It will be a Christmas without cards but plenty of greetings in a green way. Friends of the Earth is hoping to reduce by 500,000 the number of Christmas cards sent this year, equivalent to 125 trees - about the number of cards being mailed out by companies in Hong Kong every year. Since the Green Christmas Campaign kicked off in 1995, the group has been urging a cut in the number of Christmas cards. Last year, with a total of 74 private firms and government bodies participating, about 300,000 fewer cards were printed, sparing about 75 trees from being axed.