These 5 countries are the worst environmental offenders

Eritrea narrowly beat Somalia to take the 179th spot. 66% of Eritreans live below the poverty line, and the country suffers from droughts and rampant famine.

Eritrea ranks 160th in health impacts, 105th in air quality, 168th in water and sanitation, and 165th in biodiversity and habitat.

Conflict is also an ongoing problem in Eritrea, and its army is often involved in border skirmishes with neighboring Ethiopia and Djibouti.

But Eritrea is also rich in mineral resources, and the government hopes to build the economy through the mining sector.

Madagascar took the third-lowest spot. Similar to Somalia, Madagascar is largely undeveloped, and is among the poorest countries in the world.

Madagascar ranks 178th on health impacts, 177th in water and sanitation, 130th in air quality, and 132nd in biodiversity and habitat.

Despite Madagascar's low rank, Madagascar scored 20th on agriculture, likely because most Malagasies farm through traditional methods.

Yet Madagascar is also one of the most biodiverse countries on the planet — claiming unique species found nowhere else on Earth — so protecting its environment from illegal logging operations is crucial.

Niger came in 177th. Niger consistently ranks among the lowest countries on the UN's Human Development Index, and it suffers from massive drought and desertification.

Niger ranks 180th in health impacts, 179th in water and sanitation, 168th in water resources, and 159th in air quality.

Niger's sanitation problems are widespread, and many in rural areas lack access to toilets and clean drinking water.

But the country is making progress: over the past 20 years, Niger's farmers have planted and maintained over 200 million new trees, in an effort to combat desertification.

Afghanistan narrowly beat Niger for the 176th spot. Afghanistan has struggled with conflict for decades, so protecting ecosystems and improving key health infrastructure has taken a backseat.

Afghanistan ranks 161st for water and sanitation, 139th for health impacts, and 178th for biodiversity and habitat.

Deforestation continues to be an ongoing problem in Afghanistan, as many impoverished Afghans rely on wood-stoves to heat their homes during the brutal winters. As well, nearly one-third of all Afghans lack adequate nutrition.