While climate performance varies greatly, a report finds that none of the countries surveyed were currently on a path compatible with the Paris climate goals.
The United States and Saudi Arabia are among major polluters showing "hardly any signs" of reducing their greenhouse gas production, a global assessment of countries' emissions trajectories said on Tuesday at United Nations climate talks.
The Climate Change Performance Index (CCPI) measures the emissions, renewable energy share and climate policies of 57 countries and the European Union.
It found the US ranks last, followed by Saudi Arabia and Australia, although several countries did report falls in emissions last year, largely due to an industry-wide fade out of coal.
While climate performance varied greatly — even within the EU, with Sweden leading the way — the report found that none of the countries surveyed were currently on a path compatible with the Paris climate goals.
The 2015 accord saw nations agree to work towards limiting global temperature rises to "well below" two degrees Celsius above pre-industrial levels.
US President Donald Trump says he plans to withdraw from the global plan to reduce emissions.
China, the world's largest single emitter, was found to have taken "medium action" due to its high investment in renewables. However the index warned that Beijing could slump to the bottom rungs if it follows through on its plan to continue building coal-fired power plants.
Ursula Hagen from the environmental watchdog Germanwatch, who co-authored the accompanying report, said both the US and China were "at a crossroads" on climate.
"The index shows signs of a global turnaround in emissions, including declining coal consumption. However, several large countries are still trying to resist this trend — above all the USA," she said.
"Much will depend on further developments in China and the elections in the USA."
Delegates are gathered at the COP 25 in Madrid to devise ways of putting the Paris plan in action, but key sticking points remain over emissions trading schemes and how the fight against climate change is funded.
"This science-based assessment shows again that in particular the large climate polluters do hardly anything for the transformational shift we need," said Stephan Singer from the Climate Action Network.
He said nations need to implement "deep emissions reductions to curtail the run to potentially irreversible climate change."