text: Yes they are, because all these are phenomena in which energy is transferred between different sources. Our planet receives energy from the Sun (as differente types of waves, including ultraviolet, visible and infrared=heat), and emits radiation back to space. In addition, there's a hot metal core that also releases energy. \nThe movement of masses of air (winds systems), water (oceanic currents), very hot solids (volcanic activity) are the mechanisms to reestablish the energy balance, because they basically distribute energy from high-energy spots to lower-energy spots. \nWhen one of these phenomena is disrupted, others become unbalanced and unpredictable effects follow.\n\nThe issue whether global changes are caused by man or not is a different issue; the answer to your question is Yes.