The chart above shows the member nations of the G-20 and their leaders. It was established in 1999 as a way to stabilize the world economy (which would be beneficial to all nations). These powerful economic entities can have a significant effect on the world economy, since they control 4/5 of the gross global product and 3/4 of the world trade. It was originally only attended by the finance ministers of each entity, but in 2008 the heads of state started attending (due to the economic problems posed by the recession).
But to be effective in stabilizing the world economy, the G-20 nations need to act together. Unfortunately, there is now a fly in the ointment -- Donald Trump. Trump is taking actions that go against the purpose of the G-20.
Recently, Trump notified the world that the United States would pull out of the Paris Agreement on global climate change. Global climate change is an issue that will have a growing effect on the economies of all the world's nations -- and having the United States not participating puts the effort to control global climate change in serious doubt (since the U.S. is the largest user of fossil fuels and second in production of greenhouse gases).
Trump has also decided that he wants to "renegotiate" the trade agreements the U.S. has with other entities -- claiming they are unfair to the United States. And he has even said he might pull the U.S. out of those trade agreements if they cannot be redone to favor the United States. There is little doubt that a U.S. abandonment of the trade agreements would be detrimental for the world economy.
In other words, Trump is acting against the very purpose of the G-20. Instead of joining the other nations to stabilize the world economy, he is acting to destabilize it. Donald Trump is emerging as the G-20's (and the world's) biggest problem.
