The largest outbreak of Ebola on record has sparked intense second-guessing of authorities around the world, and lack of trust in public institutions was a major factor in its spread through West Africa, wrote Laurie Mazur last month.

A series of executive orders signed by President Obama since his first year in office requires all federal agencies to begin planning for climate change and produce an updated adaptation plan by May of this year. The Pentagon is a little late, but today they released their second-ever climate roadmap.

What if it’s not increased scarcity that’s most disruptive about climate change, but variability? Cullen Hendrix explains how new research on water conflict suggests that’s the case in last month’s most popular story.

Much of the time, discussion about climate change is focused on the future – How bad will it be? Will it lead to more conflict? Who will be most vulnerable? But it is in fact a current phenomenon. The climate system is already, for all intents and purposes, irrevocably changed and millions of lives have been changed along with it.

It’s been 20 years since the Environmental Change and Security Program was founded to shed light on the new security issues of our times, so in honor of this anniversary, we’ve rounded up the 20 most popular stories of all time.

We started the last top 10 post tracking the dramatic battle over Iraq’s Mosul Dam and the most popular of August took a closer look. Cameron Harrington and I explain that this isn’t the first time water has played a major role in the fighting, while also exploring ways it could be a peacemaker.

The fight for control over “the most dangerous dam in the world” is raging.

Since its capture by Islamic State (IS) militants on August 7 and subsequent attempts by Iraqi government and Kurdish forces to take it back, Iraq’s Mosul Dam has been one of the central components of the government’s surprising and rapid collapse in the country’s northern and western provinces. In fact, one might see the capture of the Mosul Dam as the moment IS ascended from a dangerous insurgent group to an existential threat to Iraq as a state.