BONN, Germany (AP) — As negotiations at the global climate conference in Bonn, Germany, draw to a close Friday, here's a look at which steps will be taken in the coming years to further international efforts to curb global warming:

— Dec. 12, 2017: French President Emmanuel Macron has invited more than 100 world leaders to Paris for the second anniversary of the landmark climate accord forged in the city in 2015. President Donald Trump, who has said he wants to withdraw from the agreement, hasn't been invited to the "One Planet Summit."

— 2018: Next year's global climate talks take place in Katowice, Poland, from Dec. 3-14. In order for officials to finalize the rulebook there, preliminary meetings will have to be held during the course of the year. These low-level encounters will include the Talanoa Dialogue, a Fijian-inspired process in which countries start to take stock of what's been achieved so far under the Paris agreement and consider what more can be done. The talks in Katowice will be strongly influenced by the U.N. scientific panel's October report on whether the most ambitious goal of keeping global warming at 1.5 degrees Celsius can be achieved.

— 2020: If the U.S. goes through with its threat to withdraw from the Paris accord, the earliest this could come into effect would be on Nov. 4, 2020 — shortly after the next American presidential election. Countries that are party to the Paris agreement have until 2020 to submit new or updated plans, known as Nationally Determined Contributions (NDCs), on what they are doing to reduce emissions and adapt to climate change.

— 2023: Eight years after the Paris accord countries will for the first time conduct a full and formal review of what's been achieved to date, known as a global stock-take. The process is meant to be repeated every five years.

— 2030: Many countries have set themselves substantial emissions reduction targets 15 years from the Paris accord. The European Union, for example, wants to cut its emissions by 40 percent from 1990 levels, though some countries including Germany are aiming for a 55-percent reduction.

— 2050: Climate scientists calculate that the world economy will have to go "carbon neutral" by the middle of the century if the Paris goal of keeping global warming well below 2 degrees Celsius (3.6 Fahrenheit) is to be achieved. That can either be done by ending all use of fossil fuels or by finding a way to remove carbon dioxide from the atmosphere at an industrial scale.