Energy consumption is one of the main human activities driving global climate change, and therefore research on the carbon footprint of energy consumption is of great significance. In this paper, concepts and methods relating to the carbon footprint of energy consumption were used to calculate total carbon footprint, carbon footprint of each type of energy, output value of the carbon footprint and its ecological pressure from 1990 to 2009 in Gansu Province, northwestern China. The ridge regression function within the STIRPAT model was applied to study the quantitative relationship between carbon footprint and economic growth and at the same time verify the existence of an Environmental Kuznets Curve. A decoupling index was introduced to further explore the dynamic relationship between economic growth and carbon footprint. We found that the total carbon footprint increased from 0.091 ha per capita in 1990 to 0.191 ha per capita in 2009 and followed a fluctuating rising trend. Coal and oil occupy the dominant position within the carbon footprint composition, while natural gas is of little effect. The output value of the carbon footprint increased from 11 800 CNY per ha in 1990 to 25 100 CNY per ha in 2009, representing an average annual growth rate of 4.1%. The ecological pressure intensity of the carbon footprint increased to 0.24 in 2009, and remains much lower than developed provinces Jiangsu and Shanghai, due to the vast area of woodland in Gansu. Development of a low-carbon economy in Gansu remains hindered by limited energy, a fragile ecological environment and irrational energy structure. Population and GDP per capita growth were the main factors driving the increasing carbon footprint; the impact of population is 3.47 times of that of per capita GDP. Regression analysis and decoupling index analysis have proved the existence of the Environmental Kuznets Curve for economic growth and carbon footprint, but 33 years are required to reach the inflection point.