The start of 2022 marks a point of transition between Bill de Blasio’s eight years in charge of New York City and the arrival of Mayor Eric Adams. A mostly new City Council just took office.

THE CITY is giving New York City a checkup by tracking its vital signs year by year on health, poverty, crime, housing, environment, homelessness, transportation and education, showing progress through de Blasio’s terms in office into the pandemic — and the stage set for Adams.

The COVID pandemic prompted the biggest yearly drop in planet-warming greenhouse gas emissions thanks to a 21% decline in transportation emissions. 

In 2020, the citywide greenhouse gas emission inventory was 48.4 million metric tons, down 12% from the year before and 25% from 2005 — the year former Mayor Michael Bloomberg set a goal of reducing greenhouse gas emissions 30% by 2030 compared to 2005 levels and started to keep track of the inventory.

In 2014, ex-Mayor Bill de Blasio raised the target to 80% by 2050.

The city’s greenhouse gas emissions had by then fallen 15.3% from their 2005 level. Since then, it’s stayed much the same.

In 2019, the city’s greenhouse gas emissions were at 55.1 million metric tons — up 0.5% from 2013.

Ben Furnas, the final director of the Mayor’s Office of Climate and Sustainability under de Blasio, said 2019 was the “last baseline normal” year before the pandemic disrupted transportation and work trends — and called 2020 “anomalous.”

“I think it’ll always be an asterisk as we look at the long term trajectory of emissions in the five boroughs,” Furnas said. “Even with dramatically transformed patterns of economic activity, it’s striking that reductions weren’t even deeper, which speaks to the magnitude of the challenge ahead.”

The main greenhouse gas emitters include energy sources used in residential and commercial buildings as well as manufacturing, cars, heavy-duty trucks, landfills and waste management treatment.

To combat the changing climate and rising temperatures, on Dec. 15, the New York City Council banned the use of gas in new buildings. But greening the power grid is the major hurdle when it comes to reducing emissions. 

The city is banking on achieving the long-term emissions reduction goal in large part thanks to the development of offshore wind power, as well as new transmission lines that will bring renewable-source electricity from upstate and Canada into the city. 

PM 2.5, or fine particulate matter, is an air pollutant that can cause serious health problems.

In 2014, the concentration of PM 2.5 in New York City’s air declined below the federal threshold for harmful levels, after dropping considerably. An annual concentration level above 12 micrograms per cubic meter is considered harmful by the federal Environmental Protection Agency. 

The air continued to get cleaner from there.

One reason: a ban on dirty heating oil and other regulations, according to the city Department of Health and Mental Hygiene, which also found a 97% decline in sulfur dioxide emissions since 2009.

The pollutant comes from all kinds of sources: automobiles, burning wood, power plants, building boilers and space heaters.

The fine size of PM 2.5 — particles 2.5 micrometers or smaller — makes it dangerous compared to other particulate matter, as it can travel to the lungs and get into the bloodstream, leading to respiratory and heart diseases.

Read our coverage on climate resiliency.