Cardano ensures network sustainability through its focus on energy efficiency, resource optimization, and long-term viability. By utilizing a Proof of Stake (PoS) consensus mechanism, Cardano reduces energy consumption and carbon footprint compared to traditional Proof of Work (PoW) systems, making it more environmentally friendly and sustainable. Additionally, Cardano's treasury system and governance mechanisms enable stakeholders to allocate resources and fund initiatives that promote the growth, development, and resilience of the network over time.