Mississippi was found to be the least green state in America, with an overall index score of 33.7 out of 100. Across the various factors analyzed, Mississippi ranked last in transportation, scoring 15.3 out of 100. This score is due to 0% of vehicles in the state being hybrid or electric, the lowest in America. The state also has the third lowest percentage of its population using public transportation, at just 0.23%. 

Mississippi also has the lowest water efficiency and sustainability score, scoring just 2 out of 100 for this factor. In 2021, it was recorded that 2.59 million Mississippi residents had been served by water facilities that were contaminated or deemed unsafe to drink, the highest number in the country.  Mississippi’s population at the last census was almost 3 million.

2. Louisiana – Index score: 34.6 out of 100 

Second on the list is Louisiana, with an overall index score of 34.6 out of 100. Louisiana has the worst nature score in America, scoring 20.7 out of 100. Only 50 square miles of the state is covered by state and national parks, the fourth lowest amount in the country. Additionally, Louisiana has the lowest number of hiking trails, with just 125 across the state.  

The state also had an emissions score of 47.5 out of 100, due to the high volume of emissions produced. Annually, 183.3 million tons of CO2 is produced by the state, the sixth highest nationally. Additionally, Louisiana has the fifth lowest water quality score, at 14.6 out of 100.  

3. New Mexico – Index score: 35.2 out of 100 

New Mexico ranks as the third least environmentally friendly state, with an overall index score of 35.2 out of 100. This score comes in part due to the state having the fourth lowest water quality score, scoring 12.3 out of 100. This is a result of a high proportion of the state’s population being served by unsafe or contaminated water facilities, approximately 1.1 million residents. 

New Mexico has the 13th lowest air quality in America, scoring 39.8 out of 100 for this factor. The state also produces some of the highest quantity of fossil fuel emissions in the country. Around 9,265 thousand short tons of coal is produced annually in the state. 

4. Alabama – Index score: 35.8 out of 100 

Fourth on the list is Alabama, with an index score of 35.8 out of 100. Alabama has the second–lowest transportation score, scoring 15.9 out of 100. This is due to only 1.53% of vehicles being electric or hybrid and only 0.56% of the Alabama population commuting via public transport.  

Alabama has the fifth lowest nature score at 32.8 out of 100. Only 75 square miles of the state are covered by state or national parks, which is the sixth lowest size in the US. The state ranks 13th for the highest amount of CO2 being produced annually, at 98.3 million tons.  

 5. North Dakota – Index score: 36.3 out of 100 

North Dakota is fifth on the list, with an overall index score of 36.3 out of 100. The state has the third highest emissions rate, with around 3.32kg of black carbon emissions being produced per person annually.  

The state has the sixth–lowest transportation score, scoring 29.6 out of 100. This is due to only 0.19% of vehicles being electric or hybrid, the second lowest in the country. As little as 0.89% of North Dakota’s population commutes via public transport, the seventh lowest in America. North Dakota also scores very highly regarding fossil fuel production, with the second–highest rate in the country. 

6. West Virginia – Index score: 37.5 out of 100 

Coming in sixth place is West Virginia, with an index score of 37.5 out of 100. West Virginia has the country’s third lowest water quality score of 8 out of 100, which comes as a result of 934,993 residents being served by unsafe water facilities. It has an overall water efficiency and sustainability score of 11 out of 100.  

West Virginia has the 10th highest emissions rate in the country, with 76.9 million tons of CO2 emissions being emitted per year. Per person, around 3.08 tons are produced annually.  

Oklahoma is seventh on the list, with an overall index score of 38.8 out of 100. Oklahoma has the third–lowest transportation score, scoring 24.3 out of 100. Just 2.42% of the vehicles are electric or hybrid, and 0.18% of the state’s population commute via public transport.  

Oklahoma has the fourth lowest nature score, scoring 28.7 out of 100. There are 88 square miles of state or national parks and 389 hiking trails in the state, the fifth lowest in the country. The state produces approximately 63.1 million tons of CO2 emissions annually, which equates to approximately 5.92 tons of CO2 emissions per person.  

8. Alaska – Index score: 39.6 out of 100 

Alaska is eighth on the list, with an overall index score of 39.6 out of 100. When broken down, Alaska has the second–highest emissions score. The state produces 36 million tons of CO2 annually, and 2.59 tons of CO2 is produced per person annually. 

 The state produces the fifth-highest quantity of fossil fuels in the country, generating 1,042 short tons of coal per year. Alaska also has the 14th lowest rate of electric and hybrid vehicle usage, with 3.48% of all vehicles being electric or hybrid.  

 9. Texas – Index score: 40.7 out of 100 

Coming in ninth place is Texas, with an overall index score of 40.7 out of 100. Texas ranks eight highest in the fossil fuel category, with 17,250 thousand short tons of coal generated annually.  

Texas has the highest level of CO2 emissions in the country, emitting 624 million tons of CO2 annually, or around 5.93 tons of CO2 generated per person each year. The state has the eighth lowest air quality, scoring 37 out of 100 for this factor. 

Kentucky is 10th on the list of least green states, with an index score of 41.6 out of 100. Kentucky has the country’s 11th lowest water quality score, with a water efficiency and sustainability score of 28.50 out of 100.   

The state has the ninth–lowest transportation score in the US. When it comes to electric and hybrid vehicles, 2.78% are electric or hybrid, and 2.41% of the population in Kentucky commute via public transport. Regarding emissions, 101.9 million tons of CO2 are produced per year, and 5.61 tons of CO2 is produced per person annually.