James Hansen, and his team at NASA, predicted significant global warming (the green curve - Scenario 'A') if human CO2 emissions continued their existing growth path. They have.
The actual warming evidence though, does not comport with NASA's climate models. Per both the GISS and HadCRUT temperature datasets, global warming (black and red curves) are at, or below, the predicted values if CO2 emissions growth had been eliminated (the aqua curve - Scenario 'C'). That has not happened, based on the evidence through July, 2011.
Other failed-prediction postings.