I'm an engineer with experience in the area of sustainability & tech (working for a pharmaceutical company) and would like to further my studies. I see that there is at least some connection between MBA and this field, as many programs include it to some extent, but I wonder if it might be a path worth pursuing or I should be putting my focus elsewhere. Any experiences? I see Warwick, Exeter and MIT Sloan amongst the most highly regarded unis when it comes to this.

Sustainability makes a lot of sense. I think HEC has the right approach here. The Exeter programme seems to serve student interest rather than employer demand. See this old blog of mine: https://www.influencerrelations.com/1329/is-sustainable-business-selfish-or-altruistic 

There are two other programs that you can consider if you are open to part time options.

- MSt is Sustainable Leadership, University of Cambridge 

-MSc Sustainable Urban Development, University of Oxford