At last weekend’s stimulating Bay Area Book Festival, at sessions focused on global warming the audience asked me (and other authors), “What can I do in this time of crisis, especially as Trump withdraws from the Paris climate agreement?”

The answer to the question, “What can I do?” combines working actively with environmental and political groups to ensure just and effective government policies to create a low-carbon economy, and to personally do less damage to the environment by eating less meat, wasting less food, and using much less petroleum-powered transportation.

With the Trump administration abdicating its global responsibilities, action at the individual, state and local government, and company levels will decide the U.S. carbon emissions. People’s daily habits in two areas are especially important in determining our ecological footprint: diet and transportation. Out impact on earth is dramatically reduced if we eat little or no meat and if we do not waste food by eating left-overs and composting scraps. The U.S. is a nation of meat eaters, and averages 271 pounds of animal protein yearly—twelve ounces of meat each day for each person (without excluding vegetarians). This is an enormous amount of meat, and carbon emissions, from our meat diet alone. Only the people of Luxembourg eat more meat.

The other big driver of people’s carbon emissions is their vehicle fuel efficiency and miles driven. If you drive a hybrid or electric vehicle, use public transit, and walk or bike, your carbon emissions are very low. Yet Californians continue to buy gas guzzlers, especially SUVs and pickup trucks. In the San Francisco Bay Area, 130 million miles are traveled each day, or 14.5 miles per person. You can quickly see that fuel efficiency matters—drivers are using 5.2 million gallons of gas daily if cars average 25 miles per gallon, and are using 2.6 million gallons if cars average 50 miles per gallon. Accordingly carbon emissions drop by half. The goal is to use electric vehicles and public transit combined with walking and biking, and to use no gasoline.

We know that individuals alone cannot solve the global warming problem, and together Californians can do much. Fortunately California is moving rapidly ahead with policies to create a prosperous, just, and sustainable low-carbon economy by 2050. Working with our engaged environmental and political groups, we can make sure our local and state governments implement the wide range of clean energy and sustainable agriculture policies to reach the state’s goals.

Californians will provide global leadership on creating a sustainable, prosperous economy that works for everyone. We will not let Trump stand in our way.