During a peaceful action carried out at the thermoelectric power plant in Tula, Hidalgo, in occasion of Earth Day 2021, Greenpeace Mexico raises a hot air balloon with a message reading "Excess Pollution", to paraphrase the text often used in industrialized food. The activity is to warn that fuel oil is being burned in this plant with a 3.9 percent sulfur content by mass, exceeding the maximum limit established by the Official Mexican Standard NOM-016-CRE-2016, of 2 percent. Fuel oil is one of the fossil sources that emits the most greenhouse gases per kWh, 898gCO2.