Changing to vegetarian diet and driving less had the biggest impact.
Also, reduce then reuse then recycle in that order.
Side topic, but meat these days is quite expensive if you really take it from a quality manufacturer ( Bio meat in Germany costs 3 times more than the "regular" one ). You can imagine what kind of meat you get if you don't have to dig deep into your pocket for a meal.
As a “carnivore” or at least omnivore, most dishes feel like they’re either missing some part (i.e. “dinner is just a salad”) or trying to imitate a meat product.
Legumes like lentils and chickpeas are also very filling, and you can easily make them into amazing curries with very little effort by slightly overcooking the lentils, pan toasting the chickpeas, mixing them together with some coconut milk and whatever spices go with your palate. I like to use curry leaves, garlic, cumin, thai green chiles, salt, and onion as a base. The fat from the coconut milk will nicely improve the texture of the lentils (which have too much protein and fiber relative to fat to have the right texture) and as it cooks down you'll get something akin to a coconut milk korma or a close enough approximation that you can take it from there and just have it with rice or blanched spinach.
I'm also a really picky eater, and it took about that amount of time for my palette to start to change, to the point where I now really enjoy salads, mushrooms, tofu, and well-cooked veggies.
Changing a pallet is hard, it's OK to do it gradually, and it's OK to experiment and find setups that work for just you. I'm still working on softer veggies like baked beans; everyone says they're really healthy, but I saute about 90% of the veggies I eat. There's something about steamed or boiled veggies that just grosses me out.
But there were other foods I thought I'd never like before, and it's been really interesting especially over the last 4-5 months to go back and try foods that I dismissed before and discover that I suddenly like them a lot more.
Aim for reducetarian and go with the flow. Experiment, and think in terms of possibilities; not limitations. That being said, artificial restrictions can aid as extrinsic motivation, stimulating you to experiment. It could also lead you to conclude that it is too <fill in> (e.g. boring), thereby giving up, while the reason is that you did not put in enough thought, time, and -ultimately- effort.
For no particular specific good reason (apart from having lived as full-time vegetarian for ~10 years, vegan ~2 years and reducetarian for another ~10) I can recommend the book Plenty by Yotam Ottolenghi. 
What a waste. I hope that at least most of it is long haul trucking or something with personal value like a vacation, rather than just commuting.
9800 per capita should be completely unsurprising to any American. If all you did was drive to work, it'd be a mere 40 miles per workday (5 days a week, 50 weeks).
Non-Americans might be surprised about it. But let me be clear: driving is the backbone of American society. Always has been. The classic video game Oregon Trail is about Americans making one long commute across the entire country, so they could find better jobs. Which honestly explains a lot about Californians: our ancestors traveled the whole of the United States to get here, what's a short 2 hour commute to work on the 405 every day?
Our country is HUGE, almost all of it is habitable, and we have a sprawling road system. We have the option to work where it's most profitable, and live where it's most comfortable. And boy do we take advantage of that.
Good or bad, that's the U.S., so I hope people aren't too surprised when they learn that we've been burning a lot of gasoline in our cars. And also perhaps why we have such a pro-oil/coal culture.
Even when looking at the global numbers and taking into account countries with less efficient systems, the global total is still less than 15% of all greenhouse emissions. 
Intensive breeding at larger scale has an environmental impact, same as all human activities at large scale. And eating too much meat may not be great for health.
The title is not misleading. Local meat, fish & dairy are worse all around than far-away vegetarian foods.
This is not an argument for or against being vegetarian, just a more or less indisputable measurement of food production.