California has passed a law committing to entirely carbon-free electricity sources by 2045. Under the terms of the legislation, all utility companies must get 60% of their energy from renewable sources by 2030. By 2045, all Californian electricity must come from carbon-free or renewable energy. At a signing ceremony, Governor Jerry Brown vowed to meet the terms of the Paris Agreement and to “continue down that path to transition our economy to zero carbon emissions”. Brown also signed an executive order calling for the state to slash its overall emissions to zero by 2045 and then go negative, reports the San Francisco Chronicle. “Brown’s signature on the clean-energy bill was widely expected, but the executive order was not. California had previously set a target of cutting the state’s greenhouse gas emissions 80% by 2050 — already considered a difficult task,” the article notes. Brown touted the move as a lodestar for other governments and nations, says Time: “It’s not going to be easy and it will not be immediate, but it must be done,” he said, adding that California is “doing stuff that the rest of the world, most of the world, is just hoping they might get to someday”. Bloomberg, Reuters and the Hill also have the story. Meanwhile, the Financial Times and Bloomberg report that the former chair of the US Federal Reserve, Janet Yellen, has backed a carbon tax as “the cleanest and most efficient way to address” CO2 emissions. And finally, Reuters reports that New York Governor Andrew Cuomo has directed the state’s Department of Environmental Conservation to promote regulations to phase out the use of hydrofluorocarbons (HFCs). The legislation, to be implemented from 2020-2024, is expected to reduce HFC emissions by more than 20% of projected levels by 2030.

European Union lawmakers yesterday backed a more ambitious CO2 reduction target for fleets of cars and vans of 45% by 2030. The draft rules endorsed in the European Parliament’s Environment Committee would also set an interim goal of a 20% reduction by 2025. The 45% target is “much more than the 30% reduction proposed by the European Commission”, says Politico, and “a world away from the 20% sought by the auto industry”. The revised targets still needs to pass a vote in the European Parliament’s plenary session, expected in October. If approved, EU lawmakers are set for tough talks with the bloc’s 28 governments on a final law, as nations with big automotive industries fear stricter rules could cost growth and jobs. In related news, Reuters reports that UK prime minister Theresa May will today announce an extra £106m in funding to boost the research and development of environmentally-friendly vehicles, batteries and low-carbon technology. In a speech at the UK’s first-ever Zero Emission Vehicle Summit, held in Birmingham, May will say that the “measures will drive the design, use, uptake and infrastructure necessary for cleaner, greener vehicles – and in doing so, it will help us drastically reduce a major contributor to our global warming emissions, as we seek to meet the Paris climate change agreement”, reports the Press Association. At the same event, Carolyn Fairbairn, director-general of the Confederation of British Industry, is expected to say the government has a “vital role to play” by “making vehicles affordable and by joining forces with business to invest in charge points across our road networks”, reports Independent. And finally, the Times reports that the company behind Williams Formula One motor racing team is to open the first manufacturing site dedicated to making batteries for electric cars.

If the world doesn’t change course by 2020, “we risk missing the point where we can avoid runaway climate change”, UN Secretary General Antonio Guterres has warned. Speaking at the United Nations headquarters in New York, Guterres said he is alarmed by the paralysis of world leaders on what he called the “defining issue” of our time. Guterres called for global leaders to meet with him at a special summit in New York in September next year, arguing it would give the world the push it needs just before the countries that have signed the Paris agreement will review and increase their commitments to cut carbon. Guterres also warned against allowing the forthcoming climate talks in Katowice in Poland in December from “remind[ing] us of Copenhagen,” referencing the infamous failed meeting in the Danish capital in 2009. The New York Times and Financial Times also have the story. There is also continued coverage of the interim climate talks in Bangkok last week. Politico warns a “deep divide between developed and developing countries is casting a shadow” over the Katowice talks, while InsideClimate News reports of “growing complaints that the US and other wealthy countries are trying to manipulate the rules to protect polluters and weaken their own commitments”.

There is a 70% chance of an El Niño event developing before the end of this year, according to the World Meteorological Organisation (WMO). In its seasonal climate outlook, the WMO says that the intensity of the expected event is still uncertain, but it is unlikely to be as strong as in 2015-16. The recurrence of the event so close to the previous one suggests that climate change may be having an impact of the El Niño cycle, says WMO Secretary-General Petteri Taalas: “2018 started out with a weak La Niña event, but its cooling effect was not enough to reduce the overall warming trend which means that this year is on track to be one of the warmest on record.”

The Trump administration “is preparing to make it significantly easier for energy companies to release methane into the atmosphere”, according to documents leaked to the New York Times.The Environmental Protection Agency – as soon as this week – plans to make public a proposal to weaken an Obama-era requirement that oil and gas companies monitor and repair methane leaks. In a related move, the Interior Department is also expected in coming days to release its final version of a draft rule, proposed in February, that essentially repeals a restriction on the intentional venting and “flaring” of methane from drilling operations. The Hill also covers the story.

The French state-controlled power company EDF, which is building the Hinkley nuclear power project in the UK, needs to show a new generation nuclear reactors work well before any other plants are built, says France’s new environment minister Francois de Rugy. In an interview with French newspaper Le Monde, de Rugy said his gut feeling was that nuclear power was not an energy source for the future, but added that there should be no “war of religions” on the issue. De Rugy said “EDF should demonstrate that the EPR [European Pressurised Reactor] works, which is not the case yet. Nobody is able to guarantee a date for its connection to the grid. It also has to demonstrate that the EPR is competitive in terms of costs”, reports the Financial Times. De Rugy added that “the important thing is to know what the economic data is in the nuclear sector and in the field of renewable energies. And to know what the safety data is. Nuclear risk is not a small risk that can be brushed away”, notes Climate Home News.

Emissions of the greenhouse gas nitrous oxide from rice farming might be much larger than previously thought, a new study suggests. A technique brought in to reduce water use and emissions of methane involves intermittently flooding paddy fields, rather than flooding them year-round. But results from working farms in southern India reveal that while reducing methane levels, this method also produces up to 45 times more nitrous oxide than constantly flooded fields. Overall, this means rice farming could be having twice the warming impact, says Mail Online. Typically, most rice producing countries do not report their nitrous oxide emissions.

Writing in the Guardian, Richard Black – a former BBC science and environment correspondent and now director of the thinktank the Energy and Climate Intelligence Unit – comments on the BBC’s new climate change reporting guidance, leaked to Carbon Brief last week. “The basic briefing document for the course is short, but it’s a good start,” says Black. “Climate science, though, is just part of the picture,” he adds: “The corporation’s coverage of energy could do with an infusion of new thinking on issues linked to climate change…the BBC has yet to catch on that a transformation of the entire global energy system is a big story”. But the “real takeaway” is that “the BBC has decided that it no longer cares about groundless criticism”, concludes Black. “The reality is, though, that climate and energy contrarians are exerting less and less influence on media or politics…If BBC bosses have decided that from now on they are going to free output from the occasional grip of the UK’s climate contrarian elite and stand up for evidence – good on them”.

California governor Jerry Brown’s “commitment to resolving the existential challenge of climate change will position him as a global elder statesman when he leaves office next year,” writes Nathan Gardels, the editor in chief of “The WorldPost”, a partnership of the Berggruen Institute and the Washington Post. Gardels runs through Brown’s achievements, including setting up a worldwide “network of the willing” on global warming in the wake of the US decision to withdraw from the Paris Agreement, meeting Chinese President Xi Jinping one-on-one to discuss how to cooperate on climate change, and hosting this week’s Global Climate Action Summit in San Francisco. “A global role, for which he is wholly suited, now beckons,” says Gardels. “Becoming an elder statesman on climate change is the natural next step for a proven leader with lots left to offer”.

The ability of the world’s peatlands to absorb CO2 from the atmosphere is likely to increase until 2100 and then fall, a new study suggests. Using modelling, the researchers find that the decline of CO2 storage in peatlands is likely to decline at the end of the century even if efforts are made to limit global warming to 2C above pre-industrial levels, which is the aim of the Paris Agreement. “Peatlands will remain a carbon sink in the future, but their response to warming switches from a negative to a positive climate feedback (decreased carbon sink with warming) at the end of the twenty-first century,” the authors say.

A first assessment of tropical dry forests in the miombo region of Zambia finds that the vegetation is currently acting as a carbon sink, despite being significantly threatened by human activities. The researchers found that some plant species were noticeably better at storing carbon than others, including several species of legumes. Threats facing the miombo savannahs currently include road building, fragmentation for agricultural land and fires, the authors say.