Global Warming Hypothesis meets Falsifiability

Falsifiability: is the logical possibility that an assertion can be shown false by an observation or a physical experiment.
Some philosophers and scientists, most notably Karl Popper, have asserted that a hypothesis, proposition, or theory is scientific only if it is falsifiable.[source]

Is there an empirical falsification for anthropogenic global warming?
''I have recently challenged someone to come with such an empirical falsification for anthropogenic global warming.'' [source and details]

Falsifying the Global Warming Hypothesis By Michael R. Fox
''There has been no warming over the past 10 years and a slight cooling for the last 6 or 7 years. In the meantime the CO2 emissions have continued to increase. The hypothesis predicted warming over the last 10 years, while no warming and even cooling has been observed. The AGW hypothesis again is falsified.'' [source]

So: what do we/they really know for sure about the planet's climate? :D