Fuel switching and state energy policies account for the majority of emissions reductions in the region. There are many other factors that have the potential to influence emissions, including population growth, weather fluctuations, the economic downturn and loss of manufacturing jobs.  However their relative impacts on emission trends have been minor.

The recent economic downturn has had some impact, but it is not the primary factor driving reductions

As shown above, the region has had continuous economic growth at the same time that emissions have decreased.

Population growth has been modest

Growing populations consume more energy and produce more emissions. In this region, population growth has been modest and is not a significant contributor to the recent emissions trends.

Weather changes have not been tied to emissions trends

Colder winters increase the need for heating energy, while hotter summers increase air conditioning use. There have been significant fluctuations in recent years, as well as a general warming trend, but the data indicate that these changes have had only a minor contribution to emissions reductions in the past decade.

The migration of manufacturing out of the region is a long-term trend

Emissions reductions in the industrial sector have been declining at the same rate as manufacturing jobs. This trend predates the economic downturn and has continued through it. While the shift away from manufacturing has led to in-region emissions reductions, in most cases the emissions are simply moving to the new location in another part of the country or world.