New York City looks to lower greenhouse gas emissions by improving public housing

The city is piloting heat pumps instead of older boilers.

As cities across the country work to meet clean energy goals in the coming years, a critical focus is being placed on public and affordable housing.

There are more than 1.2 million public housing units across the country, according to the Department of Housing and Urban Development. Many of these buildings have aging heating and cooling equipment that is largely inefficient, resulting in expensive utility bills.

Low-income households spend three times more income on energy bills than those living above the poverty line, according to the American Council for an Energy Efficient Economy. Not only are these systems expensive, they also rely on fossil fuels, making them significant sources of greenhouse gases -- any gas that absorbs heat and radiates it back at the Earth, causing global warming.

In America's largest city, New York, more than 80% of low-income housing relies on old boilers fueled by natural gas, propane or oil. The New York City Housing Authority oversees more than 170,000 units and is the largest landlord in the city. The agency is looking to the future, and is required by law to reduce its greenhouse gas emissions 40% by 2030 and 80% by 2050. To tackle that goal, NYCHA is beginning to address a long-standing problem with energy in its buildings.