Los Angeles officials on Tuesday moved to declare the rising problem of homelessness an “emergency” in the city and proposed spending $100 million to provide permanent housing and shelters to help the city’s 26,000 indigent. Mayor Eric Garcetti joined several City Council members in unveiling the plan, which follows an increase in the city’s homeless population from just under 23,000 two years ago, according to the Los Angeles Homeless Services Authority. With a number of luxury residential buildings opening in recent years, especially downtown, some community groups blame gentrification for contributing to the city’s skyrocketing rents and worsening homeless problem.