In 2012, recognizing the threats posed by environmental degradation, the United Nations Human Rights Council appointed an independent expert to study how countries' human rights obligations are connected to promoting "a safe, clean, healthy and sustainable environment."
John Knox, a law professor at Wake Forest University, was appointed the first special rapporteur on human rights and the environment. His three-year mandate was extended in 2015.
This year, with killings of land activists increasing worldwide, Knox helped launch a web portal, www.environment-rights.org, with information and resources in English and Spanish. In March, at the Human Rights Council, he will present guidelines for states on their obligations to protect environmental rights, including ensuring that people most vulnerable to harm have access to effective remedies.
Knox spoke to The Times about the threats facing environmental defenders. His comments have been edited for length and clarity.
Why is it such a dangerous time for land activists?
There are basically three reasons that come together. One is simply there's greater demand for the natural resources these activists are trying to defend. Many of these countries are pretty rich in natural resources — minerals, lumber, land that can be used for palm oil plantations or other industries.
And that leads to the second factor, which is that many of the groups living in these areas are vulnerable for other reasons. They are rural, they don't have much money, they're already marginalized in their own countries and don't have a standing in the political debate.
The last is the absence of effective rule of law, either in the country as a whole or in a region. A common denominator is the courts, police and law enforcement mechanisms are ineffective. What I see over and over again is that these murders and other kinds of harassment take place when there's impunity.
Are more activists being killed or is there just more awareness of the issue?
It's hard to know. Personally, I think it's likely that it has been going on for a long time, and the numbers in some ways seem to be going up because groups like Global Witness are doing a better job of reporting what's happening.
Part of how you can see that is there are countries that seem to have low numbers of killings, but in large part that's simply the effect of not knowing what's going on in those countries.
You mean like China or Russia?
I'm not going to single out any countries, but I do think that in countries that have the highest numbers of killings, there's enough space for civil society to find out and report on it. That's true of Brazil, the Philippines, some Latin American countries.
Having said that, I agree with Global Witness that there does seem to be an increase in these murders, and other types of harassment, because of increasing demand for resources.
It seems like many of the killings occur in places inhabited by indigenous peoples.
That is what makes the struggle so desperate. They're fighting not just for a healthy community but also for their culture and their way of life. Many of the most vulnerable communities are faced with a kind of existential threat: If they give up their ancestral territory, their culture dies.
What have you learned about impunity rates for environmental murders?
In Global Witness' first report, when they went back over 12 years' worth of data and over 900 deaths of environmental and land defenders [from 2002 to 2013], there were  cases where perpetrators were arrested, tried and convicted. If that's even close to accurate, that's 1% — essentially a green light to allow people to kill environmentalists with impunity.
What's the link between these killings and corruption?
One reason why governments, especially at the local level, fail to take adequate steps to protect people is that government officials themselves are somehow being paid off or are in collusion with powerful economic interests. Another is that often in these countries, the land defenders are somehow seen as standing in the way of progress, whether it means building this dam or awarding this mining concession.
That's fundamentally mistaken. The only type of economic development that makes sense is sustainable development, and often these environmentalists are the ones asking whether these projects are truly sustainable. If you don't ask those questions, you end up with projects that down the road will hurt the countries' economies. So these defenders, they should be thought of as heroes, rather than obstacles to state interests.
How are governments responding?
There are some promising developments. One is that conceptually, thanks largely to Global Witness and other environmental organizations, like Front Line Defenders, these deaths are increasingly seen as part of a global pattern instead of a series of local events.
Several men who were shot by security guards outside a Guatemalan mine are suing the Canadian mining company, Tahoe Resources, in Canada, where legal protections are stronger. Are you seeing such attempts to take international companies to court?
There have historically been efforts like that, but often they run into legal problems in the corporations' home countries. In the U.S., the Supreme Court effectively stopped these efforts by ruling that U.S. statutes are only concerned with activities in the U.S. [in a 2013 case involving Nigerians who tried to sue Royal Dutch Petroleum over killings at a Shell oil plant in Nigeria]. There are lots of hurdles to overcome in bringing cases in home jurisdictions, but we continue to see them brought.
Last year, the International Criminal Court prosecutor issued a statement saying they would be open to considering cases of land grabbing and massive environmental harm as crimes against humanity, and therefore within their jurisdiction. That would be a big development if the ICC started such cases — a real shock to the system in terms of overcoming impunity at the international level.
Follow @SBengali on Twitter for more news from South Asia