Biogas: A threat or rescuer of the global environment?

Biogas is in principle a mixgure of methane and carbon dioxide. Nature is producing biogas since billions years ago. but today:

Scenario 1:
Biogas is a threat to the global environment. It is produced by landfills, rice fields, ponds, cattles etc., and has a great contribution to the global warming. One ton of methane has similar effect as 21 tons of CO2 on the global warming. So, biogas is obviously a threat!

Scenario 2:
Biogas can be produced in a very small reactors, e.g. 0.1 liters, until very large reactors such as 10,000 m3. It can be produced by the kitchen waste of a household or a big plant from e.g. organic wastes of a city. The methane is just the "natural gas" and can be easily separated from other gases by a simple water scrubbing. The methane can be used for heating, cooking, lightning, electricity production, or as car fuel, as it is already used in many countries in the world. We have today a network for tranportation of methane, knowledge to produce it and the technology to use it to run our cars or produce electricity. It can be produced all around the world in any sizes, and meet our demand of energy. So, the biogas is the rescuer of our environment!

The human society should decide about scenarion 1 or 2?