I have started a personal project researching a few endangered species and the conservation work being done.
The pandas, for example, are living proof that conservation does work. As of now there are 1864 pandas that remain in the wild, compared to 1000 in the 70s, it's a success story of human conservation work. Arctic foxes, vultures, etc also have been saved by conservation.
However, a lot more works needs to be done to save the animals and ecosystem on the planet. The Great Barrier Reef, for example, is under great threat linked with rising water temperature; the turtle population, has a lot of do with plastic waste.
It takes global effort.