The effects would be felt globally, with implications for food security, migration patterns, and geopolitical stability.
The artificial intelligence boom has pushed demand for Nvidia products beyond Wall Street’s already high expectations.
The company announced fourth-quarter results on Wednesday that significantly beat analysts’ expectations, with revenue of $22.1 billion versus the $20.55 billion expected and earnings of $4.93 per share versus the $4.64 expected. became. Revenue increased 22% sequentially and 265% year over year.
Revenue from data centers, Nvidia’s most-watched revenue, increased more than 400% year-over-year to $18.4 billion.
Nvidia founder and CEO Jensen Huang said in a press release: “Accelerated computing and generative AI have reached a tipping point. Demand is surging around the world across companies, industries, and nations.”
Nvidia’s earnings and stock demand are seen as a bellwether for overall interest in artificial intelligence, as the company relies heavily on its products to develop AI. Microsoft, OpenAI, Amazon, Meta, and Google have all signed deals to buy the company’s chips in bulk as they race to release new AI products and features.
Some major companies, including OpenAI’s Sam Altman, are launching their own AI chip ventures to compete with established Nvidia, which would likely cost hundreds of billions of dollars. .
Nvidia plans to ship a new chip, the B100, which will be the top of its product line, in 2024, raising expectations for explosive growth. Nokia and Nvidia on Wednesday announced a partnership to develop AI solutions that can improve communications infrastructure.
Wall Street has come to expect big growth from Nvidia. Analysts’ baseline forecast on Wednesday was for sales to increase his 240%. Tech companies are rushing to develop AI products that leverage the company’s proprietary AI chips and software, considered the best on the market.
Nvidia’s revenue tripled last quarter, and its profits for the past four quarters have exceeded analyst expectations.
The company’s stock price has more than tripled over the past year, valuing the company at more than $1.5 trillion. The company surpassed Google and Amazon in market capitalization last week, making it the world’s third-largest company by value within days.
Large parts of the Amazon rainforest are threatened by the combined effects of drought, heat and deforestation, and some ecosystems may be pushed past tipping points. But the likelihood of a larger collapse remains uncertain.
“Forests as a whole are very resilient, so we still have room to act,” he says. Marina Hirota at the Federal University of Santa Catarina, Brazil.
Researchers have warned for decades that rising temperatures and deforestation could push the Amazon past a tipping point, leading to runaway feedbacks that could lead to a rapid transition from forest to savannah. The drought and heat caused by the ongoing El Niño phenomenon, as well as the warming temperatures caused by climate change, are once again on the rise.
But climate and ecological models that describe the Amazon's highly complex structure disagree on when and where such a tipping point would occur.
To understand which regions of the Amazon are most at risk, Hirota and his colleagues looked at satellite data to see how several different ecosystem stressors might change in the coming decades. evaluated. These include dry season temperatures, exposure to drought, and the risk of fire and deforestation.
They estimate that 10 percent of the Amazon basin is at risk of being exposed to at least two of these stressors by 2050 and is therefore likely to transition to degraded forest- or savanna-like ecosystems. I discovered that. 47% of this watershed is predicted to be exposed to at least one stressor, meaning it is also exposed to some hazard.
“Due to ongoing changes, we will lose some forest, but there are things we can do to prevent it from reaching 47%,” Hirota says. She said the majority of forests that are not exposed to stressors are located within protected areas; indigenous territory, which is associated with low deforestation rates. Brazil's deforestation rate also fell sharply under President Luiz Inacio Lula da Silva's administration. Increased in other areas as well Amazon's.
dominique spracklen Researchers from the University of Leeds in the UK say the study is a powerful investigation into the range of threats facing the Amazon. But he says the discrepancies between models predicting potential tipping points remain unresolved.
For example, models predict that some of the negative effects of warming could be offset by increased concentrations of CO2 in the atmosphere, which could boost plant growth. . However, other factors such as nutrients and water availability vary widely across the basin and influence the strength of this impact, creating considerable uncertainty in modeling the future of the Amazon. .
“It's a very scary place for such an important ecosystem,” he says.
This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.
Strictly Necessary Cookies
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
