NEW YORK (AP) — New York City Mayor Bill de Blasio plans to introduce a bill banning new construction of glass skyscrapers as part of his efforts to reduce citywide greenhouse emissions by 30%.

In announcing his Green New Deal on Monday, the democratic mayor said all-glass facade skyscrapers are "incredibly inefficient" because so much energy escapes through the glass. He said buildings are the No. 1 cause of greenhouse emissions in New York.

De Blasio says the bill would require existing glass buildings to be retrofitted to meet new stricter carbon-emissions guidelines.

"If a company wants to build a big skyscraper they can use a lot of glass if they do all the other things needed to reduce the emissions," de Blasio said. "But putting up monuments to themselves that harmed our earth and threatened our future that will no longer be allowed in New York City."

The mayor's Green New Deal effort also includes plans to power all of the city's operations with clean electricity sources like Canadian hydropower, mandatory organics recycling, congestion pricing, and the phasing-out of city purchases of single-use plastic food ware and processed meat.