In 2018 the Gulf coast of Florida suffered extensive damage from harmful algal blooms (HABs), from as far north as Clearwater Beach south to Naples. The bloom lasted nearly a year, picking up in intensity during the late summer months. HABs occur when conditions such as reduced salinity, higher water temperatures, light saturation, and currents cause rapid growth of algae in coastal areas or lakes (NOAA 2018). Along the Gulf Coast the predominant species of algae in HABs is the dinoflagellate "Karenia brevis," which releases brevetoxins that can cause massive fish kills and result in the death of manatees, sea turtles, and seabirds. Humans can become ill by breathing in the toxins or by eating contaminated shellfish. In addition, HABs deplete the dissolved oxygen in the water, leading to the deaths of a wide variety of marine organisms (Pierce and Henry 2008). The lesson presented in this article models the effects of global climate change on the growth of algae. In addition to it being inquiry-oriented, it is place-based, which provides the opportunity for students to explore the effects of global climate change on their own lives, communities, and regions. Place-based education can support environmentally responsible behavior (Cheng and Monroe 2012) by increasing students' willingness and ability to ask questions and take action related to their surroundings. The lesson was developed part of an National Science Foundation-funded project to produce climate change education materials that could be incorporated into an existing high school marine science course. The goal is for students to leave the classroom with an understanding of factors contributing to algal blooms, as well as motivation to pay attention to local environmental and business regulations.