The phrase "to change the scenario" means to alter or transform the current situation or circumstances in order to create a different outcome or result. Full definition
Early used a moderate climate change scenario of 2 degrees Celsius warming by the end of the century. (scientificamerican.com)
With changing scenario of society, now you can step forward with your new thoughts and stop thinking that dating is a game of young people. (over50dating.org)
This is roughly the rise predicted by climate change scenarios in which humans go on burning fossil fuels, to deposit ever more carbon dioxide in the atmosphere. (climatenewsnetwork.net)