I suppose the real reason we're not tackling it full on is that it won't be a few percentage points.
Let's face it, the cost of abruptly stopping fossil fuel dependence would be high. Countries going bankrupt, people dying due to high fuel costs, enormous investments diverting money from other necessities.
It may well be necessary, and better than the alternative! But we tried the "just cycle a little bit more" approach and it made next to no dent to CO2 emissions. To really tackle it, we'd need to reinvent the global economy.