Several publications report that US president Donald Trump has issued a permit for a “controversial” oil pipeline. The move comes in spite of a federal judge blocking the “Keystone XL” project in November, the Independent reports. The permit gives TransCanada, the Calgary-based firm behind the project, permission to “construct, connect, operate and maintain” the pipeline in US territory, according to the Washington Post. Speaking to the newspaper about the planned pipeline, Anthony Swift, director of the Natural Resources Defense Council’s Canada project, says: “If built, it would threaten our land, our drinking water and our communities from Montana and Nebraska to the Gulf Coast. And it would drive dangerous climate change.” The decision marks the “latest effort to jump-start one of the most controversial infrastructure proposals in recent US history,” the article adds. The Hill also has the story.

Elsewhere, the Guardian and others report that an Alaska judge has blocked Trump from reversing an Obama-era ban on offshore drilling in the Arctic and Atlantic. Trump gave an executive order to reverse the ban – a key part of “Obama’s environmental legacy” – in 2017. US district court judge Sharon Gleason threw out the reversal, saying: “The wording of President Obama’s 2015 and 2016 withdrawals indicates that he intended them to extend indefinitely, and therefore be revocable only by an act of Congress.” The ruling marks the “third legal blow against the Trump administration’s energy policies” in a week, according to the Washington Post. The Hill also has the news.

Democratic congresswoman Alexandria Ocasio-Cortez appeared in a MSNBC televised town hall on Friday and forcefully defended the “green new deal”, calling climate change “our greatest existential threat”. According to CNBC, she said: “We don’t have time for five years of a half-baked, watered-down position. This is urgent, and to think we have time is such a privileged and removed-from-reality attitude.” The Guardian also covers the town hall, leading with Ocasio-Cortez’s comment that critics of the green new deal are “making fools of themselves”. The Hill and GQ also cover the town hall. In an interview with Huffington Post, former British prime minister Tony Blair appeared “very sceptical” about the green new deal plan. Speaking about Ocasio-Cortez, he says: “She’s an extremely interesting and articulate and dynamic person, that’s for sure. The problem is there are two types of politics in the end. There’s the politics that is the politics of protest and there’s the politics of government. And sometimes the one can lead to other, but they have a different spirit to them. The Green New Deal is raising the issue that needs to be raised. But if you actually look at the detail of it, I think they’re [the Democrats] going to find they’ll really struggle if you’re a Presidential candidate and you’re signed up to it.”

The Guardian has in-depth coverage of the Australian Labor party’s new climate policy, which it plans to enact if it wins the upcoming federal election. The newspaper carries an explainer of how the climate policy would impact sectors, such as transport, heavy industry and energy. Separately, it reports that 50% of new cars would be electric vehicles by 2030 under the Labor climate change policy. The Sydney Morning Herald says the policy shows that Labor leader Bill Shorten is “treading gently” with a “careful climate plan”. The article reads: “Bill Shorten is well aware of the dangers around Labor’s latest climate change approach. Hence the absence of a carbon tax, the use of safeguard mechanisms which were introduced by Turnbull, the exclusion of agriculture except for where farmers and landholders may be able to turn a buck, handouts to trade-exposed businesses and credits to firms that over-achieve.”

Elsewhere in Australian climate and energy news, Reuters reports that the country’s QBE Insurance Group plans to stop offering new policies for thermal coal mines and coal-fired power stations to “help encourage a low carbon economy and combat climate change”. It is Australia’s third-largest insurer. The Guardian reports that Japan is to oppose new or expanded coal-fired power plants, which could be a blow to Australian exports.

Several publications report that landmarks across the world switched off their lights on Saturday to “highlight climate change” during Earth Hour. The Daily Telegraph, Guardian, Reuters and the Hill have coverage.

An editorial in the Washington Post writes that global growth is “supercharging emissions”. The article reads: “Breaking the link between economic growth and greenhouse emissions will require more effort than world governments are applying…Now would be the time for a global leader to pressure these governments to take the long view. There is not much time left to change this picture.”

The South China Morning Post carries an editorial on why “we should all reflect on climate change”. “Predictions that winter could soon be a thing of the past may seem surreal, but what is certain is that the weather is not what it used to be,” the editorial reads. “Officials should review urban planning and embrace more ambitious emission targets in future. Only through concerted efforts can we tackle global warming.”

The Irish Times carries an editorial following the release of a report from the all-party Committee on Climate Action, produced after seven months of “intense scrutiny of how climate breakdown threatens Ireland”. “Few of the measures are radical or new,” the editorial reads. “Most are overdue and, in some cases, such as the redirection of Irish agriculture, they are immensely challenging. But they suggest Irish politicians are beginning to face up to their responsibilities to deliver the kind of extensive and co-ordinated actions so many people desire.” The Irish Sun covers the plans, with a particular focus on proposed carbon taxes. In the Irish Mirror, Lord Henry Mountcharles writes that Ireland “needs to tear up the rulebook as the clock is ticking on climate change”.

The Norwegian Sea has become warmer and fresher between 2011 and 2018, a new study finds. Using monthly estimates of ocean heat and freshwater contents using data from Argo floats, the researchers analysed the Norwegian Sea – comprising the Norwegian and Lofoten basins. The warming and freshening is “mainly explained by two different processes”, the authors say: “Reduced ocean heat loss to the atmosphere and advection of fresher Atlantic water into the Norwegian Sea.”

A new paper aims to answer the challenge of “where biochar should be applied for the maximum agronomic and economic benefits”. The researchers develop “an extensive informatics workflow for processing and analysing crop yield response data as well as a large spatial-scale modelling platform”. Their findings “show an average increase in crop yields ranging from 4.7% to 6.4% depending on the biochar feedstock and application rate”. The study also finds that “biochar application to crop area with an expected yield increase of at least 5.3%–5.9% would result in carbon sequestration offsetting 0.57%–0.67% of US greenhouse gas emissions”.

Tornado warning systems in the US are “inadequate” in terms of preparing mobile home residents to respond safely, a new paper says. Mobile home residents experience higher fatality rates from tornadoes than fixed home residents, the paper notes. The researchers conducted four surveys with residents of the Southeast US – a region with “the highest concentration of tornado fatalities and killer tornadoes”. The paper offers recommendations for how to improve tornado communication.