I'm sorry, but that is patently false. In addition to massive habitat change triggered by global warming that is wiping out countless species, we have a very well defined issue with acidification of large water habitats that are killing entire ecosystems, such as reefs.
Acidification that is a direct consequence of CO2 emissions.
And one last time. We are in fact emitting less CO2 than system absorbs. FAR less. The problem is that system itself also emits CO2 and is by design made in a way that adapts to exceptional events that emit large amounts of CO2 by absorbing even more. The problem however is that before CO2 is absorbed, it causes increased amount of thermal reflection back to the planet, which is what we call a greenhouse effect.
Normally CO2 emissions fluctuate with period, as ecosystems themselves work in different ways. Much of our current plant life for example would absolutely LOVE more CO2. Far more. That is why we have far more CO2 in greenhouses. It makes plants more efficient.