Empathy is a fundamental trait of a great leader.
Because it makes it possible to "read" the very specific wiring of other people's brains. It makes it possible to walk a mile in their shoes, understand how they feel, what they need and ultimately, how you can help them and inspire them to change.
Often technical people think they just have to show the facts for others to change their behaviours or adopt their solutions. Or that they have to show off their technical knowledge with impressive-sounding big words to be credible.
But if you want to lead in sustainability, gone are the days of preaching and just exposing the facts. If that was enough, we wouldn't be in the mess we are right now, since we have known about climate change for decades.
Try changing your attitude before the next meeting with a new client: become curious about them as people, and try to feel what your clients want and feel - even if your principles and values are heading in opposite directions.
Just stop thinking about yourself and think like they are thinking.
Listen more than you are speaking.
Ask yourself (and them): what would make a difference to them?
What do they need and what do they want?
How can you help them get to their targets while keeping the Earth in mind?