How can civil engineers help combat climate change?

Hi all.

I am a junior civil engineer, my specialty is in traffic and transportation engineering. I also work on drainage, utilities, and structural (Soundwall / parking structure PS&E). I am fortunate to have a well-rounded work environment.

I have always been passionate about the environment in general, and I always think about the environmental impact of my design, even though I have an expert coworker with over 30 years of experience assessing environmental impact of our designs. I live in southern California, so I think about water conservation, capture, retention, treatment, and reuse. I also think about material, although I am constrained by having to balance budget with environmental impact; I can only get away with so much. And, ultimately, the final decision is up to my boss. Luckily, my boss and I have a solid work relationship and have the same mindset with respect to the environment. Obviously he has more constraints, but we always do the max we can get away with.

The question is; how can civil engineers help combat climate change?