This is the first time I heard about silvopasture. Intergrating trees is pastureland will have multiple benefits if correctly managed, including crop diversification, better animal welfare from shade and windbreaks, improved forage quality(if managed properly) and carbon sequestration in soil. As with all solutions it will require careful planning to mitigate negative consequences from this change. 

Tidal and wave technology is at an extremely early stage of development and will require a lot of investment to become a significant portion of renewable energy. It is reliable, however, and would not add a carbon burden. The impact on marine life has not yet been adequately studied.