WARSAW, Poland — Polish trade union leaders and government officials at a climate conference called Thursday for nations to protect industrial jobs and be given the freedom to choose their own approaches to reduce greenhouse gas emissions.

The two-day meeting that opened in Katowice aimed to work out the positions of Poland's trade unions and industry before an international climate summit in December taking place in the industrial city.

Poland chose to host the COP-24 summit in Katowice to show how this former coal-mining city has been turned into an environment-friendly one in the almost-three decades after the collapse of communism and after Poland joined the European Union in 2004.

At the Dec. 3-14 summit, more than 190 countries taking part in the 2015 Paris Agreement are to work out a rulebook for implementing the landmark climate accord.

Participants at the Poland conference said nations should be allowed to choose their own ways of cutting carbon emissions in accordance with their industrialization and reliance on fossil fuels. They said developing economies should not be forced to cut jobs.

"Those member countries in Europe that have a chance for a modern development and for modern industry, they should get support, on the condition it really is modern industry that will preserve the region's jobs," Deputy Energy Minister Grzegorz Tobiszowski said.

Since 1990, Poland has cut over 300,000 coal mining jobs, to some 83,000 currently, and has also scaled down coal extraction to some 65 million tons from 147 million tons. However, the industry remains one of the major employers in Poland and consecutive governments have vowed to protect it, while still modernizing it and making it more environment-friendly.

Some 80 percent of Poland's energy comes from coal, some 15 percent comes from renewable sources and 5 percent is from gas. By 2030, the government has pledged to cut coal to some 49 percent of the country's energy mix.

Tomasz Rogala, the head of the European Association for Coal and Lignite, said that last year the EU imported 173 million tons of coal, an amount that could have provided some 175,000 jobs in Europe.

Among the issues for the two-week summit in December are how to ensure transparent monitoring of what countries do to cut their global emissions and the methods used to take stock of what countries have achieved.

It is also expected that the governments will hear that their current national pledges won't be enough to keep global warming below 2 degrees Celsius by 2100, and should therefore raise their ambitions.

While U.S. President Donald Trump has threatened to pull out of the 2015 Paris accord, the rest of the world remains committed to the deal.