There are but they operate over really long time periods, tens to hundreds of thousands of years. The balance is naturally restored through an increase in weath

There are but they operate over really long time periods, tens to hundreds of thousands of years. The balance is naturally restored through an increase in weathering rates (which are a function of of the CO2 concentration in the atmosphere). The rate at which we are pumping carbon is unprecedented for at least the past 66 million years. There's no natural mechanism which could restore the balance fast enough. I have a PhD on this topic, I investigated climate change and climate evolution in deep geological times in order to find a proxy to what's happening today. The closest thing that ever happened in the past 66 million years is the PETM (see my other comments in this thread). I'll be glad to any questions that you might have.