Being green is easy for these 5 countries

Flickr / Carlos Andrés Reyes

Every Earth Day, the world celebrates efforts to improve the environment across the globe. And each year, Yale's Environmental Performance Index (EPI) ranks the top-performing countries for the environment, based on how well they've fared at protecting human health and vulnerable ecosystems.

Perhaps unsurprisingly, the top five countries this year were all European.

The EPI creates index by giving each country a score out of 100 that's based on a number of specific metrics. The individual scores are averaged for each country to create the rankings. 

See below for the 5 best performing countries on the 2016 report: 

#1 Finland: 90.68

Finland took the top spot on the index, scoring 90.68. It ranks fourth in health impacts, eighth in fisheries, and top 20 in climate and energy, biodiversity and habitat, water resources, and air quality.

Though Finland is one of Europe's most forested countries, it didn't score well on the agriculture and forests categories coming in at 87th and 106th respectively. 

According to the EPI, Finland has made a "societal commitment to achieve a carbon-neutral society that does not exceed nature's carrying capacity by 2050." 

#2 Iceland: 90.51

Iceland came in a close second on the index, scoring 90.51. It ranks third in health impacts, as well as climate and energy, and fourth for air quality.

Iceland's top performance is a function of its unique geology — around 25% of its power is produced geothermally, more than anywhere else on Earth, according to the EPI. 

And 100% of Iceland's electricity comes from renewable sources, like wind, and hydro-power, according to Iceland's National Energy Authority. 

#3 Sweden: 90.43

Sweden came in a close third, scoring 90.43. It ranks fifth in health impacts, tenth in climate and energy, and top 20 for both water and sanitation, and water resources. 

Across the board, Sweden earned almost perfect scores on drinking water quality and wastewater treatment, according to the EPI. 

Like Finland, Sweden performed poorly on forests — largely due to unsustainable logging practices.