The United Nations weather agency said carbon dioxide levels in the atmosphere reached record highs last year, intensifying climate change and extreme weather. The World Meteorological Organization said CO2 growth rates have tripled since the 1960s, reaching levels that existed 800,000 years ago. The report, released Wednesday, highlights emissions from coal, oil, and gas, along with wildfires, as major contributors. Despite flat fossil fuel emissions last year, CO2 levels continue to rise. The agency has urged policymakers to reduce emissions, warning that the world is heading into a dangerous state. Other greenhouse gases like methane and nitrous oxide have also hit record levels.

California Gov. Gavin Newsom has signed a bill extending the state's cap-and-trade program through 2045. The program sets a declining limit on total planet-warming emissions in the state from major polluters. The new law potentially boosts carbon-removal projects and requires the program to align with California's target of achieving so-called carbon neutrality by 2045. Newsom also signed laws to speed up permitting for oil production in Kern County, refill a fund that covers the cost of wildfire damage when utility equipment sparks a blaze and allow the state's grid operator to partner with a regional group to manage power markets in western states.

Scientists are criticizing two key documents from the Trump administration that challenge the idea that climate change endangers the public. The documents from the Environmental Protection Agency and Department of Energy argue that climate change's impact is unclear and that U.S. cuts to greenhouse gas emissions have little global effect. Most of the scientists who responded to questions from The Associated Press said the reports misuse or misinterpret their work. A common critique was that the documents cherry-pick information to downplay climate change's severity. When asked to grade the documents, those surveyed most frequently gave the work an F.

A startup called Gigablue claims to have reached a milestone by selling 200,000 carbon credits for its ocean-based carbon capture technology. The company says its patented particles grow algae that trap carbon dioxide, which then sinks to the ocean floor. Outside scientists, however, question the effectiveness and environmental impact of this method, citing a lack of public data and concerns about marine ecosystems. Gigablue has conducted trials in New Zealand and plans to expand operations. While some buyers trust the company's promises, experts remain skeptical about its unproven technology and the broader implications of such ocean-based carbon removal efforts.