Yes, many smaller businesses can become carbon neutral, depending on their current carbon footprint and the infrastructure/technology alternatives available to them. Many more will be able to do so as better infrastructure and technology becomes available. (The individuals referred to are all interviewed on my podcast.)
The first step is almost always to become more efficient. For example, it's amazing how many businesses are both heating and cooling the same space. Consider a commercial kitchen, which often becomes ferociously hot especially in the summer because conventional gas cooktops give off a lot of heat. Induction cooktops cook the food without cooking the cooks, and produce better indoor air quality which might support the health of the workers. In other spaces, old fashion lighting may give us a lot of heat, when LED lights can provide the same illumination without heat. On my podcast, Bruce Taylor's interview describes other examples where he's been able to save clients quite a bit of money by eliminating waste of energy, water and materials.
The second step is to eliminate or destroy high global warming potential gases that are leaking into the atmosphere, such as refrigerants, anesthetics, methane. These gases can do an enormous amount of climate damage, and can be captured or destroyed comparatively inexpensively. In many cases, the captured gases have an economic value, e.g. anaesthetics can be cleaned and reused; methane can be burned for energy (see Audrey Mascarenhas interview).
Third, figure out the business’ remaining direct carbon footprint, and reduce as practical. In Ontario, half of the average carbon footprint comes from just four things: driving, heating leaky buildings, flying (before Covid), and meat. Increasingly, there are good alternatives to each. Meat is the easiest part, because there are so many good meat substitutes available. Virtual technology makes it easier to dramatically reduce flying, though admittedly zoom is not the same as being there. For driving, electric vehicles increasingly have a lower total cost of ownership, especially for those who drive long distances, because of reduced maintenance, dramatic reduction in fuel cost, and the likelihood of increased durability because there are so few moving parts. EVs also tend to be more fun to drive. (And, as David Roberts explains, there are other business benefits from being a better neighbour; EVs are much quieter, don’t smell, therefore better neighbours than diesel buses, which is helping with their social license.) There are also lots of options for reducing fossil fuel use in buildings, including adding solar (Mike Andrade; Richard Sefton), and joining a district heating system where possible (see Catherine Thorn’s interview).
Fourth, look for opportunities to sell low carbon services or products. Carbon Cure in Halifax sells technology that strengthens concrete by displacing some of the expensive cement with captured CO2. This saves their customers money and sequester carbon at the same time. Woodland Biofuels expects to sell the world's cheapest liquid transportation fuel, by making it out of construction waste. Their plant isn't even built yet and the entire product output is already sold. Brandon Moffat is turning food waste into low-carbon fertilizer, electricity and natural gas.
Fifth step is to buy from greener suppliers. For example, Canada's big banks are huge fossil fuel funders, but equivalent banking services are available from Desjardins Financial, which has made serious low-carbon commitments, and is steadily delivering them. Most smaller businesses can choose a lower-carbon financial institution. Similarly, there are lower carbon alternatives available for a huge range of goods and services that smaller businesses buy, from steel to cheese to trucking to electricity.
The sixth step, for those who want to be carbon neutral now, is to offset their residual emissions. This can be done by buying good quality carbon offsets from a certified source. (Please note that I can rarely support some of the cheaper offsets, such as treeplanting.) Some businesses can directly restore a damaged ecosystem. For example, Bryan Gilvesy made his cattle ranch more profitable and resilient by replanting native tall grass prairie, which his heifers happily eat in August when conventional pastures wither in the heat. It also allowed him to eliminate pesticides because the prairie attracts birds which eat the bugs, plus the deep roots of the prairie plants also sequester a lot of carbon.
The seventh and even more important step is for small businesses to speak up, individually and through their associations, to demand that governments take strong action to create the infrastructure and technology to support a low carbon transition. The climate crisis is a collective problem and it cannot be solved by individual humans or by individual businesses. Individual action is an important place to start but a terrible place to stop.