From cake smeared around the “Mona Lisa” to soup splashed about “Sunflowers,” recent climate protests at art galleries have grabbed international headlines but also elevate issues about the efficiency of these significant-profile guerrilla methods.  Vermeer’s “Girl with a Pearl Earring” was the most current portray to fall target to artwork-based activism, which has seen environmental campaigners concentrate on well-known artworks, just about constantly with cheap foodstuff products, to attract attention to the use of fossil fuels.   Two men sporting “Just Halt Oil” T-shirts jumped the rope separating the priceless 1665 Dutch masterpiece from the community at the Mauritshuis museum in The Hague on Thursday. A video clip posted on…