The climate chaos caused by the rapid rise in CO2 levels in the atmosphere is only one reason that we need to reduce carbon emissions, the other is that it is making the oceans more acidic.
The oceans naturally absorb around one third of our CO2 emissions every year, but while removing it from the atmosphere is a good thing from a climate standpoint, the effect on ocean chemistry could be just as catastrophic. CO2 dissolves in seawater and forms carbonic acid which lowers the PH. This reduced PH is already being seen by scientists. Many life forms at the base of the oceanic food web depend on carbonate shells or exoskeletons, and if the sea becomes too acidic they will no longer be able to make them. Studies of corals on the Great Barrier Reef have shown that growth rates are slower now than they have been in 400 years.
Over 150 marine scientists have signed the Monaco Declaration (pdf) expressing their alarm over findings of increased ocean acidification worldwide. Although CO2 levels have been higher in the past, the extreme rapidity of the current changes will leave no time for ecosystems to adapt. I recently read a study on the correlation between lack of coral reefs and mass extinctions, so even if you don't think our excess CO2 emissions are warming the earth there are other important reasons we need to reduce them.