You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
New_York_City

Context:
The city government was a petitioner in the landmark Massachusetts v. Environmental Protection Agency Supreme Court case forcing the EPA to regulate greenhouse gases as pollutants. The city is also a leader in the construction of energy-efficient green office buildings, including the Hearst Tower among others. Mayor Bill de Blasio has committed to an 80% reduction in greenhouse gas emissions between 2014 and 2050 to reduce the city's contributions to climate change, beginning with a comprehensive "Green Buildings" plan.

Question:
What percent reduction of greenhouse gases does Mayor de Blasio want to see by 2050?

80%