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  2. US mid-termsHeating up
  3. AICooling
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Colder seas may explain a quarter of ice-age CO2 drop

Published

Grey ocean under an overcast sky with pale icebergs drifting near a rocky shore.

A paper in Nature Communications proposes that plankton respiration slows more than photosynthesis in colder water. The authors estimate this effect explains about a quarter of the fall in carbon dioxide during the last ice age.

The authors argue that when respiration slows more than photosynthesis, more carbon sinks to the deep ocean. This offers a physical explanation for part of a long-debated question in climate science. The paper is peer-reviewed. The quarter figure comes from the authors' modelling, and other researchers have not independently checked it. It is also an estimate of past climate, not a measurement.

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Elections Hot

What you need to know

Voting in the 2026 Local Government Elections is under way at 23,696 stations, and the Electoral Commission of South Africa (IEC) reported a smooth start on 4 November. Stations opened at 7am and close at 9pm, and by 10am preliminary figures showed 3,523,691 voters had cast ballots.

There were problems: unused ballot papers were stolen from Mnyameni Secondary School near Durban, police opened a case, and the IEC relieved the station staff of duty. Some voters in Tshwane said they were turned away for wearing party shirts, but the IEC denied this and said only mayoral candidates' entourages were barred.

ANC chairperson Gwede Mantashe told members not to query the results or discredit the IEC, while the IEC said false online claims show routine procedures as fraud.

  1. IEC dismisses MK Party worry about dead people on voters' roll
  2. IEC says local election voting went largely smoothly
  3. IEC says about 12 million had voted by 5pm

See every update

US mid-terms Heating up

What you need to know

Democrats won back both the US House and Senate in the midterm elections held on 3 November, according to media projections. Exit polls showed voters were angry about high prices and the direction of the country, and rebuked President Donald Trump.

Before the vote, US forces struck targets on Qeshm Island in Iran, while Republicans struggled to defend the war against Iran on the campaign trail. Iranian officials said US voters rejected the war, and Tehran stayed on high alert for possible new US strikes.

Markets reacted, with the dollar hitting a one-month low and the rand firming to around R16.55, as analysts pointed to fears of gridlock in Washington.

  1. Iran welcomes Democratic wins in US midterm elections
  2. Democrats win US Congress in midterm vote, projections show
  3. Ramaphosa wants US trade deal after AGOA suspension

See every update

AI Cooling

What you need to know

Nvidia has told its cloud computing clients to sell at least 51% of their services to non-Chinese companies, according to five people with knowledge of the matter. Anthropic said it has committed to spend close to $900bn on AI infrastructure, and that its computing costs are rising faster than its revenues.

Elsewhere, reports from unnamed sources say OpenAI's latest funding round is falling short of expectations, and a judge let the NAACP pollution case against xAI proceed. In South Africa, the VAST AI investment scheme went offline on 30 October after withdrawals marked approved did not arrive, according to a news investigation.

  1. Accenture faces accusations over AI report with false citations
  2. CrowdStrike to buy two AI security startups
  3. Google lets schools turn off AI tools but limits Search

See every update