Basically, fundamentally, the first thing to do is to increase the forest area where possible. Canada, unlike many other countries, does not have a significant problem of deforestation—in other words, the conversion of forest to other land uses—but we certainly do have opportunities for afforestation, whereby we take lands that are of marginal agricultural value or have been degraded from forest fires or some other causes and bring them back to act actively as carbon sinks. There are certainly many opportunities to manage our forests better to reduce the losses due to mortality, to go in and thin periodically, remove trees and basically manage forests so they are stronger carbon sinks.
The goal is to remove as much carbon dioxide from the atmosphere as possible. That being said, these forests cannot remove carbon dioxide indefinitely. They will grow older and bigger and become susceptible to insects, etc., so they are removing that carbon from the forest, allowing the next cycle to start again, and then making use of the carbon to the greatest extent possible.
To put it in perspective, we're removing about 180 million tonnes of CO2 equivalent of carbon in wood through the annual harvest. Roughly one quarter of the emissions from all other sectors is the CO2 that is in the wood that we remove from the forest, which was previously removed from the atmosphere. How we use that wood is critically important, and this is where we come back to the discussions we had previously about mass timber buildings and other ways of retaining that carbon in harvested wood products for the longest extent possible and while using these products to substitute for other products like steel, concrete, plastics, etc., that are very emissions-intensive themselves. If we could avoid producing steel or concrete to the extent that is possible and replaceable through wooden buildings, we could store the carbon from the forests in the building and avoid the emissions from steel and concrete.
The last point is that as we do all this, there will be residues and waste products at every stage in the process, from the slash piles that we discussed earlier to the bark and other material that is produced in various production facilities to construction waste and post-consumer waste. All of that material, if it can't be recycled or reused otherwise, can be converted into bioenergy, and in particular there are opportunities for second-generation liquid transportation fuels to help offset the very large emissions in the transportation sector using woody biomass as the raw materials.
This is in very broad strokes an outline of how this could be done, and of course I did not discuss potential implications for biodiversity, the impacts of climate change and some of the other complications.