On 10th January, New York Mayor Bill de Blasio announced a lawsuit against ExxonMobil, Shell, Chevron, BP and ConocoPhillips, as the top-five investor-owned companies "measured by their contributions to global warmings". The lawsuit seeks damages to cover costs incurred by the city to adapt to the effects of climate change. Wood Mackenzie's own analysis of the companies' upstream oil and gas emissions provides a more nuanced perspective. Though the five companies do represent some of the oil and gas industry's largest emitters in absolute terms, other companies with at least partial public shareholdings have larger or equivalent emissions footprints. Similarly, the companies rank comparably or better than other publicly owned oil and gas companies on the basis of emissions intensity, which is a more standardised metric to measure companies' emissions performance. Moreover, they are all starting to take steps to reduce the emissions intensities of their upstream portfolios.