Japan remains one of the world's worst-performing nations in tackling climate change, think tank Germanwatch said Wednesday.

Japan was deemed the second-worst performer of 57 countries and Taiwan, this year's Climate Change Performance Index report showed.

The report said Tokyo's efforts to reduce greenhouse gas emissions center on reactivating nuclear energy as more or less the only alternative to fossil fuels, "instead of sufficiently promoting renewable energy."

With the top three countries left intentionally blank, Japan placed 60th, down two notches from the previous year. Saudi Arabia was the only country deemed worse.

France, which ranked fourth, was considered the best performer because of its leadership in helping adopt the Paris Agreement on combating climate change last December. It was followed by Sweden and Britain.

The three biggest greenhouse gas emitters in the world — China, the United States and India — placed 48th, 43rd and 20th, respectively.

The index, prepared with environmental group Climate Action Network Europe, is based on several factors, such as levels of heat-trapping gas emissions, the use of renewable energy, and climate policy.