Re: "Canadian farmers fight climate change," (The Hill Times, by CSG Senator Rob Black, March 21, 2022). The media are full of reports of damage resulting from the deepening climate crisis, but there is little innovative to address the issue of food security. In The Hill Times, Black discussed the challenges of conventional agriculture under climate change, and the potential benefits of vertical farms. Then-Senator Diane Griffin had previously addressed the issue in The Hill Times in March 2021 in a piece titled "The path to food security in Canada" in the context of the COVID pandemic. The issue is clearly not getting the attention it deserves. A recent news article explored the idea of converting office towers for residential use. There are advantages and problems associated with this. The space may not partition well, windows may be far from inner spaces, and expensive modifications are needed to provide services. Changes may make it difficult to restore the building to its original use. Parking for residents might be inadequate. Given the impact climate change is having on countries closer to the tropics, it may prove prohibitively expensive or even impossible to import food from other countries, particularly in our winter season. To have a reasonable level of food security, it would be wise to plan and to experiment with ways to meet our own fresh-food requirements, and be ready to handle disruptions in the global food system. It is quite different to convert an office tower to a vertical farm. Plumbing, electrical and lighting systems need not be "built in." Therefore, it would be much cheaper to install, to maintain and faster to upgrade. Existing facilities—elevators and washrooms—near the service shafts would support workers without modification. Plumbing connections could be integrated into the benches for farmed crops with little change needed to connect to building systems. The whole system would be automated. Crops would be produced in the region of highest population density: downtown, limiting the transportation required and reducing the release of greenhouse gases and fuel consumption. In a closed system—like an office tower—energy and water requirements are reduced and the use fossil fuels eliminated. This needs a careful analysis. Tom McElroy Toronto, Ont.