The problem with any assessment of environmental impact is the difficulty in judging the overalll effect. For example, a simplistic view would be that a new LP has used up some plastic, probably a derivative of a fossil fuel - oil. Conversely, a download might appear to waste nothing.
However, most downloads need a computer or similar device, decidedly short-lived, full of plastics and rare metals, and heading for a landfill within a few years. Many record players last decades (how many 20 year old pcs are on eBay compared with similar age record players?)
Compared to truly wasteful events like flying to another continent, the impact of just a couple of longhaul flights would probably be greater than everyone on this forum buying new records for the rest of their life!