Latin America
The annual report from the UK advocacy group found Latin America remains the most dangerous part of the world for environmental and land defenders, accounting for 85 percent of the 196 murders documented last year.
The majority were concentrated in just four countries: Colombia, Brazil, Honduras and Mexico.
Colombia had the worst record in 2023, with a total of 79 killed, according to the report.
The findings on Colombia are a sharp contrast to promises by the government of President Gustavo Petro, who took office in 2022 and who has pledged to end the country's 60-year conflict and pursue environmental justice for communities.
The country is also the host nation for this year's United Nations COP16 biodiversity conference.
Peace negotiations with various armed groups - some of which are linked to the killings of environmentalists - have also stalled.
Colombia was the most dangerous country for environmentalists in 2022, with at least 60 reported killings, according to last year’s Global Witness report.
"[This year's] figure is very embarrassing for us in the country," said Astrid Torres, coordinator for Somos Defensores, a Colombian human rights group.
Torres said the issue was not just the responsibility of the sitting government but also of state institutions, such as prosecutors and local authorities.
'Crackdown on activists'
The report also sounds the alarm on a "crackdown on environmental activists across the UK, Europe and the US", warning "laws are increasingly being weaponised against defenders".
It pointed to legislation in Britain and in the United States allowing harsher penalties for protesters and activists facing "draconian levels of surveillance" in the European Union.
In Britain, it highlighted the case of activist David Nixon, who served four weeks in jail after defying a judge's order barring him from using climate change as a defence.
"We should be allowed to mention the climate crisis wherever we go, especially in front of a jury," he told news agencies.
Global Witness urged "decisive action" from governments to protect defenders.
NGO finds 177 environmental activists murdered worldwide in 2022
Dangers in Asia
In Asia, the Philippines continued to be the most dangerous place for with 17 murders. The report also highlighted a growing number of abductions across the region.
This "has emerged as a critical issue, reflecting broader systemic efforts by power holders to suppress dissent and maintain control over land and resources", it said.
Among those affected were Jonila Castro and Jhed Tamano, two young activists opposed to land reclamation projects in Manila Bay in the Philippines.
They have accused the military of abducting them, though authorities claim the women belonged to a communist insurgency and had sought help after leaving the movement.
"Since our release, the threats have continued," the pair said in the report.
Underestimated figures
In Africa, Global Witness recorded just four deaths, but warned the figure was likely a "gross underestimate" given the challenge of collecting information.
Across the world, Indigenous Peoples, who have accumulated wisdom, knowledge, and practices for millennia, are also targeted.
Global Witness warns that, all over the globe, governments and corporations are increasingly wielding the law to suppress environmental activism.
"Activists and their communities are essential in efforts to prevent and remedy harms caused by climate damaging industries," said the report's lead author Laura Furones.
"We cannot afford to, nor should we tolerate, losing any more lives," she added.