Answer: It's expensive! and more.
Explanation: The process of switching to renewable resources is very difficult for a wide number of reasons. When looking at the most obvious and important reason is the cost of replacing pre-existing technologies with new ones. If we were to all at once phase out every non-sustainable energy production, we would have to deal with disposing or recylcing the plants, resources, and bi-products. Additionally, replacing jobs, industries, and educations would impact employement and take a lot of time and money, and rebuilding our energy infrastructure is one of the biggest costs, resources, money. and time-wise, and would take the longest and be the most difficult part of the task of replacing with renewables. When looking at the total emissions cost of production and and and harvesting raw materials, you tend to put out more of a carbon footprint than you conserve. Although over time it would give you a net gain of neutralization of carbon emissions and natural resource use, it would take a long long time to get to that break-even. When you consider the number of cars on the road that uses fossil fuels, the amount of homes powered by nuclear and coal power plants, the number of recreational vehicles requiring gas, and the number of jobs involved in the production of all of this, you end up producing more carbon than you conserve.