https://christopherkrapu.com/blog/2024/why-dont-we-just-free...

  In a previous section, I provided a rough number of 6800 kg. biomass harvested per hectare each year. To entirely offset global emissions of carbon dioxide, we would need approximately 40 billion tons sequestered per year; at 6 metric tons per acre, this implies 6 billion hectares of arable land. Unfortunately, we only have 1.4 billion hectares.

  I assume that the hemisphere is of sufficient size to accommodate the harvest of one township (approx. 9300 hectares)

Here, in one shire of a grain growing region, the central township area is 18 square kilometres (1,800 hectares) while the townsite and surrounding shire district area is ~2,100 square kilometres (210,000 hectares)(~800 sq mi) with an average single farm size of ~ 4,500 hectares (One local farm family I know of own that much land about their house, that much land again elsewhere, and farm much more land than that total they own via leasing and share farming - the 9,300 hectares quoted is more or less mean farming family harvest)

Not much scope here for bulk freezing biomass in winter though, there's rarely ice overnight and never snow here historically.

Still, details aside the roll your own biomass permafrost is an interesting take.