The most practical issue is the ecological damage cats cause. Outdoor cats kill billions of birds and small mammals every year, and even indoor cats need clay litter that's strip-mined from the earth, plus a heavy meat-based diet. Dogs, when managed responsibly, don't decimate local wildlife. If you care about sustainability and real climate impact, dogs are the clearly better choice. They also strengthen your bond with nature daily instead of just watching something sleep in a sunbeam. Cats might be easier, but easier isn't better for the planet.