Identify the Assumption in Climate Change Argument

In a well-researched article, environmental scientist Dr. Carla Johnson argues, "The reduction of greenhouse gas emissions is the only effective method for combating climate change. Therefore, if governments globally significantly increase their regulations on emission levels, we will see a measurable decline in global temperatures and a corresponding decrease in climate-related disasters." While her conclusions seem logical, it is crucial to examine the assumption that underpins her argument.