In the IRRI survey 2017, Leskinen was the world's TOP 50 ESG influencer in the asset managers category. In 2023 he was selected as the 29th most important ESG influencer in the world in the Onalytica listing.

Leskinen is an active speaker in domestic and international sustainable investing events. He has been on the Commission for Sustainable Investment of the Church Pension Fund (Kirkon eläkerahasto) from 2016-2020 and Chairman of the Finsif Board 2018. Leskinen has been widely quoted and also quoted in media and non-fiction books.