Even if we stopped all emissions of CO2 right now, atmospheric levels would continue to rise for some time. CO2 stays in the atmosphere a good long time. The oceans that have absorbed about half of the CO2 we have emitted will become a source of CO2. We have set off feed back loops, particularly the melting of the Arctic tundra, that will continue to put more CO2 (and the much-more-powerful CH4) into the atmosphere...

Maybe CO2 emissions will continue to rise because of the various thermal equilibrium effects and radiative effects of CO2/CH4, etc. However, if you look at the CO2 it does suggest that it is possible to greatly reduce the rate of increase or essentially stop it if (and it's a mighty big if you drop back the rate of CO2 addition to the atmosphere to the levels of the late 1960's or early 1970's.

As I heard recently, and long ago concluded myself from the data, it's the cummulative effect that is difficult to deal with given the long residence time and turnover rates of the ocean and the atmosphere in this dynamic equilibrium we see everyday.

In May at Mauna Loa we hit the highest value for CO2 that has been observed at that site and in more than 800,000 years from EPICA data. Today's values are much higher than any previous interglacial we can find in the ice record. No matter what there is a lot of thermal inertia to contend with and that is something to be concerned with.