The small temple concept is a powerful one that may be leading us towards smaller, more sustainable communities.
-Less travel. Traveling great distances is not sustainable, cost-effective, or desirable. In the global context of the church, if the small temple concept continues to move forward, hundreds of thousands of families will be blessed every year with more time and money from reduced hours of travel and prices of fuel. Additionally, this helps decrease the carbon footprint of the collective church. I don't have any hard data, but since more than half the church resides outside of the United States, lets assume that prior to the small temple concept, most members lived a good distance from a temple. Even growing up in California, we were 3 hours from the nearest temple, or about 150 miles. If we assume 1 million members visit the temple twice a year, and have to travel an average of 300 miles round trip, this alone is a carbon footprint of 211,190.48, totalling $1,267,142.88 to offset the travel and become carbon neutral each year. On a churchwide global scale, these numbers can get staggering rather quickly.
-Can be built on any site. The last few years we have seen Temples spring up in suburban neighborhoods, the middle of downtowns of large cities, as adaptive reuse of existing buildings, as tenant improvements (one or two floors) in a larger development, etc. There is a lot of potential here, especially since this is simply a continuation of the first temple endowments which were given on the second floor of a red brick store in Nauvoo, Illinois.
-Limited hours open. Using the small temple concept allows for efficient and flexible use of resources depending on the area served. Most are open only by appointment which means it shuts down when not in use; lights go out, heaters and A/C are turned off. The savings from the utility bills alone makes this concept worth it. Having appointments also consolidates people into fewer sessions, and ensures that each session is full of people. When I lived in the Bay Area, it didn't feel right to go into a session in the Oakland Temple as one of only a few people in an enormous room.
With the church spreading all over the earth, it is possible that the days of the large, imposing temples such as Salt Lake, Washington DC, or Oakland are gone. The situation in Oakland is that it appears to be far too large for normal everyday use. With temples now in Sacramento and Fresno, Oakland primarily serves only the Bay area now. Granted, there is nothing as impressive as the Oakland temple and its site overlooking the Bay Area. It is one of my favorite temples. But the small temple concept would work nicely even in the heavily populated Bay area with potentially one in San Jose, one in San Francisco, and one in Walnut Creek.
Whether or not the above reasons were intended, the small temple concept provides lasting positive consequences that will bless the church and the environment for years to come. Let's hope that this form of bringing the temples to the people will continue and that it will be successful.