Climate, in brief

Arctic sea ice, the frozen seawater that floats on the ocean around the North Pole, shrank to its smallest area of the year on 12 September. [1]

NASA and the US National Snow and Ice Data Center (NSIDC), which measure the ice by satellite, said it covered about 4.6 million square kilometres. [1]

That ties 2008, 2010 and 2025 as the 10th-lowest summer low since steady satellite records began in late 1978. [1]

The ice grows through the dark, cold winter and melts back each summer, usually reaching its lowest point in September. [1]

This year it reached its winter peak on 15 March and then melted until 12 September. [2]

The 20 lowest summer lows ever measured all came in the 20 years from 2007 to 2026. [1]

The September low has been fairly steady in recent years. NASA scientist Linette Boisvert says more cloud over the last decade has kept sunshine from speeding up the melt. [1]

"We've plateaued, but we're still low," said Walt Meier of the NSIDC, comparing today with the early years of the record. [1]

At the other end of the planet, Antarctic sea ice lost about 300,000 square kilometres in six days in August, then started growing again. [1]

Meier said winds pushed and packed the thin outer ice together, and called the size of the drop unusual. The scientists will not yet call Antarctica's lower recent peaks a trend. [1]

Shipping is already moving into the Arctic. On 15 August a Chinese container ship set off for Europe on a new regular route around Russia's northern coast. [3][4]

Its operator, Sea Legend, calls the route the Ice Silk Road. Another Chinese firm plans to move more than 1 million tonnes of cargo that way next summer. [3]

Why it matters. Watch the Antarctic winter peak, due in late September or early October: another low peak would add to a run that NASA and NSIDC scientists are still not ready to call a trend. [1]

Hurricane Polo grew into a Category 5 storm, the strongest kind, in the Pacific off Mexico this week. [5] Mexico's president, Claudia Sheinbaum, said it was not expected to hit the coast directly, but warned Jalisco, Colima and Michoacan to stay alert. [5] Up to 15cm of rain and dangerous surf are forecast. [5] The US weather agency NOAA said very warm ocean water was feeding the storm. [5] On 19 September a key patch of the Pacific was 3.05C above average, beating the 3.02C record from 2015. [5]

Why it matters. El Nino is a natural warming of the Pacific that comes every two to seven years and heats the planet for about a year. [5] This one now holds the daily record, and its peak is not expected until later this year. [5]

Zeke Hausfather, a climate scientist at the research group Berkeley Earth, wrote in the journal Nature that forecasts give this El Nino a more than 90% chance of beating every one since the 1870s. [6] In early September the central Pacific was about 2.9C above its 30-year average. [6] In the four strongest El Ninos between 1980 and 2016, southern Africa had about an 80% chance of a dry rainy season. [6] Planting there begins in October. [6]

Why it matters. South Africa's maize harvest fell by nearly half in the 2015-16 El Nino. [6] Rain is already falling off in Indonesia, where El Nino fires and haze in 2015 were linked to about 100,000 early deaths across Indonesia, Malaysia and Singapore. [6]

Bolivia's Congress approved a $1.9 billion, three-year loan from the International Monetary Fund, the lender countries turn to when they run short of dollars. [7][8] Hours later President Rodrigo Paz ended subsidies on diesel, the fuel for trucks, buses and tractors, which now sells at world prices. [7] Falling gas exports had left Bolivia short of dollars to import fuel, and shortages began in 2023. [7] When Paz's government took over, only $52 million of its $3.17 billion in reserves was cash it could spend. [8]

Why it matters. The main labour federation says the cuts will raise living costs, and road blockades paralysed the country in June and July. [7] Bolivia's government is paying about $79 million in cash help to 2.9 million Bolivians, and the IMF's board still has to approve the loan. [7]

Brent crude, the world's main oil price, traded below $100 a barrel on Wednesday as traders hoped talks at the UN could calm the wars in the Middle East and Ukraine. [9] Diesel stayed dear. The US average was $6.52 a gallon, half a cent below Tuesday's record, according to the motoring group AAA. [9] Some Republicans in close races want US diesel exports banned, and President Trump said he was open to it. [9]

Why it matters. Supporters say a ban would bring relief to farmers and truckers. [9] The oil industry and some analysts warn it could backfire and make the global energy crisis worse. [9]

The US Federal Energy Regulatory Commission (FERC), which oversees power lines between states, on Tuesday rejected power company ComEd's attempt to cancel a grid agreement with a data centre planned in Joliet, Illinois. [10] PowerHouse Hillwood's project would draw 1.8 gigawatts and cost $20 billion. [10] The developer says it met the deal's credit rule by posting $1. [10] FERC left that dispute to a federal court. [10]

Why it matters. Commissioner David Rosner said deposits keep a project's risk with the developer, not the public, and Commissioner David LaCerte called the $1 an embarrassing legal fiction. [10] Grid operators must answer FERC's June orders on connecting very large users by mid-November. [10]

New Jersey fined DataOne $1.07 million on Tuesday for running 62 gas-powered generators at its data centre in Vineland without the required permits. [11] State officials said it is the largest fine New Jersey has issued to a data centre operator. [11] The campus, due to be finished this year, needs 350 megawatts, enough to power a medium-sized city. [11] Neighbours have filed a federal lawsuit over noise from the site. [11]

Why it matters. Data centres are racing to find power faster than utilities can build grid connections, so some install their own generators. [11] Governor Mikie Sherrill said the build-out has to benefit communities in New Jersey. [11]

A 14 September memo from Brian Nesvik, director of the US Fish and Wildlife Service, says killing an endangered animal breaks the law only when the animal was deliberately targeted. [12][13] For decades the agency held people liable even for accidental harm to species such as grizzly bears, manatees and spotted owls. [12] Experts say timber companies could now log forests even knowing it would kill protected birds. [12]

Why it matters. Dan Ashe, who ran the agency under President Obama, called it a huge loophole. [12] Twenty states and Washington DC sued on 9 September over earlier changes to what the law counts as harm. [13]

Brazilians elect a president on 4 October. [14] Former president Jair Bolsonaro is under house arrest and cannot run, but his son Flavio, a 45-year-old senator, is on the ballot. [14] During Jair Bolsonaro's presidency, from 2019 to 2023, clearing of the Amazon rainforest soared and reached a 15-year high in 2021. [14] Claudio Angelo of Brazil's Climate Observatory expects Flavio to govern the same way, or worse. [14]

Why it matters. Flavio Bolsonaro's candidacy has raised fears for the future of the rainforest. [14] Angelo called the vote a do-or-die moment for the Amazon. [14]

Gerard Barron, head of the Metals Company, argued at a New York Times event on Wednesday for mining metal-coated rocks from the Pacific seabed. [15] The fist-sized rocks hold nickel and cobalt, which go into batteries and electronics. [15] His company applied for US permits after President Trump called for them in international waters. [15] The US has not ratified the UN treaty on the law of the sea. [15]

Why it matters. The International Seabed Authority, 171 countries plus the EU, has debated mining rules for over a decade and says they should be ready by the end of the year. [15] Scientists still know little about what mining would do to life on the deep sea floor. [15]

Buyers paid about $75 billion for Chinese batteries and grid equipment in the first seven months of 2026, around $20 billion more than a year before, according to data from the energy research group Ember. [16] Imports of Chinese solar systems averaged about $2.7 billion a month this year, less than half their March 2023 peak. [16] A Reuters commentary argues the panels were a victim of their own success. [16]

Why it matters. Forty countries have each spent more than $1 billion on Chinese solar systems since 2018. [16] Their power companies now need batteries and grid equipment to store and move all that midday power. [16]

Texas, the biggest oil producer in the US, overtook California earlier this year as the country's largest generator of power from solar farms, the BBC reports. [17] On hot afternoons solar now supplies about a third of the state's electricity, says Mark Stover of the Texas Solar and Storage Association. [17] The developer OCI sells power at $40 a megawatt hour, fixed for 25 years, while new US coal plants cost nearly $90. [17]

Why it matters. Farmers lease their land for 25 to 30 years, and one, Cargil, earns $200,000 a year from 600 acres, which kept his farm going through drought. [17] In Franklin County some residents fought new farms over cleared oak trees and fears of battery fires. [17]

New Zealand has approved nearly 9,000 square kilometres of forest that earns carbon credits, which polluters buy to make up for their emissions. [18] Because credits pay long before the trees are cut, forestry investors can outbid sheep and beef farmers for land. [18] About 3,300 square kilometres of those farms were sold for trees since 2017, and grazing land prices rose 9.7%. [18] In the farming area around Pongaroa the rugby club folded in 2022. [18]

Why it matters. New Zealand's government climate advisers expect these forests to deliver a quarter of the cuts needed for New Zealand's 2026-2030 target. [18] Critics say that lets polluters buy credits instead of cleaning up, and in the latest yearly figures farm sales for forestry slowed to about 160 square kilometres. [18]

A study in the journal Nature Climate Change looked at heatwaves on land from 1979 to 2023. [19] It found the first heatwave of the year now arrives about 3.3 days earlier each decade, and the last ends about 5.4 days later. [19] The heatwave season grew by about 8.7 days a decade, and got longer across 92% of the world's land. [19] Dry regions shifted more than humid ones. [19]

Why it matters. The authors say early warning systems and plans for heat need to account for when heat arrives, not only how hot it gets. [19] The study also found heatwaves have recently tended to arrive more suddenly. [19]

Researchers tested 4,000 people in four studies on how well they could tell strong climate arguments from weak ones, and published the results in Nature Climate Change. [20] What people already believed shaped their judgement most. [20] Placing an argument in a hostile party-political setting did not make people more biased. [20] A short warning that an argument might contain a common logical mistake helped people separate weak ones from strong ones. [20]

Why it matters. It points to a cheap way to help people judge climate claims, and it worked across beliefs and political parties. [20]

The Texas Rangers, the state's top police investigators, are running a homicide investigation into the owners of Camp Mystic, court papers released this week show. [21] Twenty-eight people died at the camp in catastrophic flooding last year. [21] Search warrants carried out last week sought the owners' messages as possible evidence of manslaughter, negligent homicide or child abandonment. [21]

Why it matters. The warrants list crimes the Rangers are looking into, not charges anyone faces. [21]

Forecasters expect a powerful, slow-moving nor'easter, a storm whose strongest winds blow in from the north-east, to strengthen off North Carolina on Friday. [22][23] A storm like this is rare in September, and this one is tracking close to the coast. [22] It could then spread from the Mid-Atlantic to New England. [23] It will arrive with higher-than-normal tides, raising the risk of coastal flooding and beach erosion. [22]

Why it matters. Millions of people could be affected, and how much damage it does depends on how close to the coast it runs. [23]

The World Bank's president, Ajay Banga, is drawing in private investors, from pension funds to the fund manager BlackRock, to pay for projects in poor countries, the New York Times reported last week. [24] The push was first meant to raise the trillions needed to tackle climate change. [24] With President Trump leading the US, the bank's largest shareholder, Banga has shifted its aim toward roads, infrastructure and jobs. [24]

Why it matters. Private investment through the bank has nearly tripled in three years. [24] Banga says public and charity money alone will never cover what poor countries need for energy, schools and health. [24]

South Korea's government was due to brief lawmakers this week on a $350 billion package of investments in the US, part of a trade deal that cut US tariffs on its goods to 15%. [25] A gas power plant in Texas is the first possible project. [25] Media reports also mention US nuclear reactors, a stake in the reactor maker Westinghouse and a long-delayed Alaska gas export project. [25]

Why it matters. South Korea's President Lee has said the two sides disagree over whether the projects will make money. [25] An opposition lawmaker warned the country could carry an unfair share of the risk in energy projects. [25]

Delcy Rodriguez, Venezuela's acting president since a US raid captured Nicolas Maduro in January, came to New York for the UN General Assembly. [26][27] Her team began talks with US counterparts on energy, debt and mining, which are expected to end in signed agreements. [26] The Inter-American Development Bank is drawing up a two-year plan for Venezuela focused partly on electricity. [26]

Why it matters. At the UN, Rodriguez said she wants cooperation in the energy sector, after a deal last month gave the US a stake in Venezuela's oil reserves. [27] She said that deal will modernise the country's oil industry. [27]