Make A Table Ignore Trivial Updates

The scenario: I own an ETL process. That process involves ingesting data from disparate sources and making my database sync with the latest. Let's say that I have a table called [catalog]. It contains my company's catalog of products. The source of truth for this table sends me a CSV every four hours. I ingest that CSV and make sure my [catalog] table is sync'd with it. I use an update like this:

UPDATE mc 
SET
	  [field1] = tc.[field1]
	, [field2] = tc.[field2]
FROM [my].[catalog] as mc  
INNER JOIN [their].[catalog] as tc
	ON mc.id = tc.id
WHERE mc.[field1]  tc.[field1]
OR mc.[field2]  tc.[field2]

This command will compare every match and filter out only those who will see meaningful change and updates those rows only. I don't want to touch any rows unnecessarily--the perennial task of ETL developers. No trivial updates will be executed (by trivial update, I mean an update to a row that changes *none* of the fields in that row). The rows without changes remain as they were, unmolested. Unmolested is a good word to use here because updating a row while not impacting values comes at an unnecessary cost. In ram and at the disk, an update to a row physically deletes the row with the old values and inserts a new row with the new values. All of these updates have to be logged! So, in the process of doing nothing, we have fragmented and split the index and data pages that we have for the table in both ram and on disk. And we're putting unnecessary traffic through the log. If we're not changing anything, then a trivial update is still causing churn in ram and on disk. Giving a table an *automatic* way to ignore trivial updates would be a big win for many scenarios. Now, let's just say that some ham-fisted developer makes an update through some client or in a procedure change that does something similar to a large table but doesn't include any measures to ignore rows not 'really' needing the update. Is there something that I can do to the table to make it act as if it knows to pass on trivial updates?