There are two sides to this question.
The people concerned about an environmental crisis quote the 97% of studies in juried scientific journals which say there is a crisis and it is created by human activity. The other side of the argument either thinks it is a hoax, or if there is warming, it?s not caused by human activity, or the suggested remedies are too costly. This conflict is no amusing parlor game question with no real world consequences.
The recently elected administration has supported the "hoax" answer to the question. The newly indicated person in charge of the environmental staffing for the Environmental Protection Agency , Myron Ebell, is a "hoax" supporter. The new administration has indicated that it will withdraw from the Paris Accord, which is a pact of over 190 nations pledged to keep the rise in world temperature less than 2 degrees Celsius above pre-industrial levels. China, India and the US are the worst contributors to the emissions problems. The commitment of the USA had a big impact on the Chinese agreement to the Accord. Every nation has some "hoax" backers, concerned about the costs of regulating fossil fuel industries. Without the US commitment there could be the collapse of the Accord with major withdrawal by countries where the economy will be affected by limits on fossil fuels.
Pope Francis , in drawing attention to the environmental crisis, calls us to an even broader commitment beyond controlling warming. In his encyclical "Laudato Si!", he speaks of pollution, waste, and the throw away culture. He also talks about the issue of the availability of fresh water, and he warns of how all these factors interact to the detriment of the poor.