Did the Columbian Exchange ultimately do more harm or good, and how much responsibility/credit should Columbus bear for it?

Did the Columbian Exchange ultimately do more harm or good, and how much responsibility/credit should Columbus bear for it? 1)
The research paper will focus on helping students learn to connect actions/decisions, choices, and consequences in decision-making within a relevant historical context. The department has created a list of acceptable topics for instructors to choose from (see below). Instructors may add their own tailor-made topics to the list by submitting their requests to the history department chairman, who willi then submit the topic(s) to the HIST curriculum subcommittee.
2)
The research paper should have at least three main parts: (a) A section where the student provides historical context and background for the topic. (b) A section where the student analyzes a controversial decision made by a relevant historical figure or institution, including all options available to said figure/institution and the various factors that contributed to the outcome of the historical scenario. (c) A section where the student explains the historical significance of the decision that was made.
3)
Minimum paper requirements:
The paper must be a minimum of three pages in length
(excluding the title and works cited pages. The paper must be typed in a 12 point font and double spaced. Students must cite their sources using MLA style. Internal citations are REQUIRED. Each paper must analyze and incorporate a minimum of one primary source and one secondary source; the class textbook may not be used as a source. Failure to meet the minimum paper requirements will result in a failing grade for the assignment.