The government as well as private nonprofit groups offer help to people who are having difficulty paying their heating bills, especially as heating oil prices rise this winter.

Oil prices are expected to reach record levels this winter, but many users are unable to switch to natural gas or electricity, whose prices are going in the opposite direction.

As of April, new New York City heating oil regulations require that by 2015 the buildings switch from No. 6 oil, the cheapest and dirtiest fuel available, to No. 4.

Ground-source heat-pump geothermal systems take advantage of the earth’s constant temperature below the frost line to heat and cool buildings.

Under a lease with a sustainability clause, tenants can divide the savings from energy efficiency with the landlord, and those savings in turn can be used to pay for heating or cooling upgrades.

Proposed regulations would phase out the most polluting oils, No. 6 and No. 4, yielding health and environmental benefits.

By opening a new energy-efficient power plant that generates fewer conventional pollutants, New York University’s system will also emit 23 percent less carbon dioxide.

Kristianstad and the surrounding county essentially no longer use oil, gas or coal to heat homes and businesses.

Over the course of the last decade, Kristianstad’s government has orchestrated a conversion from mostly oil heating to green fuels like biomass, food processing waste and wood pellets.

After coal-fired heating kicks in, the United States Embassy describes high levels of air pollution in Beijing.