In mid-February, a remarkably early, record-breaking heat wave hit the southern part of West Africa. Climate change made this extreme heat ten times more likely, according to a new analysis by an international team of scientists. It also pushed the heat index about four degrees Celsius higher than it would have been without the extra greenhouse gases in the atmosphere from burning fossil fuels.

Officials saw the unusual temperatures coming and national weather agencies in Ghana and Nigeria warned the public. The Africa Cup of Nations football tournament took place in Ivory Coast during the heat wave and players had to take extra breaks during the matches to hydrate.

What was particularly striking about this heat wave was the onset of high temperatures so early in the year, when people had less time to adapt to rising temperatures. “Many, many people would not have acclimatized to the heat,” said Wasiu Adeniyi Ibrahim, head of the Nigerian Meteorological Agency’s central forecast office and author of the study.

During the heat wave, humidity increased the danger. During the worst of the event, temperatures rose above 40 degrees Celsius, or 104 degrees Fahrenheit. But the high humidity made the air feel even hotter. The heat index, which measures the combined effect of heat and humidity on the human body, rose to about 50 degrees Celsius or 122 degrees Fahrenheit.

Researchers have limited data on how this heat has affected people more broadly in West Africa, and whether it has led to many hospitalizations and deaths. But there is reason to believe there may be widespread damage, said Maja Vahlberg, a risk advisor at the Red Cross Red Crescent Climate Center and one of the authors of the analysis.

Many residents of the region do not have adequate access to water, energy and sanitation. That means that during heat waves, people have “very limited options for individual coping strategies, such as using air conditioning and drinking or showering more often,” Ms. Vahlberg said. About half of the region’s urban population lives in informal housing, including houses built with sheet steel, which retains heat.

The elderly, people with existing illnesses and outdoor workers are especially vulnerable to extreme heat.

The analysis, conducted by a group known as World Weather Attribution, took longer than similar studies the group’s scientists have conducted on other extreme weather events. West Africa has less data from weather stations than other parts of the world, making studies linking weather there to climate change more difficult to conduct. But last month’s extreme heat was an early sign, before spring had even started, of what would happen this summer in this region and across the Northern Hemisphere.

South Sudan has long been affected by disasters exacerbated by climate change, such as recurring droughts and floods. Now extreme heat is forcing the world’s youngest country to close its schools.

Authorities have ordered schools across the country closed since Monday due to a wave of excessive heat that is expected to last at least two weeks. Temperatures are forecast to reach 113 degrees Fahrenheit, well above the 90 degree highs typically experienced in the dry season from December to March.

Officials did not say how long schools would remain closed. But the ministries of health and education said in a joint statement that “any school opened during this period will have its registration revoked.”

Parents have also been urged not to let their children play outside and to monitor them for signs of heat exhaustion and heatstroke.

Sweltering temperatures in South Sudan, where the tropical climate has both dry and wet seasons, interrupt the start of the academic year. Most schools in the East African country, especially those outside the capital Juba, are overcrowded and underfunded and lack infrastructure such as air conditioning to help withstand such heat.

South Sudan is highly exposed to severe climatic events, including droughts, floods and rising temperatures. These changes have exacerbated displacement, food insecurity and communal conflict in the country of 11 million people, which gained independence from Sudan in 2011.

The heat wave is also expected to put pressure on the country’s nascent healthcare system, which has long struggled with limited funding and labor shortages.

South Sudan is not the only African country where extreme weather conditions have led to school closures. In 2022, the Malawi government shortened the school day in the southern Shire Valley due to rising temperatures. And in Uganda, severe flooding has repeatedly forced the government to do so schools close over the years.

But in South Sudan, conflict, a worsening humanitarian crisis and a tense political environment have made it even more difficult to alleviate the unrest caused by climate change.

South Sudan’s civil war has killed around 400,000 people and displaced millions more since 2013. And while there has been a tenuous political settlement among the country’s feuding leaders in recent years, there is a growing humanitarian crisis and deadly divisions between forces within the ruling power. alliance have increased uncertainty over whether repeatedly postponed elections will take place this year.

At the same time, war in neighboring Sudan has forced the return of nearly half a million South Sudanese who fled the conflict at home. Many have returned to towns and villages where their homes and farms have been looted and are finding it difficult to rebuild their lives.

Emmanuel Lokosang, head teacher at Jada Jedid Nursery and Primary School in the capital, said he hoped the weather would cool soon so students could resume classes.

“Juba is really hot,” Mr. Lokosang, whose school has more than 600 students, said in a telephone interview Wednesday morning.

He added: “We hope they do not delay for long because the more we delay, the more it will affect the academic calendar and how we can restore the curriculum.”

It may have been a warmer than normal winter in Maine, but that doesn’t mean it didn’t get extremely cold. In mid-January, temperatures in Farmingdale, a town outside Augusta where Kaylie McLaughlin lives, dropped to 6 degrees Fahrenheit. “The kind of cold that hurts,” she said.

But this winter, Mrs. McLaughlin’s bungalow is nice and warm, thanks to two heat pumps she installed to replace her oil furnace. “I just feel so comfortable,” said Ms. McLaughlin, a pharmaceutical sales representative. She also saves money and no longer pays $400 for an oil delivery every four weeks.

Unlike a space heater, a heat pump extracts heat from the outside air, even in freezing temperatures, and then runs it through a compressor, making it even hotter, before pumping it indoors. In summer it can work in reverse, taking heat from inside a building and pumping it outside, cooling interior spaces.

Heat pumps in 2023 sold out gas ovens a climate victory in the United States for the second year in a row. Electric heat pumps are the cheapest and most energy-efficient ways to heat and cool homes, and they don’t emit the carbon pollution that overheats the planet.

No state has adopted them faster than Maine.

This northeastern town with hardy species and snowbound winters is going electric quickly and installing electric heat pumps three times faster than the national average, according to Rewiring America, a nonprofit that promotes widespread adoption of electricity. Last September, Maine met its goal of installing 100,000 heat pumps in households two years ahead of scheduleand aims to install another 175,000 by 2027.

Rapid adoption in Maine is being driven by a combination of state rebates on top of federal incentives and a new cadre of vendors and installers, as well as growing frustrations over the high cost of heating oil.

The $12,000 price tag for Ms. McLaughlin’s heat pumps was cut in half by state rebates, and she paid the rest with low-interest financing. In the coldest months, her loan payments and electric bills were the same as her old oil bill, but she has already saved $100 a month during the shoulder season and received a $2,000 federal tax credit. Plus, the heat is reliable, she said, unlike her rickety old oil furnace, which forced her to spend much of the winter indoors. And even though she sets the pumps to 66 degrees, she says it feels better because the heat is distributed more evenly throughout her home.

It’s a big conversion for a state where more than half of households burned oil for heat in 2022, the highest rate in the country.

The change marks a cultural shift, helped along when then-Governor Paul LePage, a conservative Republican, installed heat pumps in both his official residence and his waterfront home a decade ago. Word of mouth spread among families, neighbors and even church communities where new heat pumps kept congregants warm. Even in frigid temperatures, they told each other, heat pumps worked even in Maine.

“Ten years ago they weren’t really popular,” says Josh Tucker of Valley Home Services, a family-owned heating business outside Bangor. “No one really knew what they were.” He first installed heat pumps in his sister’s new home in 2014, despite the objections of her contractor who, Mr. Tucker said, was “very against it.”

“He thought she would freeze to death if she didn’t have a furnace or a boiler,” he said. She did not do that and uses the same heat pumps today.

The new technology was especially quickly embraced in a northern Maine community after Mr. Tucker’s father installed heat pumps in a Methodist church there. The Tucker family still sells heating oil and propane, but less and less. The heat pump business, meanwhile, grew from installing two to three units per week to 3,000 last year, an almost twenty-fold increase.

“We’ve done TV ads and social media ads, but the biggest thing has always been word of mouth and that’s how it’s exploded,” Mr Tucker said.

According to Efficiency Maine, an independent agency that implements energy efficiency programs, replacing heating oil and propane with heat pumps saves a household above a thousand dollars a year.

They can also make a dent in the pollution that causes climate change. By means of a calculation, If every family home in the United States used heat pumps, annual greenhouse gas emissions would drop by 160 million metric tons, the same as taking 32 million cars off the road.

Heat pumps perform a kind of magic trick. They can produce three to four units of heat with one unit of energy input.

Because nothing is burned, the air quality in the area improves. Because heat pumps do not use oil or propane, there are no fuel leaks. Heat pumps run on electricity, and in Maine, much of that electricity comes from wind and other clean sources. In 2022, 64 percent of the electricity generated in Maine came from renewable energy.

In a twist, the state’s rapid adoption of electric heat pumps is tied to its historic reliance on oil and propane for heat. Maine is rural and sparsely populated, and gas companies concluded it wasn’t worth building distribution lines in many parts of the state, said Michael Stoddard, the executive director of Efficiency Maine. Instead of getting heating fuel from a utility company, Mainers typically have to pick up the phone to arrange a delivery when they’re running low.

This was one reason why Michelle Whitmore, 60, a former monogrammer at LL Bean, signed up for a pilot program that installed a free heat pump in her mobile home two years ago. Ms Whitmore is legally blind and relied on a neighbor to read her fuel gauge. She was also tired of having to shovel snow so the fuel deliverers could reach her oil tank.

“I thought it couldn’t be colder with the heat pump than my furnace,” she said. Now all she has to do is press a switch. The heating and cooling are also more consistent, she said, and although her electric bill has increased, she still saves $200 to $300 a year.

There is resistance from the oil and gas industry, which has provided support campaigns fighting electrification and questioning the effectiveness of heat pumps in the bitter cold. “Heat pumps have become involved in the culture war of electrification versus sticking to fossil fuels,” said Christopher Kessler, a state representative from South Portland who works as an energy auditor. Mr Kessler said some home heating companies that sell both oil and heat pumps still incorrectly claim that heat pumps cannot be used as a primary heating source.

Mr. Stoddard of Efficiency Maine said that while many Mainers use heat pumps in conjunction with oil and gas heating systems, the hybrid approach reduces the effectiveness of the heat pump. His agency recently changed its program so that only households that switched completely to heat pumps would receive state rebates. People can still use fossil fuel heating systems, but only as a backup or for hot water in the home, he said.

Smokey Bunn said he and his family paid up to $600 a month for oil, and used three tons of wood pellets for their heating stove every winter. “It works great,” he said of the family’s new heat pumps. “People who make them enthusiastic.”

The household’s biggest fans, he said, may be the family’s two dogs, Ivan and Nahla, who regularly curl up on the couch in front of the system. “It pushes hot air towards them,” he said. “They love it.”

The exceptional warmth that first enveloped the planet last summer will continue strongly until 2024: last month was the warmest January on record, the European Union's climate monitor announced on Thursday.

It was also the warmest January on record for the oceans, according to the European Union's Copernicus Climate Change Service. The sea surface temperature was slightly lower than August 2023, the hottest month on record. And sea temperatures continued to rise in the first few days of February, surpassing daily records set last August.

The oceans absorb most of the extra heat that greenhouse gases trap in the atmosphere near the Earth's surface, making them a reliable indicator of how much and how quickly we are warming the planet. Warmer oceans provide more fuel for hurricanes and… atmospheric river storms and can disrupt marine life.

January sees average air temperatures, both on the continents and in the seas, surpassing all previous records for the time of year for eight months in a row. Overall, 2023 was the hottest year on Earth in more than a century and a half.

The main cause of all this heat is no mystery to scientists: Fossil fuel burning, deforestation and other human activities have been steadily pushing the mercury up for more than a century. The current El Niño weather cycle also releases more ocean heat into the atmosphere.

But exactly why Earth has been so hot for so long in recent months remains a matter of debate among researcherswho are waiting for more data to come in to see if other, less predictable and perhaps less understood factors might also be at work at the margins.

“Rapid reductions in greenhouse gas emissions are the only way to stop the rise in global temperatures,” Samantha Burgess, deputy director of Copernicus, said in a statement.

According to Copernicus data, January temperatures were well above average in eastern Canada, northwest Africa, the Middle East and Central Asia, although much of the interior United States was colder than normal. Parts of South America were warmer than normal and dry, contributing to the recent wildfires devastated central Chile.

The intensity of recent underwater heat waves prompted the National Oceanic and Atmospheric Administration in December to add three new levels to its system of ocean heat warnings to indicate where corals may be bleaching or dying.

An El Niño pattern like the one currently observed in the Pacific Ocean is associated with warmer years for the planet, as well as a range of effects on rainfall and temperatures in specific regions.

But as humans warm the planet, the effects that forecasters could once confidently expect from El Niño on local temperatures are no longer as predictable, says Michelle L'Heureux, a NOAA scientist who studies El Niño and its opposite phase, La Niña. , studies.

“In regions where temperatures used to be below average during El Niño, you almost never see that anymore,” says Ms. L'Heureux. “You see something that is closer to average, or even above average.”