I am usually not a big fan of non-liturgical, secularly themed Sunday Church Services. In my opinion they often devolve into either what I call "liturigical tourism" or else a secular politic rant guised in worship form. By liturgical tourism, I mean turning the liturgy into a theological sight seeing tour that takes the emphasis away from proper worship of God and the proclamation and message of Jesus Christ and focusing on something else. While the "something else" might, in fact, be a legitimate cause or social concern, a priest has to make certain that the "something else" does not become the central, overarching focus of the liturgy. You can raise social awareness of issues or concerns without taking the focus off of God and the message of Good News.
I feel this way because it is a very slippery slope from having, for example, a "social justice" theme Sunday. That, in itself, is not necessarily a bad thing. Jesus called people to hear things and do things that were outside the mainstream understanding of community or politics of his time. But in my experience, particularly in seminary, when preachers start drumming the "social justice" liturgical war drum, it descends very, very quickly into synchronizing the preacher's own personal hobby horse politics (of whatever political stripe) with the message of salvation and Jesus. In my mind, that is a highly unethical use of one's pulpit. Jesus was not a registered political party member. Or as my mentor always said, "Salvation cometh not from politicians..."
As such, April 22nd is Earth Day, which is a Thursday this year. It is a trend in some churches and denominations to have an Earth Day Sunday, either before or after the actual date of Earth Day. Like I said before, that in itself is not necessarily a bad thing. Certainly, I believe Christians are called to be good stewards of what God has given us, not just in things like money but in natural resources, etc. I think there can be serious theology that can be worked into the proclamation of the Gospel on Sunday with those themes of whom and what we are called to be and do as followers of Christ.
Unfortunately, a lot of the Earth Day Sunday liturgical resources that are available to clergy planning Sunday worship are mostly on the bizarre and theologically dubious side. For example, I was going to try to incorporate some Prayers of the People apart from the usual 6 forms found in the Book of Common Prayer, but was largely horrified at the theologically vacuous Earth Day Sunday prayers available on line. Proper Sunday prayers should not descend into Paganism by praying to Mother Earth or Brother Sun or whatever.
The questions we should always ask is: Is some theme (like Earth Day) an icon we liturgically use to point people to God and the message of salvation, or are we oogling the theme like tourists taking pictures of the Grand Canyon?
Or, worst of all, is the theme (like Earth Day) what a visitor thinks we are worshiping?