Tag Archives: 1.5C

Achieving the 1.5°C Climate Goal: The Century’s Best Vision for a Sustainable Future

Posted on by
Reply

New Scientist - Your source for groundbreaking science news and in-depth articles on technology, health, and the environment.

During the first decade of the 21st century, scientists and policymakers emphasized a 2°C cap as the highest “safe” limit for global warming above pre-industrial levels. Recent research suggests that this threshold might still be too high. Rising sea levels pose a significant risk to low-lying islands, prompting scientists to explore the advantages of capping temperature rise at approximately 1.5°C for safeguarding vulnerable regions.

In light of this evidence, the United Nations negotiating bloc, the Alliance of Small Island States (AOSIS), advocated for a global commitment to restrict warming to 1.5°C, emphasizing that allowing a 2°C increase would have devastating effects on many small island developing nations.

James Fletcher, the former UN negotiator for the AOSIS bloc at the 2015 UN COP climate change summit in Paris, remarked on the challenges faced in convincing other nations to adopt this stricter global objective. At one summit, he recounted a low-income country’s representative confronting him, expressing their vehement opposition to the idea of even a 1.5°C increase.

After intense discussions, bolstered by support from the European Union and the tacit backing of the United States, as well as intervention from Pope Francis, the 1.5°C target was included in the impactful 2015 Paris Agreement. However, climate scientists commenced their work without a formal evaluation of the implications of this warming level.

In 2018, the Intergovernmental Panel on Climate Change report confirmed that limiting warming to 1.5°C would provide substantial benefits. The report also advocated for achieving net-zero emissions by 2050 along a 1.5°C pathway.

These dual objectives quickly became rallying points for nations and businesses worldwide, persuading countries like the UK to enhance their national climate commitments to meet these stringently set goals.

Researchers at the University of Leeds, including Piers Foster, attribute the influence of the 1.5°C target as a catalyst driving nations to adhere to significantly tougher climate goals than previously envisioned. “It fostered a sense of urgency,” he remarks.

Despite this momentum, global temperatures continue to rise, and current efforts to curb emissions are insufficient to fulfill the 1.5°C commitment. Scientific assessments predict the world may exceed this warming threshold within a mere few years.

Nevertheless, 1.5°C remains a crucial benchmark for tracking progress in global emissions reductions. Public and policymakers are more alert than ever to the implications of rising temperatures. An overshoot beyond 1.5°C is widely regarded as a perilous scenario, rendering the prior notion of 2°C as a “safe” threshold increasingly outdated.

Topic:

Source: www.newscientist.com

Even with Global Warming Capped at 1.5°C, Sea Levels Will Surge Quickly

Posted on by
Reply
SEI 252158269

Rising seas pose a significant threat to coastal cities.

Hugh R Hastings/Getty Images

A recent review of the latest scientific data indicates that capping global warming at 1.5°C above pre-industrial levels won’t halt sea level rise for centuries to come.

“There seems to be a widespread belief that reaching 1.5°C will solve all our problems,” explained Chris Stokes from Durham University, UK. “While it should certainly be our goal, it won’t prevent sea level rise caused by the melting ice sheets.”

At present, global warming is on track for approximately 2.9°C by 2100, noted Jonathan Bamber from the University of Bristol, UK. “In terms of long-term impacts, we’re looking at a potential sea level rise of over 12 meters,” he stated.

Stokes, Bamber, and their colleagues have compiled data from satellite observations of ice loss and rising sea levels over the last three decades, historical data from warm periods, and satellite insights from models of ice sheets.

Older models that fail to incorporate crucial processes suggest that ice sheets take a significant amount of time to respond to warming, according to Bamber. However, satellite data indicates that the Greenland and West Antarctic ice sheets are reacting much more swiftly.

“The data presents a very different narrative,” Bamber remarked. “The mass loss observed in Greenland is astonishing and truly unprecedented compared to model predictions.”

Both Greenland and West Antarctica are not only losing ice, but their rates of loss are increasing, said Stokes. “And this is occurring with just 1.2 degrees of warming,” he pointed out. “The notion that limiting warming to 1.5°C would resolve this is misleading.”

Research on previous warm spells over the past three million years reveals that sea levels were significantly higher during those times, as stated by Stokes.

The most recent report from the Intergovernmental Panel on Climate Change (IPCC), published in 2021, forecasts a sea level rise of 1 to 2 meters over the coming centuries if global temperature rise is curtailed to 1.5°C, according to Stokes.

“We are pushing these projections forward,” he said. “It’s becoming evident that we are witnessing some of the worst-case scenarios manifesting right before us, based on mass balance satellite data.”

The team estimates that merely mitigating the pace of sea level rise from melting ice sheets to manageable levels will require the average global temperature to remain below 1°C above pre-industrial levels.

While wealthier nations may bolster their coastlines against rising seas, as ocean levels continue to escalate, this becomes more challenging and costly, Bamber warned. “Certain countries simply lack the financial resources for such measures.”

This highlights the urgency of taking action, according to Stokes. “Every fraction of a degree is crucial to the ice sheet,” he stated. “While I may alter certain points and thresholds, it’s vital to recognize that all degrees matter.”

Topics:

Source: www.newscientist.com

Earth Approaches a Second Year Exceeding the 1.5°C Climate Goal

Posted on by
Reply

A Sunset Over London in May 2025

Guy Corbishley/Alamy

The aim of restricting global warming to below 1.5°C faces challenges as recent climate data suggests global temperatures remain alarmingly high, with 2025 tracking closely to 2024’s record heat.

April 2025 marked the second hottest April on record, losing out only to April 2024, as per reports from the European Union’s Copernicus climate service and the nonprofit Berkeley Earth. That month, global temperatures consistently exceeded 1.51°C above pre-industrial levels, marking 22 consecutive months over this critical threshold. Copernicus reports. The average temperature for April 2025 remained cooler than April 2024, still surpassing pre-industrial levels by 1.49°C.

This unrelenting warmth has astounded scientists. The year 2024 was deemed the hottest on record, with an average global temperature exceeding 1.55°C above the pre-industrial average. It marked a significant event as it was the first calendar year to surpass the 1.5°C threshold. Under the 2015 Paris Climate Agreement, nations pledged to limit global temperature increases to well below 2°C, ideally to 1.5°C.

Scientists had anticipated that the cooling effects of the La Niña weather pattern would emerge in January, offering some relief. However, global temperatures have remained persistently elevated, raising concerns about 2025 possibly following 2024 in exceeding the critical 1.5°C marker. “The recent La Niña event hasn’t provided the expected cooling relief,” stated Robert Rohde from Berkeley Earth during a briefing on May 13.

Data from Berkeley Earth suggests an 18% likelihood that 2025 will be the hottest year recorded, and a 53% chance of it being the second hottest. Rohde estimates a 52% probability of having an average temperature exceeding 1.5°C this year.

The trajectory of global temperatures for the remainder of the year relies heavily on whether new El Niño or La Niña patterns emerge in the Pacific, according to Rohde.

The ongoing hot streak has dashed hopes of capping global temperatures at the 1.5°C Paris target. Although targets are assessed over a 20-year average, researchers are increasingly worried that recent high-temperature streaks have led to a breach of this threshold. “It’s becoming inevitable that we’ll see a long-term average above 1.5°C in the next decade,” Rohde cautioned.

Last year, scientists warned that exceeding 1.5°C would result in a three-year period of significant temperature rise, effectively compromising the goals of the Paris Agreement. Similarly, a paper released earlier this year indicated that 12 consecutive months above 1.5°C have already signaled a long-term warming trend at that level.

Richard Allan from the University of Reading expressed surprise at the durability of the warmth. Findings from the past two years and new record temperatures have fundamentally altered the scientific perspective on the feasibility of limiting warming to 1.5°C. “Without substantial mitigation efforts or extraordinary volcanic events in the next 20 years, we expect we will be above the 1.5°C threshold,” he remarked.

Nevertheless, he maintains that the Paris Agreement’s goal of limiting warming to below 2°C remains attainable. “It is crucial to strive for temperatures beneath that threshold,” he emphasized.

Topics:

  • Temperature/
  • Paris Climate Summit

Source: www.newscientist.com

Temperatures Expected to Decrease to Below 1.5°C by 2025 According to Global Forecasts

Posted on by
Reply

Severe storms caused by La Niña in Queensland, Australia

Genevieve Vallee/Alamy Stock Photo

The UK's national weather and climate agency, the Met Office, predicts that the Earth's average surface temperature in 2025 will be between 1.29°C and 1.53°C warmer than the pre-industrial average, and possibly 1.41°C. This is slightly lower than 2024, when temperatures are expected to exceed 1.5°C for the first time in the calendar year.

“A year ago, our 2024 forecasts highlighted for the first time the potential for temperatures to exceed 1.5C,” the Met Office's Nick Dunstone said in a statement. “While this appears to have happened, it is important to realize that temporarily exceeding 1.5°C does not mean a violation of the Paris Agreement. However, the first year above 1.5°C It is certainly a solemn milestone in climate history.”

The Paris Agreement set a goal of limiting global warming to 1.5°C to 2°C above pre-industrial standards. Most climate scientists currently define pre-industrial temperature as the Earth's average surface temperature between 1850 and 1900. This is because this is the earliest period for which reliable direct measurements were obtained. However, some studies suggest that by that time, the world had already warmed significantly as a result of human activity.

Next year will be among the top three warmest years on record, according to 2025 projections

Japan Meteorological Agency

The expected drop in surface temperatures in 2025 is the result of heat transfer from the atmosphere to the oceans due to La Niña, and does not mean that global warming has stopped. The overall heat content of the oceans and atmosphere continues to rise as atmospheric carbon dioxide concentrations are rising due to increased carbon dioxide emissions from human activities.

During a La Niña event, cold water rises in the Pacific Ocean and spreads across the Earth's surface, resulting in a net heat transfer from the atmosphere to the ocean. When an El Niño event occurs, the opposite happens. The 2023 El Niño helped break records for surface temperatures that year, which will be surpassed in 2024. But El Niño alone cannot fully explain the record temperatures.

topic:

Source: www.newscientist.com

The Earth has been warmed by 1.5°C due to human activity since 1700

Posted on by
Reply

Bubbles trapped in Antarctic ice were used to estimate past temperatures

aldiami/Andreas Alexander/Alamy

Humankind has already caused around 1.5 degrees Celsius of warming since the start of the industrial revolution, according to new estimates based on temperature data collected from air bubbles trapped in ice.

Measuring anthropogenic global warming typically uses the period from 1850 to 1900 as a pre-industrial baseline. This is because this is the time when temperature records began. 2024 is almost certain to be the first year in which average temperatures rise by more than 1.5 degrees Celsius above this baseline. This single-year data is influenced by naturally occurring factors such as the strong El Niño event, which has pushed up global temperatures.

When you remove this natural variation, scientists believe humans alone have caused 1.31°C of warming since the Industrial Revolution. But by 1850, the Industrial Revolution was already underway, and fossil fuel-powered engines were in use around the world.

Andrew Jarvis Lancaster University and Piers Foster Researchers at the University of Leeds, both in the UK, set out to establish a new pre-industrial baseline using data taken from Antarctic ice core samples. The pair analyzed the composition of air bubbles trapped in ice cores to establish atmospheric carbon dioxide concentrations from 13 AD to 1700, before humans significantly influenced atmospheric temperatures. This CO2 data was then used to establish the average global temperature over the same period, assuming a linear relationship between CO2 and temperature increases.

Using this new pre-1700 baseline, humanity has caused 1.49°C of warming by 2023, meaning the 1.5°C level has been “effectively reached,” the researchers say in their findings. It is written in the paper to be reported. “We have provided a new, scientifically defensible way to derive a pre-industrial baseline for measuring global warming,” Jarvis told reporters at a press conference.

Jarvis said the new method would also help reduce the uncertainty in temperature estimates based on the current 1850-1900 baseline used by the Intergovernmental Panel on Climate Change. Using ice core data to establish a baseline between 1850 and 1900, the researchers say humans caused 1.31°C of warming. This is consistent with existing median estimates, but the range of uncertainty is significantly reduced, the researchers note.

“The problem with just looking at surface temperature observations is that the further back in time you go, the more uncertain those observations become,” Forster says. “We are now much more confident than before that the current temperature is around 1.3°C.”

Jarvis and Forster hope their new method will be adopted by scientists and policymakers as the primary way to judge humanity's progress against global climate goals. “I think there is still room in the policy and scientific communities to rethink the pre-industrial baseline,” Jarvis said. “We know that the estimates for 1850 to 1900 incorporate warming, simply because that was not the beginning of the industrial revolution. We provide a way to operate from a secure baseline.”

However, new methods may not be future-proof. The linear relationship between CO2 concentrations and global temperatures is likely to break down as the climate changes. For example, if a so-called tipping point is triggered in the Earth system that triggers a series of warming events.

The new methods won't change the effects of climate change that are felt on the ground, Forster said. “The impact on human life from Spain and the hurricanes we are experiencing today is exactly the same whether you call it 1.3°C above pre-industrial levels or 1.5°C above pre-industrial levels. is” . Influence is influence. ”

Richard Betts The Met Office, the UK's meteorological agency, said the new method “provides a clear and easy way to provide an up-to-date estimate of the current level of anthropogenic global warming”. Part of the reason is that it can produce “real-time” estimates of human-induced warming, rather than relying on 10-year moving averages as current estimates do.

He said the approach could help provide policymakers with a more up-to-date picture of current levels of warming, but changing the baseline used in the assessment would be an “objective” for climate action. It warned that it could be considered as “moving.'' “Even without changing the baseline, it is clear that current warming is much closer to 1.5°C than expected using older 10-year averages,” he says .

topic:

Source: www.newscientist.com

The 1.5°C target may be out of reach, but climate action is still crucial

Posted on by
Reply

AP Photo/François Mori, File/Alamy

As a COP26 During climate change negotiations in Glasgow, UK, in November 2021, a new slogan entered the vocabulary: “Stay at 1.5°C.” The phrase, on everyone’s lips from politicians to climate scientists, was aimed at maintaining the goals set as part of the Paris Agreement at the COP six years ago.twenty oneIn hindsight, this ambition was probably already fizzling out, destined to remain merely an empty slogan.

New Scientist The argument began in 2022, when expert opinion did not reflect their personal views or the data we were seeing. Scientists felt trapped and unable to speak out because limiting warming to 1.5°C above pre-industrial levels is still possible according to the laws of physics, but not realistic given the political, social and economic upheaval.

Since then, there has been a growing recognition that 1.5°C is unattainable, but there was no frank discussion of what that meant. Now, for the first time, researchers have explicitly rejected that, saying that 1.6°C is the best we can hope for, and that higher temperatures are more likely (see “Best-case scenario for climate change now is 1.6°C warming”).

Will policymakers finally realize that platitudes and slogans are not enough to combat climate change? Promises to “maintain” these targets are meaningless if we do not achieve the only means of preventing rising temperatures — reducing emissions of carbon dioxide and other global-warming greenhouse gases to net zero.

Unfortunately, the phrase “net zero” is losing its original meaning as a description of atmospheric physics, and instead being used by many to mean “environmental policy I don’t like.” This is dangerous, because extreme temperature changes have locked us in a vicious cycle of emissions that only a net-zero energy system can break (see “Efforts to combat extreme temperatures are making the situation worse”). If we are to have any hope of limiting warming, we need to learn from the failure of “stay 1.5°C” and not let “net zero” become meaningless.

topic:

Source: www.newscientist.com

It is possible that global temperatures surpassed 1.5°C of warming a decade ago.

Posted on by
Reply

Activists participating in COP28 climate change conference to be held in Dubai in December 2023

Sean Gallup/Getty Images

The 1.5°C limit was exceeded in 2010 or 2011, and the world is already 1.8°C warmer than it was before the industrial revolution, according to researchers using sponges to find out how seawater and air temperatures in the Caribbean have changed through 2018. The researchers who investigated this claim. Past 300 years.

“The increase in Earth's average surface temperature was 0.5 degrees Celsius greater than currently accepted estimates.” Malcolm McCulloch at the University of Western Australia. “What our research shows is that global warming scenarios are 10 years away, or even further.”

But other climate scientists argue that data from a single region is not a reliable way to understand past global temperatures.

The 2015 Paris Agreement called on countries to limit global warming to 1.5 degrees Celsius above pre-industrial levels, but it did not define exactly what this meant. So climate scientists compiling the Intergovernmental Panel on Climate Change (IPCC) report defined it as the average temperature from 1850 to 1900.

By this time, the Earth had already begun to warm as a result of emissions from burning fossil fuels. However, because there were few temperature measurements before 1850, there is great uncertainty about how much warming was caused by fossil fuels during the early industrial era. Therefore, choosing 1850–1900 as the baseline was pragmatic.

But McCulloch and his colleagues think they have discovered exactly what fossil fuel-induced warming was early on after analyzing samples of very long-lived sponges (Ceratoporella nicolsoni) forms a calcium carbonate skeleton.

The 10-centimeter-wide corpora cavernosa could be about 400 years old, team members say amos winter at Indiana State University. “These sponges grow very slowly.”

The sponges were collected by divers at depths of 33 to 91 meters off the coast of Puerto Rico. Although the original goal was to study the ocean's pH in the past, the researchers also measured the ratio of strontium to calcium, which varied with water temperature when calcium carbonate was formed.

Researchers noticed a close correlation between temperatures “recorded” by sponges and the average surface temperature of the Earth measured by instruments, especially after 1960, when measurements became more reliable. That means there is.

“This is kind of a serendipitous discovery, but the connection is very strong,” McCulloch says. “They are changing proportionately to the world average. The main differences occur when instrumental records are the poorest.”

The researchers therefore calculated the average global temperature before the industrial revolution back to 1,700 degrees Celsius, assuming that the sponges accurately reflected this.

The researchers believe their study should be taken into account when assessing whether the IPCC has exceeded the 1.5°C limit. “The bottom line is yes, the IPCC should take this issue seriously,” McCulloch said.

He also thinks climate modelers need to take the findings into account. If previous carbon emissions are causing more warming than thought, the impact of further emissions may be underestimated, he says.

But other climate scientists are far from convinced. “In my view, it would be imprudent to claim that an instrumental record is wrong based on paleocavernoids from one region of the world,” he says. michael man at the University of Pennsylvania. “That doesn't make sense to me. That said, our own early research supports the idea that there was at least another 0.2 degrees Celsius of warming by the late 19th century.”

In fact, anthropogenic warming may have started thousands of years ago. According to the early Anthropocene hypothesis proposed by William Ruddiman The University of Virginia announced that the first farmers' clearing of forests and creation of rice paddies produced enough carbon dioxide and methane to stop the planet from cooling and entering a new ice age.

Recent studies by other researchers have provided increasing evidence to support this hypothesis, but it is still far from being widely accepted.

topic:

Source: www.newscientist.com