1) Checking the air locked in icebergs shows CO2 level cycles.
They show that the high levels of CO2 in our atmosphere aren't the highest in history, and perhaps they are a result of a natural cycle and not just our air pollution.

2) No one managed to agree if the high CO2 levels came before Ice-period or after.

That means there are 2 valid propositions - one is that high co2 levels raise the temperature and thats what stopped the ice-age. In this case we are in trouble. The other means that high co2 levels can be something that happens naturally when earth is nearing an ice-age and it may be what is happening now.