What have their social consequences been? Are these consequences solely due to these technologies, or have these technologies interacted with other sources of change? Topic 2
Technologies such as biofuel, solar energy, and hydrogen fuel cells have been developed and tested since the 1970s, yet they have not replaced or even come close to competing with fossil fuels. Is this another example of cultural lag? For more information about biofuels, see http://www.motherearthnews.com/green-transportation/vegetable-oil-fuel-veggie-van-zmaz99aszsto.aspx (Links to an external site.)