There was a moment of hesitation when I first learned about the nature of Lake Kivu, one of the African Great Lakes, shared between Rwanda and DR Congo. Somebody said something about deadly explosions or eruptions and I wasn’t looking for any of that. I just wanted to get out of Kigali for a while, not because I didn’t like it, but because I did. A little too much. Its comfort had contributed to my inertia and laziness. But I knew better. I knew Mini-Rwanda was a nature-giant worth getting to know.
"Somebody said something about deadly explosions or eruptions and I wasn’t looking for any of that."
The Rwandan government had just priced up Gorilla trekking to more than twice of what it cost in neighboring DR Congo and Uganda, where I was headed next. Moreover, having seen many fascinating animals for free or for very little money made $ 1,500 USD for one hour with the Gorillas seem steep, even for a big conservation fan. So the lake then. But deadly eruptions? This called for the kind of reading up I usually like to forego before going.
It turned out that Lake Kivu is one of only three lakes in the world that undergo so called “limnic eruptions,” the other two being Lake Nyos and Lake Monoun in Cameroon. These bodies of water contain large amounts of CO2 and in the case of Lake Kivu also methane. Lake Monoun and Lake Nyos did erupt and release deadly CO2 clouds in 1984 and 1986 respectively, killing nearly 2,000 people and even more livestock through asphyxiation. The subsequent installation of degassing pipes at both lakes is supposed to keep limnic eruptions from reoccurring in the future. But the implementation of a similar project is considered too costly for the much bigger Lake Kivu, where geological evidence of mass extinctions suggests that such overturning events happen roughly every thousand years; and contrary to its smaller Cameroonian equivalents, a limnic eruption of Lake Kivu would put the lives of millions at risk.
"Upon my arrival to Kibuye I found a placid and beautiful Lake Kivu and time to ponder the question why people live in areas with such disaster-potential."
Who was I not to visit this explosive lake for a couple of days, when millions spent entire lives there? Upon my arrival to Kibuye I found a placid and beautiful Lake Kivu and time to ponder the question why people live in areas with such disaster-potential. Lake Kivu is an obvious candidate to raise this question, since the combination of a rather short thousand-year eruption interval and millions of people living nearby render a catastrophe almost inevitable. Coming to think about it though, it might be mostly the ghastly thought of dying so unconventionally – through asphyxiation by lake – that makes voluntarily living there inconceivable at first. After all, people put up with odds that are much worse in places many of us would die to live in: like in and around the Caribbean, where hurricanes cause annual mayhem; or in California, where the state-wide average risk of a 6.7+ magnitude earthquake within the next 30 years is >99%.