More and more people are finding themselves on the frontline of an intensifying battle to defend their environment from corporate or state exploitation, according to a new report.
And more are paying for it with their lives, the report added.
Independent organisation Global Witness (GW) says it has verified that 908 citizens have been killed in the past 12 years for trying to protect rights to their land and environment.
Over the past four years, the death rate has risen to an average of two activists a week. The worst year was 2012, which saw 147 killings, nearly three times the number in 2002.
"Killing of environmental activists is a hidden problem, and there are systematic trends driving it," Mr Oliver Courtney, a senior campaigner for the London-based GW, told The Straits Times in a phone interview.
"It is competition for natural resources, a lack of transparency on land deals often done behind closed doors, and the expansion of industrial logging and the mining industry," he added.
Indigenous people fighting for their land rights against powerful and often politically connected local and corporate business interests, suffered the most, accounting for 115 dead.
Most of the cases took place in Latin America, and the Asia-Pacific. GW could not obtain enough information on several African countries, so Africa does not figure in the report.
Countries such as Brazil and the Philippines have the worst records, according to the 34-page report.
Between 2002 and 2013, 67 activists were killed and two disappeared, presumed dead, in the Philippines. In only two cases were the perpetrators caught and jailed.
In South-east Asia, Thailand had 16 killings in the same period and Cambodia, 13. In Myanmar, incidents were under reported or could not be verified in time for the report, GW said.
"Never has it been more important to protect the environment, and never has it been more deadly," says the report titled "Deadly Environment: The rise in killings of environmental and land defenders".
"Competition for access to natural resources is intensifying against a backdrop of extreme global inequality," it said.
The 908 deaths were spread across 35 countries, with Brazil accounting for 448 and Honduras 109, followed by 58 in Peru, 67 in the Philippines, 52 in Colombia and 40 in Mexico.
GW believes that there is "significant under-reporting" of these types of crimes in countries such as Myanmar and China, Indonesia's West Papua and in Central Asia.
Just 10 perpetrators are known to have been tried, convicted and punished between 2002 and 2013 - only around one per cent of the overall incidence of known killings. Killers are, however, often just hired guns acting for business interests.
The victims were killed for opposing a range of environmental threats including mining, illegal logging, toxic waste dumping, expansion of biofuel plantations, and construction of large-scale hydroelectric dams.
"The deaths are mostly assassinations of specific individuals, or extrajudicial killings in the context of demonstrations and protest actions," GW says.
"The data shows how indigenous peoples, landless groups and peasant movements are on the frontline of this upsurge in violence. We have documented 92 incidents with 115 victims related to indigenous peoples."
The report concludes by saying: "A more coordinated, concerted effort is required from governments, civil society and international bodies such as the UN to monitor and tackle this crisis as a global phenomenon in its own right."
Said Mr Courtney: "There is excellent work being done by groups in certain countries; what we don't have is a systematic analysis of what's going on at a global level. There are reporting procedures that can hold governments more accountable."
"We feel there needs to be more attention and recognition of this particular problem."