As of 2nd quarter 2019 [1] rougly:

32% Energy, water and waste services

24.5% Agriculture, mining, industry, construction

12% Other services

13.5% Transport

18% Households

This is a major challenge (not only in the Netherlands) because it appears there is no one "bulk emitter" that must be tackled.

[1] https://www.cbs.nl/nl-nl/nieuws/2019/39/uitstoot-co2-hoger-i...