The difference may be obvious to some but to others I suspect it is not so obvious and the media isn’t helping much in their rush to cover all things green.
Just because something is renewable doesn’t make it sustainable. Case in point: biofuels (aren’t they just all the rage these days? ). Certainly we can get fuels from plants and we do. But currently in order to get ethanol requires the input of a lot of fossil fuel so that what we are getting out is about equal to what we are putting in and the net result is we really aren’t getting anything. The plants can be regrown so they’re renewable but given the needs of fossil fuel input to make the ethanol production system work it certainly isn’t a sustainable thing.
An even more obvious example was given on the latest Deconstructing Dinner podcast: whale oil.
At one point in time whale oil was the main source of fuel oil for lamps, etc. Certainly whales are a renewable resource. They die and more are born. Simple right? But as the fuel oil needs grew and grew more and more whales were being killed and some species were almost driven to extinction. Clearly that was not a sustainable practice.
We need to find a renewable source of energy that is also sustainable (wind power is a great example). Biofuels are not that source.