What action can help decrease global warming?

Turning off your lights when they are not in use is an effective action to help decrease global warming because it reduces energy consumption. When lights are left on unnecessarily, it contributes to higher electricity demand, which often comes from the burning of fossil fuels like coal, oil, and natural gas. This combustion releases greenhouse gases into the atmosphere, exacerbating climate change. By being mindful of energy usage and turning off lights when they are not needed, individuals can significantly lower their carbon footprint and promote more sustainable energy practices.

The other options involve actions that would either increase energy use or have no significant impact on global warming. Keeping the air conditioning on high or leaving a freezer door open would both waste energy, contributing further to greenhouse gas emissions rather than reducing them. Eating more ice cream does not address energy consumption or emissions, making it an unrelated choice in the context of reducing global warming.