BERLIN (AP) — Leaders from 16 European countries called Friday for greater efforts to curb global warming ahead of international climate talks taking place in Poland next month.

In a joint declaration, presidents and prime ministers from Cyprus to Sweden described climate change as "the key challenge of our time," noting that average global temperatures have already increased sharply since pre-industrial times.

"We have felt the immediate effects as recently as this summer, including in Europe," the leaders said. "Heat waves and scorching fires from Greece to the Arctic Circle claimed the lives of dozens of women, men, and children while eradicating the livelihoods of many others."

The declaration, spearheaded by Austrian President Alexander Van der Bellen, says that while further warming "is a serious threat to peace and stability around the globe," measures to prevent it are both necessary and potentially beneficial to economies and societies around the world.

Negotiators gathering in Poland from Dec. 2-14 will seek to finalize the framework of the 2015 Paris climate accord and discuss setting new, more ambitious goals for 2025.

So far, the targets put forward by the more than 190 countries that signed the agreement are insufficient to reduce greenhouse gas emissions to levels where global warming will remain under 2 degrees Celsius (3.6 degrees Fahrenheit) by the end of the century, let alone the more ambitious 1.5-degree target set in Paris.

"We collectively have the obligation toward future generations to do everything humanly possible to stop climate change as well as to adapt to its adverse effects," the European leaders said in their declaration.

The signatories also include presidents of Germany, Italy and Greece, but not of Poland, which is hosting the upcoming climate talks in its southern city of Katowice.

The Polish government plans to begin the talks with a declaration of its own, backed by as many supporters as it can muster, calling for a "just transition." The phrase is a reference to the idea that workers in carbon intensive industries — such as coal mining — should receive financial support and training for new jobs, but some governments fear it could be used to justify demands for large handouts to industrial countries like Poland.

A slick video released by the foreign ministry on social media this week, portraying Poland as a country striving for a clean, green future, was slated by environmentalists as far from accurate.