KATOWICE, Poland — A dozen Catholic pilgrims have arrived at an ongoing U.N. climate summit in Poland after walking hundreds of miles across Europe.

The pilgrims were greeted Monday by the head of the U.N. climate office, Patricia Espinosa, who thanked them for raising awareness of the impacts of climate change.

Joanna Sustento said her parents, brother, sister-in-law and 3-year-old nephew were killed in Typhoon Haiyan, the 2013 typhoon that devastated the Philippines. Scientists say a warmer world makes for stronger hurricanes.

Sustento said: “I hope that we do not wait for another catastrophe to happen, for us to really fully commit and take action on climate.”

Some of the pilgrims spent more than two months walking to Katowice, Poland from Rome, covering a distance of nearly 950 miles.

Meanwhile, the president of the U.N. climate talks says their success lies with the determination of almost 200 participating nations, not with him.

Poland’s Deputy Environment Minister Michal Kurtyka was criticized Monday by the environmental group Greenpeace International, which said he was not doing enough to ramp up the meeting’s ambitions to curb global warming.

Kurtyka told a news conference at the talks’ venue in Katowice, that their success is in the hands the nations.

He said the role of the presidency is to “make sure that the (negotiating) process is transparent, is inclusive, is taking everybody on board.”

He said the presidency was doing its utmost to build bridges and that his “deepest wish” was for success.

“It is in the hands of parties and it will be a success of (the) parties or it will be our collective failure,” Kurtyka said.

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.

Some 415 asset managers, including major pension funds and insurance companies, are calling on governments to phase out coal-fired power plants and put a meaningful price on carbon to help tackle climate change.

The funds, with over $32 trillion in assets, issued their appeal Monday as ministers gathered in Katowice, Poland, for the second week of a U.N. climate summit.

Burning fossil fuels such as coal is a major source of the greenhouse gas carbon dioxide, and scientists say it needs to end by the middle of the century to keep global warming below 1.5 degrees Celsius.

The United States has announced it is pulling out of the 2015 Paris climate accord. It is hosting an event at the U.N. talks to promote innovative fossil fuel technology.