Background: Michael Bloomberg was born at St. Elizabeth's Hospital, in the Brighton neighborhood of Boston, on February 14, 1942. Bloomberg's family is Jewish. Bloomberg's father, William Henry Bloomberg (1906-1963), was born in Chelsea, Massachusetts and worked as an accountant for a dairy company. He was the son of Alexander "Elick" Bloomberg, an immigrant from Russia.
Context: During his second term as the mayor of New York City, Bloomberg unveiled PlaNYC: A Greener, Greater New York on April 22, 2007, to fight global warming, protect the environment and prepare for the projected 1 million additional people expected to be living in the city by the year 2030.  Under PlaNYC, in just 6 years New York City reduced citywide greenhouse gas emissions by 19% since 2005 and was on track to achieve a 30% reduction ahead of the PlaNYC 2030 goal. In October 2007 as part of PlaNYC, Bloomberg launched the Million Trees NYC initiative, which aimed to plant and care for one million trees throughout the city in the next decade. In November 2015, New York City planted its one millionth tree, two years ahead of the original 10-year schedule.  In 2008, Bloomberg convened the New York City Panel on Climate Change (NPCC), an effort to prepare the city for climate change. In 2012, Travel + Leisure readers voted New York City the "Dirtiest American City," for having the most extant litter. Bloomberg has been involved in motivating other cities to make changes and has spoken about reducing carbon dioxide emissions, using cleaner and more efficient fuels, using congestion pricing in New York City, and encouraging public transportation.  Bloomberg unveiled the Special Initiative for Rebuilding and Resiliency (SIRR) in June 2013, after the city was affected by Hurricane Sandy in October 2012. The $20-billion initiative laid out extensive plans to protect New York City against future the impacts of climate change. On September 26, 2013, Bloomberg announced that his administration's air pollution reduction efforts had resulted in the best air quality in New York City in more than 50 years. The majority of the air quality improvement was attributed to the phasing out of heavy polluting heating oils through New York's "Clean Heat" program. As a result of the improved air quality, the average life expectancy of New Yorkers had increased three years during Bloomberg's tenure, compared to 1.8 years in the rest of the country.
Question: What enviromental issues did michael help with?. Whats the answer?
to fight global warming, protect the environment