TORONTO — Last week, the University of Toronto announced that most university-funded air travel will be subject to a carbon-offset fee based on the distance travelled. …But offsets won’t help green the university. …There is ample evidence that many carbon offsets – particularly those not regulated by governments – are of dubious quality. …The vast majority of carbon offsets also only remove greenhouse gases from the atmosphere temporarily – as long as the trees planted remain standing. Some of these “nature-based” offsets are increasingly at risk of becoming sources of greenhouse gas emissions, rather than sinks, owing to the growing threats of drought, fires and pathogens. By contrast, offsets that remove emissions and/or sequester it for centuries or millennia, make up only 3 per cent of the unregulated offset market. These permanent removals come much closer to a real solution. [the access the full story a Globe and Mail subscription is required]