What can academics and students do to reduce racism in academia?
One of the forms of racism that UK universities suffer from is that they use unfiltered student opinion to inform hiring as well as evaluation of academics. Academics with foreign accents or unfamiliar (or particularly formal) appearances that the students don't like then suffer.
Interestingly this form of racism is widely understood and largely eliminated in the retail sector where no one would be allowed to choose the race of an employee based on the preferences of their customers. It is also a form of racism we could easily eliminate from academia if we honestly faced up to it.
I think the point of my answer has been slightly lost (see comments below). The point is that the students are not asked "Can you understand what the academic says clearly?". They are merely asked to rate the academic using a number and are not required to give any reasoning. This hides any prejudices they have and allows the hiring/evaluation committee to use racial preferences without having explicitly to admit they are doing it. The committee just says "They got low student evaluation scores".
Recognize that you may or may not have an implicit bias, and examine your own actions accordingly. This also goes for sexism. For example, rather than simply assuming "I'm not a racist!", sit down with something like the list of invited speakers for a conference and genuinely ask "Did we include people of color? Did we include women? Were they more than tokens?"
Like all things in academia, reducing bias benefits from rigorous, systematic thought.
Do unto others as you would have them do unto you
I believe that this is really the only thing that is in your control.
As the popular song goes, "Everybody's a Little Racist". :D
You cannot change minds of people forcefully but you can only change the way in which you behave.
Having said this, I don't think that I have faced any instance of racism inside the ivory tower in the US. Socially, yes. Academically, no.