During the first three months of 2007, the topic of greenhouse gas emissions and their possible influence on climate change moved to the fore thanks to several events. The United Nations-sponsored International Panel on Climate Change reported in February that there is a 90% likelihood that human activity is influencing the warming of the planet. Former vice president Al Gore’s documentary on the topic earned an Academy Award, and the Democratic Party’s newfound control of both chambers of Congress has led to hearings on the issue before the relevant congressional committees.

The present "political climate" suggests that a more proactive federal program to curb greenhouse gas emissions may be implemented soon. Several states have already taken steps to do so. California announced a plan in mid-2006 to reduce emissions using a cap-and-trade system, and several neighboring states (Oregon, Washington, Arizona, and New Mexico) recently signed on to cooperate. In the Northeast, seven states (Connecticut, Delaware, Maine, New Hampshire, New Jersey, New York, and Vermont) formed the Regional Greenhouse Gas Initiative (RGGI), which is also a cap-and-trade system. Maryland is slated to join the RGGI in mid-2007, while four others (Massachusetts, Pennsylvania, Rhode Island, and the District of Columbia) are listed as “observers.”

The momentum of such policies leads us to take a closer look at greenhouse gas emissions across states. The tables below show the highest- and lowest-ranking states in terms of nonresidential carbon dioxide emissions (the most prevalent greenhouse gas) per job. The 2003 data are the most recent available.

Metric Tons of Carbon Dioxide Per Job – Highest in 2003
Alaska	73.1
Louisiana	47.9
Wyoming	40.5
Texas	26.9
North Dakota	21.4
West Virginia	18.4
Indiana	18.3
Oklahoma	13.0
Montana	12.4
Alabama	12.1

Source: Environmental Protection Agency and Global Insight

Metric Tons of Carbon Dioxide Per Job – Lowest in 2003
Massachusetts	2.1
New York	1.9
Florida	1.9
Nevada	1.8
Connecticut	1.8
Arizona	1.8
New Hampshire	1.7
Vermont	1.7
Rhode Island	1.2
District of Columbia	0.2

Source: Environmental Protection Agency and Global Insight

The most striking feature of the data is the variance across states. The figures above includes emissions by the commercial, industrial, transportation, and electricity-generating sectors. Generally, the states emitting the most carbon dioxide per job are those with a significant amount of mining or manufacturing activity, or also use relatively more coal in electricity generation.

Alaska produces the most amount of carbon dioxide per job by far, which is attributable to its petroleum and mining industries. The state's industrial sector accounts for nearly half of its carbon dioxide emissions, compared with a national average of 18%. Louisiana and Texas also have high emissions in the industrial sector because of extensive mining activity. Wyoming also has significant emissions from its industrial sector, and is also high on the list because 96% of the state’s electricity production comes from coal-fired plants.

The states at the bottom of the rankings have dramatically smaller emissions from industry, and also have less carbon-intensive electricity generation. Vermont produces most of its electrical power from nuclear generators, while Rhode Island’s electricity is generated nearly exclusively from natural gas. New Hampshire uses some coal, but more electricity comes from natural gas and nuclear power.

The above tables are not intended to point out the most egregious polluters, as the comparisons would be unfair. Alaska and Texas accounted for 16% and 20%, respectively, of U.S. crude oil production in 2005, which enables residents in all states to operate their automobiles. Typical cap-and-trade legislation allows for such dynamics by establishing greenhouse gas caps based on historical levels or percentage reductions in current levels. The tables only reveal the most carbon dioxide-intensive economies that may have a harder time coping with mitigation policies. Indeed, many of the states that have voluntarily entered these initiatives are found at the bottom of the rankings, and none are in the top 10.