Proponents of the Baltimore plan said the aim is to help the planet, but also communities that are eager for investment and cleanup. Shashawnda Campbell, of the South Baltimore Community Land Trust, said the plan is especially important as so many of the city’s neighborhoods get what she called undeserved criticism for dirty streets and alleys. They are the product of illegal dumping and unfair evictions, and the plan would help residents keep them clean, she said.