Over the past 12 months, courts from Indonesia to Australia have made groundbreaking rulings that blocked polluting power plants and denounced the human rights violations of the climate crisis. But 2023 could be even more important, with hearings and judgments across the world poised to throw light on the worst perpetrators, give victims a voice and force recalcitrant governments and companies into action. Although the bulk of climate lawsuits have been filed in the US, most have been thrown out of court or bogged down in procedural arguments. This year will, however, finally see a case go to trial when a group of children and young people between the ages of five and 21 square off against the state of Montana. Over two weeks in June, they will argue that the US state is failing to protect their constitutional rights, including the right to a healthy and clean environment, by supporting an energy system driven by fossil fuels. They will also say climate breakdown is degrading vital resources such as rivers, lakes, fish and wildlife which are held in trust for the public. “Never before has a climate change trial of this magnitude happened,” says Andrea Rodgers, senior litigation attorney with Our Children’s Trust, which is behind the case. “The court will be deciding the constitutionality of an energy policy that promotes fossil fuels, as well as a state law that allows agencies to ignore the impacts of climate change in their decision-making.” She said the trial would be watched around the world and “is set to influence the trajectory of climate change litigation going forward”. Other cases against US states could also be given permission to go to trial. In Canada, a ruling is expected this year in the country’s first climate lawsuit to have had its day in court. Seven young people, fronted by now-15-year-old Sophia Mathur, made history last autumn when they challenged the Ontario government’s rollback of its 2030 greenhouse gas emissions reduction target. And in Mexico, young people have led several important court cases challenging the slow pace of the country’s clean energy system. The supreme court is due to decide whether they are allowed to seek justice in at least one case. In South Africa – already a hotspot for climate litigation – there could be decisions in several important cases. One, a constitutional challenge to the country’s plan to build new coal-fired power stations during the climate crisis, was heard in November and a ruling is expected soon. Meanwhile, the Australian crucible of successful climate litigation will hear a class action case in June led by Torres Strait islanders Pabai Pabai and Guy Paul Kabai, who argue the state should slash its emissions to save their islands from rising sea levels and other devastating climate impacts. In New Zealand, the court of appeal is expected to hear Northland iwi leader Mike Smith’s appeal against the high court striking down his claim against the New Zealand government, in which he sought a declaration that it had breached its climate obligations. On the other side of the world, the European court of human rights has several climate cases on its books, all of which argue that government inaction in limiting dangerous global heating risks basic human rights such as health and life. At its first public climate hearing in March this year, a group of older Swiss women known as the KlimaSeniorinnen Schweiz will say they are particularly vulnerable to the climate crisis because their health is at risk from heatwaves. They will get to make their arguments in front of the court’s grand chamber, which is reserved for the most serious cases, and will be supported by two prominent British lawyers, Jessica Simor and Marc Willers. Although this is a European case, it will cause international ripples. Kelly Matheson, deputy director of global climate litigation at Our Children’s Trust, which is advising on climate science in three cases before the court, said the decision by the court’s 17 judges would have a “profound effect on courts throughout the world as their finding will inform and influence the decision made in other judicial processes”. At national level, campaigners will be asking judges to make climate orders against the governments of Italy, Belgium and France, following a string of successful similar European cases. Sarah Mead, co-director of the Climate Litigation Network, says these cases are crucial because a positive outcome can enhance government accountability, particularly in OECD countries with significant historical responsibilities and more capacity to cut their emissions. They also help “narrow the global emissions gap and further foster citizens’ mobilisation on the need for stronger climate action”. There will be movement on an international level too. Early this year, the UN will vote on a key resolution about human rights and climate change. If passed, the international court of justice will have to advise on what obligations states have under international law to protect the rights of present and future generations against the negative impacts of climate change. This work has been led by the vulnerable island state Vanuatu, and has support from governments all around the world. Private sector It is not only governments in the firing line; climate litigation against the private sector will continue to grow. In the US, there might finally be an answer to the question of which courts will handle the plethora of lawsuits against the fossil fuel industry. Companies have been pushing to have these cases heard at the federal level, where they believe they stand more chance of success, but judges have consistently ruled against them. The supreme court has been asked to intervene, and if it takes up the case next year it may finally draw a line under the issue. Richard Wiles, president of the Center for Climate Integrity, says that if the supreme court agrees with federal judges it would remove one of the last procedural hurdles and mean cases can start to move on to talk about the actual issues at stake – were the actions of fossil fuel companies reasonable and what responsibility do they bear? Following pre-Christmas wins against billionaire Clive Palmer’s attempt to build a huge thermal coalmine and Santos’s $4.7bn Barossa offshore gas project, Australian climate campaigners are on tenterhooks awaiting a decision on their challenge to Woodside’s $16bn Scarborough gas project because of the impact of its greenhouse gas emissions on the Great Barrier Reef. Meanwhile, Brazil’s courts will hear a case against Brazil’s national development bank (BNDES) and its investment arm BNDESPar. The Brazilian NGO Conectas Direitos Humanos wants them to develop a greenhouse gas emissions reduction plan to guide their investments. It is the first case of its kind against a development bank anywhere in the world, and could have significant repercussions on wider climate finance. In Germany, there could be a ruling in a landmark lawsuit brought by the Peruvian farmer Saúl Luciano Lliuya against the energy company RWE for contributing to the climate crisis. The court sent judges to Peru last year to determine the level of damage, and its decision will be watched very closely by the private sector. Several lawsuits have been filed to try to block TotalEnergies’ controversial East African Crude Oil Pipeline. One filed under a novel “duty of vigilance” law in France had a hearing in December and there could be a ruling this year. In South Africa, courts will decide whether Shell was legally given exploration rights off the ecologically sensitive Wild Coast, after the company appealed against an order to halt seismic testing. There may also be movement next year in Shell’s appeal against a landmark ruling by a Dutch court, which in 2021 ordered it to cut its carbon emissions by 45% by 2030. Although the court was clear that Shell must begin complying with the ruling straight away, Milieudefensie (the Dutch arm of Friends of the Earth), which brought the case, does not think it is doing enough to meet the target. Shell’s directors will also be under an unprecedented level of scrutiny this year. ClientEarth sent a letter to the company’s board in 2022, warning that it was prepared to start a legal challenge in the UK if Shell does not handle its climate risks better. If ClientEarth follows through, this would be the first derivative action anywhere against a board for failing to consider efforts towards achieving net zero. When it comes to greenwashing – a fast-growing area of climate litigation – expect to hear more on allegations that Dutch airline KLM’s adverts promoting the company’s sustainability initiative are misleading and claims that the gas company Santos breached Australian corporate and consumer law over clean energy and net zero plans. Whatever happens in those cases, expect to see many more lawsuits filed this year, as well as more creative uses of the law. These will be filed against governments of all levels, based on the most cutting-edge science, as well as against companies. The financial sector, in particular, is likely to be a big target, and there will be continuing waves of related litigation targeting plastics and biodiversity loss. This year is “shaping up to be a really important year for climate litigation”, says Mead. A version of this article was originally published on The Wave, a newsletter on climate litigation