In times of continuing fossil fuel combustion, anthropogenic challenges resting on phenotypic plasticity also become relevant. CO2 accumulates in the atmosphere and imbalances global carbon fluxes. We have recently described that like oceans also freshwater systems are prone to increasing levels of pCO2. During pCO2 peak periods, we showed that this affects Daphnia's ability to phenotypically adapt to an increased predation risk, reducing their ability to adequately form defensive features. We furthermore elucidated that it is not the decreased level in pH (which is a result of pCO2 increase) but an effect solely dependent on pCO2 increase. This in fact, we suspect to have cascading effects for the whole ecosystem. We now also studying the impact of increased pCO2 on the predator.