To make matters worse, the most serious offenders are wood-burning heaters which are old or no longer functioning well, with open fireplaces among the most grievous.
The data led the Flemish government in October to sign up for the so-called Green Deal, which commits the government and a number of environmental and technology federation to cut back on the emissions from open hearths and wood- and coal-fired heaters by half by 2030, replacing them instead with more environmentally-friendly alternatives.
In his speech to the nation, meanwhile, the king spoke of the important themes of “inequality, poverty, intolerance and climate change” as “social problems that require global answers”.
The response on Twitter spoke of the monarch speaking from “one of his palaces” full of “glitter and gold” calling for an end to “inequality and poverty”. While another called for “next year scrap the crackling wood fire” with the hashtag #LeadByExample.