Respect for the interdependent web of all existence of which we are a part.There has been a suggestion that the word respect be replaced with reverence in order to better emphasize the responsibility each human has toward our environment.
The UUs are a very diverse group, embracing both the traditionally religious and the largely secular. Reverence, while certain an appropriate word for some UU members, has fairly overt religious connotations that seems contrary to the UU's general outlooks of inclusiveness.
And if this sounds like a lot of hubbub over nothing, I'd like to remind you of the continuing controversy over what the heck we're supposed to be calling Pluto. A couple years ago it was "demoted" from planet to dwarf planet, and the latter term was only decided upon after consideration of multiple alternative terms such as Kuiper Belt object. In addition, Pluto was also classified as a plutoid, denoting dwarf planets in the Kuiper Belt. It was hoped that naming a whole classification after Pluto might mollify the Pluto-supporters, some of whom organized demonstrations.
Reality hasn't changed, Pluto is the same small, round ball of ice and rock that it has been for millions of years. All that has changed is the words describing it. Words matter. Perceptions matter. What looks like a small change to one person can represent a major shift to another. Language is a powerful thing.