This paper uses DEA-based and non-DEA-based environmental performance measurement methods to develop and evaluate gas-flaring-related carbon emission performance indexes for dominant companies in the Nigerian upstream sector. The study relies on empirical data collected from the Nigerian National Petroleum Corporation’s Annual Statistical Bulletins. Indexes developed from the two methods are compared using paired two-sample t-test for means. Results documented reveal that most companies in the sector perform poorly and that, overall, the sector’s carbon performance indexes generated from both methods are poor. Moreover, performance indexes developed using the two methods are significantly different in terms of size, with DEA-based metrics being significantly greater than the non-DEA metrics. Further examination of the empirical results shows that reluctance by companies in the sector to embark on significant gas utilisations is further enhanced by the exploitable and vulnerable nature of Nigeria as a less developed country.
Keywords: gas flaring, carbon performance, carbon emission, index, data envelopment analysis, DEA, associated natural gas, upstream petroleum sector, Nigeria