The protesters' symbol was a clock to signal to those meeting at the United Nations climate change conference (COP24) that time is running out if the world is to limit global warming to within 2 degrees Celsius (3.6 degrees Fahrenheit). Negotiations at the COP have been tough, with disagreements on financing for developing countries and on how states should report their emissions cuts.

Some marchers made giant puppets, including of Brazil's president elect, Jair Messias Bolsonaro, to protest the leader's climate policies. Bolsonaro has threatened to follow US President Donald Trump and withdraw his country from the Paris climate agreement. Bolsonaro has also talked about loosening protections for the Amazon rainforest — the Earth's green lungs.

About seven million people worldwide die prematurely due to air pollution every year. Poland's air quality is particularly bad because of the country's dependence on coal for electricity and heating. Some protesters decorated pollution masks to make a statement about Poland's coal policy. During the COP, the country's president said there was no intention to phase out coal.

Some groups, like the International Atomic Energy Agency, are promoting nuclear energy as an alternative to fossil fuels. It would provide a stable and greenhouse gas-emission-free energy source, says the IAEA. A number of protesters turned up to advocate against nuclear, because there is no good way to deal with the radioactive waste it produces and because it is potentially unsafe, they say.

Sustaina Claus arrived at the climate march with his Christmas elves to preach the message of sustainability. The environmental activist says we need to stop overconsumption if we are to stop climate change and protect the planet's resources. Instead of buying mountains of gifts for your loved ones at Christmas, "you should give the gift of you."

NGOs said a number of environmental campaigners were refused entry at the Polish border or deported from the country, having been deemed a "threat" to national security. Climate Action Network, an umbrella group of climate groups, called the actions worrying. A spokeswoman for Poland's border guards said she could not say whether the refusals were connected to the COP, according to Reuters.

Climate activist Lander Wantens cycled over 1,000 kilometers from Belgium to Katowice for the protest and to deliver a message to delegates to do more to combat climate change. He hopes that if the negotiators see "four guys from Belgium are crazy enough to bike to the climate summit in Poland in winter, maybe that's a signal that they have to work on an ambitious climate agreement."

"Why study, if our future is being destroyed?" This sign features a sentiment shared by increasing numbers of German students, who have joined young people worldwide in using Friday school strikes to call for action on climate change. The movement was inspired by 16-year-old Swedish activist Greta Thunberg, who began her protests alone in front of the Swedish parliament in August 2018.

With the 2015 Paris climate accord, nearly all of the world's countries committed to limiting global warming to well below 2 degrees Celsius, preferably 1.5 degrees (2.7 degrees Fahrenheit), by 2100. The hope is that this target will prevent the worst effects of climate disasters. Concerned by the dire predictions from climate scientists, more and more people have called for immediate action.

Despite urgent warnings, politicians have dragged their heels on important climate decisions. It's become clear that Germany will miss its targets for 2020. Climate protection was an important factor in the European elections in late May, with the Greens winning more than 20% of the vote in Germany alone, more than double previous results. Among 18-24-year-olds, 34% backed the party.

Germany's climate movement is fighting on many fronts. In recent years, activists have fought to preserve Hambach Forest in the western state of North Rhine-Westphalia, building treehouses to prevent the old-growth forest from being felled to make way for the mining of lignite, or brown coal. Energy giant RWE has launched legal action, and police have cleared the camp several times.

In September 2018, a few days after the camp was removed again, a court ruling suspended the clearing of the forest until late 2020, after a lawsuit by environmental group BUND. RWE has argued that the forest has to be cut in order to ensure the coal necessary for Germany's electricity supply. Around 50,000 activists celebrated the victory.

Protests organized by groups such as Ende Gelände have increasingly been making headlines. Thousands of young activists have come out to staged events, blocking railway tracks used to deliver coal to power plants near Cologne and occupying huge coal excavators, as seen here in the open-pit mine in the east German town of Welzow in 2016.

In January 2019, after seven months of negotiations, a coal commission set up by the federal government to work out Germany's plans to phase out coal power released its findings. It recommended that Germany should continue coal mining until 2038, at the latest —far too late for the country to meet the targets of the 2015 Paris climate accord.

An increasing number of young people in Germany are demanding that the government find a way to meet the 1.5-degree target. The emerging Fridays for Future movement has been getting support from longtime environmentalists, teachers, academics and parents. They have called for all German coal-fired power plants to be shut down by 2030, and for renewable energy initiatives to be vastly expanded.