The study, produced for the California Catholic Conference by Joseph Claude Harris, a Seattle researcher, paints a picture of a dramatically changing, growing Catholic Church in the state. The California Catholic Conference released results of the study June 19, 2006.

In 20 years, the study notes, Catholics will make up 36 percent of the state's population, up from 30 percent in 2005.

In 2005, 11.1 million of California's 36.6 million people were Catholic; by 2025, 16.7 million of state's expected 45.9 million residents will be Catholic, an increase of 5.6 million people. The Catholic population is projected to grow at a rate more than three times the 4 percent rate increase by California's non-Catholic population.

Catholics will represent nearly 60 percent of California's projected population growth in the next 20 years, according to the study.

"We are truly blessed that the Catholic Church in California is vibrant and growing, but our future should not happen by accident." said Bishop Stephen Blaire of Stockton, Calif., president of the California Catholic Conference.

"As pastors responsible for the spiritual well-being of our Catholic people, studies like this will help us do what we need to do to better serve the needs of burgeoning Catholic communities throughout the state."

By 2025, 4.3 million new Catholics will be baptized, more than 3.1 million children will celebrate their first Communion and the average parish will have expanded by more than 1,800 families. Of the state's projected total Catholic population increase of 5.6 million, 3.5 million is expected from the natural increase of number of births over deaths and 2.1 million as a result of migration from other states and countries.

A major factor driving the growth of the church in California is the growth in California's Hispanic population, an estimated 60 percent of who is Catholic.

The California Catholic Conference is the public advocacy office of the bishops of the archdioceses of Los Angeles and San Francisco and the dioceses of Fresno, Monterey, Oakland, Orange, Sacramento, San Bernardino, San Diego, San Jose, Santa Rosa and Stockton.