There is lots of stuff we don't know. Lots of stuff without firm scientific support. Yet in many areas without firm scientific support, we often encounter zealous advocates who either believe we know much more than we do or are confused as to what we actually know.
The Big Bang Theory doesn't explain what caused the universe to come into being.
How did the universe come into being? There is plenty of good observational evidence for the Big Bang theory. But that doesn't explain how the universe came into being in the first place. What happened before the big bang? Science is unable to describe the universe before the Planck Epoch (when the force of gravity separated from the elctronuclear force). Currently, we don't know what caused the big bang or how the universe came into being.
The Theory of Evolution doesn't explain how life originated.
How did life start? There is plenty of observation evidence for the theory of biological evolution. But that doesn't explain how life came into being in the first place. What happened before there were organisms? Science is unable to explain how organisms came into being in the first place. There is no scientific consensus on how life began. Currently we don't know how life began.
(FYI: Intelligent Design is one argument for how the universe and life began. It has about the same scientific support as any other argument for how the universe and life began. That is, none. Of course, Intelligent Design isn't exactly scientific. But then again science hasn't provided any answers yet either.)
The Theory of Global Warming is infected with politics for the time being.
In a few decades we might know whether the current scientific consensus and environmental hysteria comports with the data. To the extent there is a consensus, the science remains shaky--far shakier than what we know about the origins of the universe and of life. Far shakier than the consensus scientists would like you to believe. (I think many of them don't even understand why "consensus science" isn't actually science.)
We don't know how to reliably educate low-IQ/low-SES children
The science is very thin on improving student achievement outside of the elementary school years. Most theories aren't even based on actual testing of an intervention. Most theories are based on observations of correlational data on broad proxies for variables believed to affect education (poverty, teacher efficacy, availability of free lunch, availability of health insurance, and the like). not so much on actual interventions designed to improve or ameliorate these variables.
So what is government policy, like Race to the Top, based on?
Sunshine and lollipops mostly.