Let's go through a few online sources (per google search) and identify top issues
http://www.unialliance.ac.uk/campaigns/problemsolved/environmental-change/aviation-industry/
Issues identified: noise (though more about flight path - I'd think companies have less control), pollution (2.-3% of CO2 emissions per year of human activity)
--Philipp.....2016-12-13 16:15:54 UTC
Of course this is perhaps one of the most important steps. Its also about context and materiality.
--Philipp.....2016-12-13 16:21:09 UTC
This report points a way how to come up with suitable indicators. They state "The method for developing KPIs for sustainability relies on three principles-–simplicity, materiality, and transparency." I would add "context".
Issues identified (they use airline industry as an example - how convenient!): flight hours logged per pilot; accidents; average age of fleet; average days of worker strikes as example for metrics.
Top issues, after materiality assessment (page 29):
- climate change mgmt; competitive and ethical behaviour; customer privacy; customer satisfaction; energy; environmental mgmt; impacts on communities; labor rights and compensation; materials and waste; pollutants and emissions; product and operational efficiency; product environmental impact; product safety; sourcing practices; standards and codes of conduct.
--Philipp.....2016-12-13 16:23:29 UTC
Issues identified (related to airlines): engine noise and pollution (NOx; Co2; particular matter). Future: alternative fuels. Emissions trading.
--Philipp.....2016-12-13 16:31:47 UTC
That's already quite a few things to consider. I'll start with the ones that resonate the most with me personally for now, hoping to learn more in the process.