Today in our environmental science lecture, we will discuss the impact of urban farming. One key point is that rooftop gardens can reduce a building's energy consumption by up to 25% because they provide natural insulation. However, the initial cost of setting up such a garden is quite high, often exceeding $10,000 for a medium-sized roof. Despite this, many cities offer subsidies to encourage this practice. For example, in New York, a program covers 30% of the installation costs for community gardens. Additionally, these gardens help manage stormwater runoff, which can reduce pressure on city drainage systems during heavy rains.