Sustainable energy refers to energy that is produced and consumed in a way that meets present needs without compromising the ability of future generations to meet their own needs. This includes energy sources that are renewable, such as solar, wind, and hydropower, which can be replenished naturally. The shift towards sustainable energy is crucial for reducing greenhouse gas emissions and combating climate change. By investing in sustainable energy technologies, societies can create a cleaner environment, enhance energy security, and promote economic growth through green jobs and innovation.