Climate, in brief

Tropical Storm Isaias formed early on Wednesday in the warm water off eastern Mexico, the US National Hurricane Center said. [1]

Forecasters expect it to become a hurricane by Thursday morning, and to strengthen further, to category 2, by Friday morning. [2]

A storm counts as a hurricane once its winds reach 74 miles an hour. Isaias had winds of about 45 miles an hour on Wednesday. [3]

If it becomes a hurricane, it will be the latest first hurricane of an Atlantic season since reliable records began, Scientific American reported. [3]

Isaias is the ninth tropical storm of the Atlantic season, and the first expected to become a hurricane. [2]

The season has been quiet because of a strong El Nino, a warming of the Pacific Ocean that creates high winds over the Atlantic. Those winds tear storms apart before they can grow. [2][3]

Isaias formed where those winds are weak and the sea is 30 to 31C, which gives a storm the heat it feeds on. [2]

The center of the storm could come ashore late Friday or early Saturday, somewhere between eastern Louisiana and the western Florida Panhandle. Hurricane and storm surge watches are in place there. [1][2]

Three to six inches of rain could fall along the coast, and up to ten in some places, with a risk of flash floods in towns. [2]

Mexico's Yucatan Peninsula and the Bay of Campeche could see about 4 inches of rain first, as the storm passes out at sea. [2]

Many Americans live in mobile homes. In first-ever wind tests at Florida International University, 110 mile-an-hour winds sheared the screws on one and rolled it over twice. [4]

Saturday's big college football game between Georgia and Alabama, which President Trump plans to attend, may be moved. One other game was already moved to Friday. [5]

Why it matters. Watch where Isaias comes ashore late Friday or early Saturday, and whether the stronger winds it meets on its way north hold its strength down, as forecasters expect. [2][1]

Members of the International Energy Agency (IEA), the group that coordinates rich countries' emergency oil, agreed on Wednesday to speed up the release of their stocks and to put diesel first. [7] Of 400 million barrels promised in March, after the Iran war began, 325 million have been released. [17] Last week the G7, seven rich democracies, promised President Trump 100 million barrels after US officials threatened to stop exporting diesel. [17] France and Germany now say those barrels are the rest of the March promise, not new ones. [18]

Why it matters. European drivers and truckers get no extra diesel beyond what was already pledged in March. [18] EU countries say they will release more only after the IEA says it is safe for their own supply. [17]

Heating oil is forecast to average $5.26 a gallon in the US this winter, 34% more than last year, the US Energy Information Administration said on Tuesday. [8] Heating oil and diesel are generally the same product, and damage to refineries in Russia and the Middle East has made both scarce. [8] More than 4 million US households heat with oil, and about 82% of the homes that burn it are in the Northeast. [19] Massachusetts declared a state of emergency on Monday. [19]

Why it matters. A home heated with oil is expected to spend about $2,115 from November to March. [8] The federal help for poor families' heating bills now buys much less fuel, and the US Congress is weighing whether to add billions. [19]

Zavodovski, a volcanic island near Antarctica, had 63% fewer chinstrap penguin nests in 2025 than in 2011, a British Antarctic Survey study found. [12] In 2011 it held about 600,000 chinstraps and 90,000 macaroni penguins, the biggest penguin colony anywhere. [20] The team sailed for 15 days to reach it and used drones and tracking tags. [12] As the sea warms, the krill the chinstraps eat have moved south, where sea ice blocks the birds. [21]

Why it matters. The scientists say the chinstrap may now need to be listed as endangered. [20] Macaroni penguins, which eat fish as well as krill, grew by 28% from 2011 to 2016 and have held steady since. [21]

A study in Nature read 1,000 years of mud from Purghagoolah, a lake in Croajingolong National Park in south-east Australia. [22] Pollen in it shows open woodland with about 10% tree cover for 800 years, while the GunaiKurnai people burned the land gently. [23] Settlers forced them off between 1830 and 1860, and the burning stopped. [23] Shrubs moved in, fires got hotter, and tree cover rose to about 40%. [23]

Why it matters. Fire seasons in the park have shrunk from about 40 years apart in the late 1800s to about five years in the last decade. [24] The study's lead author, Michael-Shawn Fletcher, says it supports bringing back cultural burning, which uses cool fires at the right time and place. [22]

Flavio Bolsonaro won 47% in the first round of Brazil's presidential election, against 44.2% for President Luiz Inacio Lula da Silva, about 56.1 million votes to 53.8 million. [25][26] The two meet again in a runoff on 25 October. [25] Flavio is the son of Jair Bolsonaro, the former president, under whom Amazon forest clearing rose about 60%. [27] Under Lula clearing has fallen 45%, to its lowest level in more than a decade. [27]

Why it matters. Brazil holds about 60% of the Amazon, the world's largest rainforest. [27] Flavio has promised to end illegal clearing by 2029, but as a lawmaker he backed a bill to scrap a rule that makes Amazon landowners keep some native forest. [27][25]

On Monday President Trump let road vehicles use red-dyed diesel, the same fuel sold untaxed for farms and building sites. [28] The 24.4-cent federal tax is only put off until the end of the year, not removed. [28] Gilbert Metcalf, a former US Treasury official, says it adds no diesel, since US refineries are already running near their limit. [28] He says moving farm diesel onto the roads would make it dearer for farmers. [28]

Why it matters. US diesel averaged $6.20 a gallon on 5 October, nearly $2.50 more than a year ago, in the middle of harvest. [9] Oil refiners now want a cut to the rule that makes them blend crop-based fuel into diesel, and farm groups oppose it. [29]

Mike Wirth, the chief executive of Chevron, one of the biggest US oil companies, said a US ban on diesel exports would be unwise. [30] He told CNBC it would make allies doubt that the US will supply them when times are hard. [30] The Trump administration had threatened the ban to push Europe to release its diesel stocks. [17] Saudi Aramco's chief says rebuilding the world's oil stocks could take two years. [30]

Why it matters. Wirth said the US has been a reliable supplier to the world when it is needed, and that there are other options. [30] President Trump said last week the US was never going to ban exports. [28]

Indigenous and local groups in Indonesian Borneo have sued Indonesia's government for gross negligence over this year's forest fires. [11] The 10 defendants include President Prabowo Subianto and the governor of West Kalimantan. [11] None came to the first hearing in Pontianak on Wednesday, so judges adjourned it to 21 October. [11] The fires are often lit to clear land for oil palm, and a strong El Nino has dried the forests. [11]

Why it matters. The smoke has closed schools in Malaysia and reached Singapore, Brunei and the Philippines. [11] The plaintiffs want the state to pay for residents' health care and repair the land. [11]

After Australia's High Court struck down the Mount Pleasant coal mine expansion on Wednesday, a Greens state MP in New South Wales said lawyers should go to court against other approvals. [31] Sue Higginson said the ruling could cause legal trouble for the Hunter Valley Operations extension, the state's biggest, approved a week earlier. [31] The judges said planners had failed to consider limiting emissions from coal burned overseas. [32] Prime Minister Anthony Albanese had said in May that he hoped the community group would lose. [33]

Why it matters. Wendy Wales and Tony Lonergan, retired teachers who live next to the mine, fought it for more than four years. [32] The ruling sets a precedent for fossil fuel projects across New South Wales. [31]

India got its lowest rainfall in more than a decade between June and September, which CNBC links to El Nino. [10] El Nino is a warming of the Pacific that can change weather around the world. [3] India's foreign minister has warned that El Nino and fertiliser shortages caused by wars will bring a major food crisis in the coming months. [10] India's farms feed almost 1.5 billion people and employ 46.1% of its workers. [10]

Why it matters. A poor harvest would raise food prices and slow spending in India's countryside. [10] India is one of the world's top exporters of rice and sugar, so buyers abroad would feel it too. [10]

Nepal is preparing to amend two laws so families can register the deaths of 5,285 people still missing after the 26 August floods. [34] The floods along the Bhotekoshi and Trishuli rivers killed at least 1,455 people, by revised official figures. [34] Nepal's government ended its 40-day search two days before officials told a parliament committee of the plan on Tuesday. [34] Current law does not let a missing person be declared dead quickly. [34]

Why it matters. Without a registered death, families cannot get relief money, compensation or other legal benefits. [34] The changes still have to pass through parliament. [34]

Senegal has put off the start of the school year after floods from Friday to Monday killed at least five people. [35] The rain paralysed parts of Dakar, the capital, and several regions. [35] Schools will now open on 12 October, a delay the country has not made in recent years. [35] Forecasters warn more rain may come in the next few days. [35]

Why it matters. Senegal hosts the Youth Olympics in a few weeks, and Senegal's government must clean and repair schools first. [35] Its rainy season normally ends in October. [35]

Floods since September have caused about 6 billion baht, or $178 million, of damage to Thai industry, the Federation of Thai Industries said on Wednesday. [36] A week earlier its first estimate for Bangkok and 14 provinces was about 1 billion baht. [36] Car assembly plants have enough parts to keep running until 12 October, it said. [36]

Why it matters. The estimate grew six times over in a week. [36] Car plants have parts in stock only until 12 October. [36]

Farmers in southern Madagascar are bracing for El Nino, which experts expect to be the strongest on record. [37] The World Meteorological Organization, the UN's weather agency, warns of a higher risk of drought. [37] Farmer Bien Aimee Mampisaina says the rains no longer come when it is time to plant, so crops and seeds are getting worse. [37] Some farmers now ask for boreholes and pumps. [37]

Why it matters. Southern Madagascar's farms depend on rain arriving on time. [37] El Nino's season there begins in October. [37]

High tides flooded streets in Marin County, north of San Francisco, last week with no storm at all. [13] A mass of warm water is moving up the coast and could raise sea levels by up to a foot. [13] That comes on top of 8 to 12 inches of sea level rise in the last century, a state climate expert said. [13] The state water agency has stockpiled flood supplies at 68 places and is checking 1,600 miles of levees. [38]

Why it matters. Governor Gavin Newsom declared a state of emergency on 21 September. [13] Land burned this summer at Big Sur faces a higher risk of mudslides when the rain comes. [13]

Britain's cereal harvest this year was the lowest on record, with wheat down about 3 million tonnes, or 11%, the farm levy board AHDB says. [39] In the South West, farmers say wheat was down at least 30%, and half on some farms. [39] One Wiltshire dairy farm spent about £100,000 on winter feed, because the grass failed in the heat. [39]

Why it matters. The harvest failed at a time of high costs for farmers, the AHDB says. [39] Milk output fell only 4.5%, because cows must be fed and milked whatever the weather. [39]

Lundy, an island in the Bristol Channel known for its puffins, may have to close because it is running out of water. [40] It has had barely 20% of its usual rain since April, and its reservoir fell to 13%. [40] The 28 people who live there get water shipped from the mainland, and are now pumping water from ponds that wildlife use. [40]

Why it matters. The ferry that ships the water stops later this month. [40] Without the pond water, its managing director says, Lundy would face closing. [40]

Tybee Island, Georgia's most popular beach, should gain sand that drifts down from islands to the north. [41] Jetties, sea walls and a shipping channel to the port of Savannah cut that drift. [41] So since the 1970s the US Army Corps of Engineers has pumped sand back onto it, about every seven years. [41] More than half of the 1.3 million cubic yards it placed in 2019 and 2020 is already gone. [41]

Why it matters. This winter the Corps will try dropping sand dug from the channel in the shallows, so it moves more like natural sand. [41] City manager Bret Bell says the beach is the island's only protection from storm surge. [41]

Yorkshire Water said a £1.5 million scheme to cut sewage spills into the River Ure in Ripon has not worked as promised. [42] It said in 2024 the work would cut spills by about 75%. [42] Spills from one overflow fell from 75 in 2021 to 43 in 2025, about 43%. [42] The company says 2025 was a dry year, which also lowered spills. [42]

Why it matters. These sewers carry rain and waste in the same pipes, so heavy rain pushes sewage into rivers. [42] Local Greens have asked for the company's data on the scheme. [42]

Valar Atomics, a nuclear start-up, plans 456 small reactors in Carbon County, Utah, partly to power data centres. [43] Small reactors like these are still largely untested in the US. [43] The county's coal mines dug nearly 10 million tons in 2006, and none at all since 2023. [43] Utah will lease Valar a square mile of state land for up to 100 years, and the rent goes to schools. [43]

Why it matters. All three county commissioners back it. [43] One candidate for the county commission says most people she met oppose data centres and nuclear plants. [43]

Ghazala Hashmi, Virginia's lieutenant governor, said the planned purchase of Dominion Energy, which supplies power in Virginia, by NextEra Energy is not in Virginians' interest. [44] NextEra announced the all-share deal in May. [44] The deal would make the world's largest regulated power company, with 10 million customers in four states. [44] Virginia's utility regulator held its first local hearing on Wednesday. [44]

Why it matters. In Loudoun County, home to many data centres, most speakers on her tour opposed the deal or wanted it checked harder. [44] NextEra says it would help Virginia build more power at home. [44]

California's governor signed a law making utilities file timetables for big power line projects, and creating a monitor at the state regulator to check them. [45] Nearly 22 gigawatts of solar, wind and batteries depend on lines that are already late, the regulator found last year. [45] The state must add 7 to 8 gigawatts a year for 20 years to meet its climate goals, about twice its current pace. [45]

Why it matters. Without the lines, new clean power plants cannot connect to the grid. [45] The grid operator has approved almost $28 billion of new lines in five years. [45]

Connecticut chose 63.4 megawatts of new solar farms in New Hampshire and Maine last month. [46] But Eversource, its biggest power company, has still not signed contracts for 54 megawatts chosen in December 2025. [46] Eversource told regulators the prices were above market and the state's energy plans were unclear. [46] Connecticut aims for 100% clean power by 2040. [46]

Why it matters. The developers must agree contracts with the utilities before the farms go ahead. [46] Since 2022 only 71 megawatts of solar chosen this way have come online. [46]

Renew Home, which controls more than 8 million home thermostats, has renamed itself Everyday Electric. [47] It is adding electric cars, home batteries and solar panels to its virtual power plant. [47] Its boss says running these devices together can reduce the need for new power stations. [47] It also bought Smartcar, a firm that connects to electric cars. [47]

Why it matters. About 46% of new US home solar systems now come with a battery. [47] The US Department of Energy has estimated such systems could meet 20% of peak demand by 2030. [47]

Australians registered 311.8 megawatts of small solar systems in September, 7% more than in August, SunWiz, a research firm, says. [48] More has gone on roofs so far in 2026 than in all of 2025. [48] A federal rebate for home batteries is driving it, because a battery must sit beside solar panels to qualify. [48] Queensland added the most, 91.8 megawatts. [48]

Why it matters. Systems of 10 to 15 kilowatts are the most common, at 105.94 megawatts in September. [48] Installs from January to September are 43% ahead of last year. [48]

TagEnergy, a Portuguese company, opened France's largest battery at Cernay-les-Reims, in the north-east, on 1 October. [49] It can deliver 240 megawatts for two hours, from 140 Tesla battery units on about three hectares. [49] In its first four months of tests it fed 70.5 gigawatt-hours back to the grid. [49] It helps keep the grid's frequency steady. [49]

Why it matters. TagEnergy's boss says big batteries are now an industrial reality in France. [49] It completed 145 full charges in its first 125 days. [49]

Solar power and batteries supported 982,000 full-time jobs in the EU in 2025, says SolarPower Europe, the industry group. [50] Solar had 874,000 of them and batteries 108,000. [50] Installing panels accounts for 85% of solar jobs, while making them is just 4%. [50] Germany has the most, about 165,000. [50]

Why it matters. For the first time, big solar farms employ slightly more people than rooftop solar, 50.2% of the jobs. [50] The EU added 69 gigawatts of solar in 2025. [50]

Toyo, a Japanese solar maker, opened an expansion of its factory in Humble, Texas, on Tuesday. [51] The plant can now assemble 2 gigawatts of solar panels a year. [51] Toyo plans to spend $357 million more to make solar cells there by early 2028, with 400 workers. [51] It makes cells in Ethiopia and Vietnam today. [51]

Why it matters. A US commerce official at the opening called it the direct result of the Trump administration's policies to bring factories back. [51] Toyo has promised to use only US-made polysilicon, the raw material for cells. [51]

AuroraCell, a Bulgarian company, has launched a 9.7 kilowatt-hour home battery that uses sodium instead of lithium. [52] It says the cells last 20,000 full charges. [52] Hithium, a Chinese battery maker, says sodium is common and spread widely, unlike lithium. [53] Sodium batteries usually hold less energy for their size, so AuroraCell aims this one at homes, where the battery stays in one place. [52]

Why it matters. Lithium prices swing and its supply is concentrated in a few places, so a second chemistry would spread the risk. [53]