heatwaves

The climate is changing so fast that we haven’t seen how bad extreme weather could get

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Andreas Thaller/Alamy Stock Photo

Simon H. Lee, University of St Andrews; Hayley J. Fowler, Newcastle University, and Paul Davies, Newcastle University

Extreme weather is by definition rare on our planet. Ferocious storms, searing heatwaves and biting cold snaps illustrate what the climate is capable of at its worst. However, since Earth’s climate is rapidly warming, predominantly due to fossil fuel burning, the range of possible weather conditions, including extremes, is changing.

Scientists define “climate” as the distribution of possible weather events observed over a length of time, such as the range of temperatures, rainfall totals or hours of sunshine. From this they construct statistical measures, such as the average (or normal) temperature. Weather varies on several timescales – from seconds to decades – so the longer the period over which the climate is analysed, the more accurately these analyses capture the infinite range of possible configurations of the atmosphere.

Typically, meteorologists and climate scientists use a 30-year period to represent the climate, which is updated every ten years. The most recent climate period is 1991-2020. The difference between each successive 30-year climate period serves as a very literal record of climate change.

This way of thinking about the climate falls short when the climate itself is rapidly changing. Global average temperatures have increased at around 0.2°C per decade over the past 30 years, meaning that the global climate of 1991 was around 0.6°C cooler than that in 2020 (when accounting for other year-to-year fluctuations), and even more so than the present day.

A moving target for climate modellers

If the climate is a range of possible weather events, then this rapid change has two implications. First, it means that part of the distribution of weather events comprising a 30-year climate period occurred in a very different background global climate: for example, northerly winds in the 1990s were much colder than those in the 2020s in north-west Europe, thanks to the Arctic warming nearly four times faster than the global average. Statistics from three decades ago no longer represent what is possible in the present day.

Second, the rapidly changing climate means we have not necessarily experienced the extremes that modern-day atmospheric and oceanic warmth can produce. In a stable climate, scientists would have multiple decades for the atmosphere to get into its various configurations and drive extreme events, such as heatwaves, floods or droughts. We could then use these observations to build up an understanding of what the climate is capable of. But in our rapidly changing climate, we effectively have only a few years – not enough to experience everything the climate has to offer.

Extreme weather, such as drought, is a particular problem for farmers. EPA-EFE/Guillaume Horcajuelo

Extreme weather events require what meteorologists might call a “perfect storm”. For example, extreme heat in the UK typically requires the northward movement of an air mass from Africa combined with clear skies, dry soils and a stable atmosphere to prevent thunderstorms forming which tend to dissipate heat.

Such “perfect” conditions are intrinsically unlikely, and many years can pass without them occurring – all while the climate continues to change in the background. Based on an understanding of observations alone, this can leave us woefully underprepared for what the climate can now do, should the right weather conditions all come together at once.

Startling recent examples include the extreme heatwave in the Pacific north-west of North America in 2021, in which temperatures exceeded the previous Canadian record maximum by 4.6°C. Another is the occurrence of 40°C in the UK in summer 2022, which exceeded the previous UK record maximum set only three years earlier by 1.6°C. This is part of the reason why the true impact of a fixed amount of global warming is only evident after several decades, but of course – since the climate is changing rapidly – we cannot use this method anymore.

Playing with fire

To better understand these extremes, scientists can use ensembles: many runs of the same weather or climate model that each slightly differ to show a range of plausible outcomes. Ensembles are routinely used in weather prediction, but can also be used to assess extreme events which could happen even if they do not actually happen at the time.

When 40°C first appeared in ensemble forecasts for the UK before the July 2022 heatwave, it revealed the kind of extreme weather that is possible in the current climate. Even if it had not come to fruition, its mere appearance in the models showed that the previously unthinkable was now possible. In the event, several naturally occurring atmospheric factors combined with background climate warming to generate the record-shattering heat on July 19 that year.

The highest observed temperature each year in the UK, from 1900 to 2023

A graph showing the highest observed temperature in the UK between 1900 and 2023.
The hottest days are getting hotter in the UK. Met Office/Kendon et al. 2024

Later in summer 2022, after the first occurrence of 40°C, some ensemble weather forecasts for the UK showed a situation in which 40°C could be reached on multiple consecutive days. This would have posed an unprecedented threat to public health and infrastructure in the UK. Unlike the previous month, this event did not come to pass, and was quickly forgotten – but it shouldn’t have been.

It is not certain whether these model simulations correctly represent the processes involved in producing extreme heat. Even so, we must heed the warning signs.

Despite a record-warm planet, summer 2024 in the UK has been relatively cool so far. The past two years have seen global temperatures far above anything previously observed, and so potential extremes have probably shifted even further from what we have so far experienced.

Just as was the case in August 2022, we’ve got away with it for now – but we might not be so lucky next time.

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Simon H. Lee, Lecturer in Atmospheric Science, University of St Andrews; Hayley J. Fowler, Professor of Climate Change Impacts, Newcastle University, and Paul Davies, Chief Meteorologist, Met Office and Visiting Professor, Newcastle University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Continue ReadingThe climate is changing so fast that we haven’t seen how bad extreme weather could get

Thousands Evacuated Amid Northern California Wildfire and Heatwave

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Original article by BRETT WILKINS republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).

Law enforcement officers watch as the Thompson Fire burns over Lake Oroville in Oroville, California on July 2, 2024.  (Photo: Josh Edelson/AFP via Getty Images)

“It cannot be stressed enough that this is an exceptionally dangerous and lethal situation,” the National Weather Service warned.

California Gov. Gavin Newsom on Wednesday declared a state of emergency in a northern county where a major wildfire has burned thousands of acres and forced the evacuation of thousands of residents amid near-record heat throughout much of the Golden State fueled by human-caused global heating.

The California Department of Forestry and Fire Protection (CAL FIRE) said shortly after noon local time Wednesday that the Thompson Fire, which began Tuesday morning in Butte County, had burned 3,568 acres with no containment in and around the city of Oroville, home to more than 20,000 people.

Citing an “imminent threat to life,” Newsom, a Democrat, issued an emergency declaration and said that “we are using every available tool to tackle this fire and will continue to work closely with our local and federal partners to support impacted communities.”

CAL FIRE said that more than 1,400 firefighters using 199 engines, 46 dozers, eight helicopters, and other equipment are battling the blaze. More than 28,000 Oroville area residents have been evacuated.

Red flag conditions are being exacerbated by low humidity and near-record temperatures throughout California. Oroville is expected to hit a high of 110°F on Wednesday, with daytime highs forecast to remain in the 110s through the holiday weekend. Dozens of daily, monthly, and all-time records could be broken throughout the state.

“It cannot be stressed enough that this is an exceptionally dangerous and lethal situation,” the National Weather Service’s (NWS) San Francisco Bay Area branch cautioned as it extended the red flag warning through Friday while preparing the public for the possibility of further extensions.

Daniel Swain, a climate scientist at the University of California, Los Angeles, said during a video briefing, “I’m not so sure that really any of us will have seen this many days at this sustained level of heat, both daytime and most importantly nighttime heat.”

Commenting on the wildfire and heatwave, Fossil Free Media director Jamie Henn said on social media that “we need the California Legislature to pass their climate superfund bill NOW to #MakePollutersPay for these fossil-fueled disasters.”

Introduced in April by California state Sen. Caroline Menjivar (D-20) but shelved the following month, S.B. 1497—the Polluters Pay Climate Cost Recovery Act—would require major fossil fuel producers to pay for their historic carbon emissions.

The NWS said that as of Wednesday, more than 110 million people across the United States were facing either a heat advisory, watch, or warning. So far, 2024 has been the hottest year on record. Climate Central, a nonprofit news organization focusing on the worsening planetary emergency, said climate change has made the current California heatwave at least five times likelier.

Original article by BRETT WILKINS republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).

Continue ReadingThousands Evacuated Amid Northern California Wildfire and Heatwave

Rate of Global Warming Reaches All-Time High, Report Shows

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Original article by EDWARD CARVER republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).

Firefighters set a backfire to protect homes during a wildfire in California in September 2020.  (Photo: David McNew/Getty Images)

“The devastation wrought by wildfires, drought, flooding, and heatwaves the world saw in 2023 must not become the new normal,” the report’s author said.

Climate scientists published a report Wednesday showing that the rate of global warming reached an all-time high in the 10 years up to and including 2023 and that the record-breaking heat of last year was primarily due to that human-caused heating rather than other factors such as El Niño.

The scientists found that from 2014 to 2023, the Earth warmed 0.26°C—higher than any previous 10-year period. The report, published in Earth System Science Data, was completed by 57 scientists who used the methods of the United Nations Intergovernmental Panel on Climate Change (IPCC), which produces major reports only every five to 10 years, with the next one expected in 2027. The report authors sought to fill the gap and, at least in one case, to galvanize climate action.

“Rapidly reducing emissions of greenhouse gases towards net zero will limit the level of global warming we ultimately experience. At the same time, we need to build more resilient societies,” lead author Piers Forster, a climate physicist at the University of Leeds in the U.K. and an IPCC author, said in a statement. “The devastation wrought by wildfires, drought, flooding, and heatwaves the world saw in 2023 must not become the new normal.”

Over the course of 2023, temperatures were on average 1.43°C above preindustrial levels, Forster and co-authors found, with an estimated 1.31°C of that due to human-caused global warming, and the relatively small remainder due to variability from events such as El Niño and La Niña.

The report also shows that the Earth’s remaining “carbon budget”—how much can be emitted before reaching 1.5°C of warming, the Paris agreement target—is now roughly 200 gigatonnes, which will take only five years or so for the global population to use. This is down from the 500 gigatonnes that the IPCC estimated remained in the budget as of 2020.

Adam Vaughan, environment editor at The Times, a U.K. newspaper, drew attention to the short time period in which humanity has to act, writing on social media that the 1.5°C target could be “blown” if emissions didn’t go down.

In a guest post in Carbon Brief, Forster and another co-author explained that their report was “nothing short of alarming, yet it does contain some encouraging news.”

“Greenhouse gas emissions have not yet risen beyond pre-pandemic levels and there is evidence that the rate of increase in CO2 emissions over the past decade has slowed compared to the 2000s,” they said.

Forster, who also led the annual report in its first iteration last year, spoke to reporters in such a way as to avoid doomsday rhetoric.

“If you look at this world accelerating or going through a big tipping point, things aren’t doing that,” he told TheAssociated Press. “Things are increasing in temperature and getting worse in sort of exactly the way we predicted.”

However, the climate news remains dire: Researchers working with even more up-to-date data—through May—have found that the average temperature increase above preindustrial levels is now 1.6°C, and each of the last 12 months has been the hottest on record for that month. Those findings are from data released by the European Union’s Copernicus Climate Change Service and reported by The Washington Post.

Original article by EDWARD CARVER republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).

Continue ReadingRate of Global Warming Reaches All-Time High, Report Shows

2023 Destroys Global Heat Record as Fossil Fuel Emissions Boil the Planet

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Original article by JAKE JOHNSON republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).

Indonesian firefighters work to extinguish a wildfire in Ogan Ilir, Indonesia on September 14, 2023.  (Photo: Muhammad A.F/Anadolu Agency via Getty Images)

“How many more records does it take before we phase out fossil fuels and deal with it?” asked one climate campaigner.

European scientists officially confirmed Tuesday that 2023 was the hottest year on record, surpassing 2016 by a huge margin as greenhouse gas emissions from fossil fuels continue to drive global temperatures to terrifying new highs.

The conclusion from the European Union’s Copernicus Climate Change Service was hardly unexpected given the unparalleled heatwaves that gripped large swaths of the planet last year, ushering in what the head of the United Nations called “the era of global boiling.”

Last year’s global average temperature was 14.98°C, 0.17°C warmer than 2016, 0.60°C warmer than the 1991-2020 average, and 1.48°C warmer than the 1850-1900 pre-industrial level, according to Copernicus.

“2023 was an exceptional year with climate records tumbling like dominoes,” said Copernicus deputy director Samantha Burgess. “Not only is 2023 the warmest year on record, it is also the first year with all days over 1°C warmer than the pre-industrial period. Temperatures during 2023 likely exceed those of any period in at least the last 100,000 years.”

Liz Bentley, chief executive of the U.K.’s Royal Meteorological Society told CNN on Tuesday that after last year’s record-shattering summer, scientists predicted that global warming would reach around 1.3°C above pre-industrial levels.

That projection, Bentley said, has been “annihilated” by the new Copernicus data, which shows that planetary warming is perilously close to the Paris accord’s 1.5°C target.

“If you look at climate projections, when we expect to see temperature changes of close to 1.5°C, indeed it has come sooner than many would have expected,” Bentley added. “We’ve definitely seen an acceleration towards that, rather than it being a kind of linear progression. It feels like it’s rising much more exponentially.”

Scientists expect 2024 to be even hotter than last year, raising the stakes for badly lagging global efforts to rein in planet-warming fossil fuel production, which in 2023 hit record levels in the United States—the largest historical contributor to greenhouse gas emissions.

“How many more records does it take before we phase out fossil fuels and deal with it?” asked climate campaigner Mike Hudema.

Copernicus director Carlo Buontempo said in a statement Tuesday that “the extremes we have observed over the last few months provide a dramatic testimony of how far we now are from the climate in which our civilization developed.”

“This has profound consequences for the Paris Agreement and all human endeavors,” said Buontempo. “If we want to successfully manage our climate risk portfolio, we need to urgently decarbonize our economy whilst using climate data and knowledge to prepare for the future.”

Original article by JAKE JOHNSON republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).

Continue Reading2023 Destroys Global Heat Record as Fossil Fuel Emissions Boil the Planet

‘Five-Alarm Fire’ as Global Temps Breach 2°C Threshold

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Canadian wildfire 2023
Canadian wildfire 2023

Original article by OLIVIA ROSANE republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0). 

While scientists were quick to point out that this was just a daily anomaly, not a permanent shift, it is a “canary in the coalmine” that “underscores the urgency of tackling greenhouse gas emissions.”

Global temperatures surpassed 2°C above preindustrial levels for the first time Friday, according to preliminary data from the European Union’s Copernicus Climate Change Service.

The European Centre for Medium-Range Weather Forecasts’ ERA5 data set showed global service air temperatures rising 2.07°C above the 1850-1900 average on Friday and 2.06°C above that average on Saturday, the service said.

“This is a five-alarm fire for humanity,” the group Climate Defiance tweeted in response to the figures.

In the 2015 Paris agreement, world leaders set out to keep warming to “well-below” 2°C above preindustrial levels. Allowing warming to breach that point increases several climate risks, according to the Intergovernmental Panel on Climate Change (IPCC): 2°C of warming compared with 1.5°C would raise sea levels by an additional 0.1 meters by 2100, destroy 99% of coral reefs instead of 70% to 90%, and expose several hundred million more people to poverty and climate-related hazards by 2050.

Friday’s 2°C breach was first noted by Copernicus Climate Change Service deputy director Samantha Burgess on social media Sunday. She said the day was also 1.17°C above the 1991-2020 average, making it the warmest November 17 on record.

Scientists were quick to point out that this doesn’t mean global heating has breached the 2°C threshold long-term.

“The 1.5°C and 2°C warming thresholds have been defined in terms of the trend line,” University of Pennsylvania climate scientist Michael Mann tweeted. “Not individual years, let alone months, weeks, or days (the shorter the time period, the larger the random fluctuations). Those who imply otherwise are misleading you.”

Richard Allan, professor of climate science at the University of Reading in the U.K., told CNN that it was “entirely expected that single days will surpass 2°C above preindustrial well before the actual 2°C target is breached over many years.”

“We are blowing past warning signs with wild abandon. We are approaching the precipice and flooring the gas.”

That said, the reading was a “canary in the coalmine” that “underscores the urgency of tackling greenhouse gas emissions,” Allan said.

It also comes in a year of dropping canaries: The 12 months from November 2022 to October 2023 were the 12 hottest on record, according to a Climate Central analysis. 2023 saw the hottest Northern Hemisphere summer on record, the hottest month in July, and is likely to be the hottest year not just since record-keeping began, but in the last 125,000 years. And it’s not just numbers. The record-breaking temperatures fueled deadly heatwaves, wildfires, and floods around the world.

“The indicators are flashing red,” Climate Defiance wrote. “The planet’s vital signs are clear. Humanity is on life support. With the El Niño cycle just beginning, this 2°C breach sadly represents not a climax but a small taste of what is to come.”

“This is happening faster than expected,” the group continued. “We are blowing past warning signs with wild abandon. We are approaching the precipice and flooring the gas. This is madness. Utter madness.”

The 2°C breach comes a little less than two weeks from the start of the next United Nations Climate Change Conference in the United Arab Emirates. A recent report from U.N. Climate Change found that national plans were still incompatible with limiting warming to 1.5°C and that world leaders must take “bold strides forward” at the conference “to get on track.” More than 650 scientists have signed a letter to President Joe Biden urging him to back a fossil-fuel phaseout at the talks.

“It’s just one day (so far) above 2°C, but it highlights again that the world is approaching the limits set out by the Paris Agreement,” IPCC scientist Ed Hawkins tweeted. “We already have many of the solutions to rapidly reduce emissions and halt the rise in global temperatures. We just need to choose to use them.”

Original article by OLIVIA ROSANE republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0). 

Continue Reading‘Five-Alarm Fire’ as Global Temps Breach 2°C Threshold