Groups that monitor countries' performance in tackling climate change say Sweden remains top of the league, while the United States has dropped in the index.
The Climate Change Performance Index released Monday on the sidelines of a U.N. summit on global warming has no countries in the top three ranks because none does well in all categories assessed.
But Sweden took the best spot, fourth, as last year, while Morocco's efforts to ramp up renewable energy pushed it up a notch to fifth place.
The European Union as a whole rose from 21st to 16th place, but its biggest economy, Germany, fell from 22nd to 27th because of its reliance on lignite coal, a big source of greenhouse gas emissions.
The New Climate Institute, Climate Action Network and Germany, which produced the index, said the U.S. dropped from 56th to 59th place due to high emissions and poor ratings for the federal government's policies.
Saudi Arabia came last, in 60th place, partly due to its obstructive role during international climate negotiations.