The worldwide travel restrictions and numerous lockdowns instituted to combat the spread of COVID-19 have massively reduced greenhouse gas emissions, contributing to cleaner skies — even in some of the most polluted cities on Earth. The planet seems to be getting a much needed break amid a worrying climate change trend. Oceans are hotter than ever, the average global temperature has never been higher, and heatwaves are triggering unprecedented numbers of wildfires in regions such as the Arctic Circle, which includes Alaska.

While many countries have made aggressive commitments to reduce emissions, the United States, which is the world’s second largest greenhouse gas emitter, is falling behind. The U.S. is now one of only three countries in the world not participating in the Paris Climate Accord, an international landmark deal aiming to keep the increase in global average temperature to below 2°C, or 3.6 degrees Fahrenheit, above pre-industrial levels.

Some states, however, have taken steps to address climate change and protect the environment compared to the country as a whole. 24/7 Tempo created an index of air pollution levels, state energy generation and efficiency policy, and employment in green jobs to identify the 20 most eco-friendly states.

Environmentally-friendly states enact more aggressive local restrictions on energy use for their businesses and transportation systems; they use more renewable energy sources and less fossil fuels; and they generally have less pollution. Some 23 states and the District of Columbia have set their own greenhouse gas targets to reduce emissions in line with the Paris Agreement.

The burning of fossil fuels is one of the primary contributors to not just of greenhouse gas emissions, but also other forms of air pollution and environmental harm. While some U.S. states generate over 90% of electricity by burning coal, oil, or natural gas, other states’ electricity generation is mostly from renewable sources.

PM2.5 is shorthand for particulate matter that is 2.5 micrometers in diameter or smaller and that can be inhaled by humans and animals. These fine particles are produced by the burning of fuel in car engines, factories, domestic heating or by chemical reactions that take place in the atmosphere. The 24-hour concentration of PM2.5, the most harmful type of air pollution, is considered unhealthy when it rises above 35.4 μg/m3, but the annual average should not come out to more than 12 μg/m3.

Click here to read about the most eco-friendly states in America.
Click here to read about our methodology.