The hottest year on record was 2023 — until 2024, when the Earth’s average temperature reached 1.55C above the pre-industrial average, according to the World Meteorological Organisation, and when the average ocean temperatures hit a new high.
June 2025 was the third-warmest June in 176 years, after 2024 and 2023, according to a recent report by the US National Oceanic and Atmospheric Administration.
Around the world, many of the most vulnerable citizens, communities and nations are suing countries and corporations over what they see as a lack of climate action.
They want to force polluters and governments to pay for past harms and to avert future threats, and they’re using the law to assign blame for damage.
Opponents say climate policy is not a matter for the courts, but for agreements between nations, such as those on emissions reduction, methane and deforestation.
On July 23, the International Court of Justice said countries that fail to do what they can to limit global warming to the critical threshold of 1.5C may be violating international law.
The advisory opinion was the outcome of a long-running case led by the government of Vanuatu, a Pacific Island nation that’s confronted with rising sea levels and an intensification of tropical cyclones.
The landmark opinion delivered by the United Nations’ highest court that governments must protect the climate is already being cited in courtrooms, as lawyers say it strengthens the legal arguments in suits against countries and companies.
While countries that breach their official pledges will not actually face prosecution, the ICJ ruling sets an authoritative benchmark for assessing where they are falling short, both in terms of emissions cuts and finance to poorer nations.
Rulings in favour of claimants can have a lasting effect on governance.
More than 80% of the 226 new cases filed in 2024 are considered strategic, meaning they are intended to both address a specific issue and influence wider policy and debate, according to a report from the London School of Economics’ Grantham Research Institute on Climate Change and the Environment.
National governments are being targeted over climate action that litigants say is insufficient to meet international green pledges.
Corporations and individuals aren’t immune, too.
In the US, big oil companies and electricity producers have been targeted.
In Europe, local and national authorities have been sued because their clean-air plans fail to meet European Union requirements.
A constitutional court in South Korea found last year that the government’s lack of climate goals between 2030 and 2050 failed to guarantee a gradual and continuous reduction of emissions.
In another major case in 2024, a group of elderly Swiss women won a landmark ruling before the European Court of Human Rights, which sided with their claim that Switzerland hadn’t done enough to shield its residents from the ravages of climate change.
Campaigners have also won major cases against the UK, Colombia and South Africa.
Around 45 of the 226 new climate cases filed in 2024 targeted companies or their directors and senior officers, according to the LSE report.
Almost $200tn of investment is needed by 2050 to reach net-zero emissions, according to a BloombergNEF estimate in 2023.
The ICJ opinion said climate change was an “urgent and existential threat,” citing decades of peer-reviewed research, even as scepticism has mounted in some quarters, led by the US.
A document seen by Reuters shows the US Environmental Protection Agency may question the research behind mainstream climate science and is poised to revoke its scientific determination that greenhouse gas emissions endanger public health.
Protecting the planet is a global endeavour that only works if countries agree to take collective action. Climate change sparked a trail of extreme weather and record heat in 2024, with the UN urging the world to pull back from the “road to ruin”.