Achieving 7% renewables by 2020 is not that ambitious. States like California and Colorado have 33% and 30% renewable mandates respectively by 2020, and they are on target to achieve those goals. In 2011 the US got about 5% of its electricity from renewables (
http://www.eia.gov/tools/faqs/faq.cfm?id=427&t=3 ); it's probably one or two percent higher now. Much electricity production in the US has shifted from coal to natural gas, which in the short to medium term results in a net reduction in CO2.
The point is that if having a national mandate is seen as the only way to achieve gains in renewables, then Abu Dhabi is not that great an example. It's not doing any better than the more fragmented and contentious US in its efforts. Perhaps the messy process of democracy isn't that much worse after all.
