How do invasive species impact people on Earth?
Very badly, by reducing the biodiversity, affecting the cultures and native species, spreading disease, destroying environment...
A invasive specie is a non-native specie which the populations grows very fast and spacially spread because of the lack of biotic constraints (efficient predators/competitors/parasits/illness...). By spreading and growing, the invasive species threats the native species by having a perturbation, predation or competition activity.
An invasive specie reduce the biodiversity and is very dangerous to ecosystems.
The biodiversity importance
Every day we benefits from ecosystemics services (agriculture, water cleaning, air cleaning, fishing or hunting activities, eco-tourism...). The biodiversity is really important to the well-being of ecosystems because it's what allow them to resist and perform.
Effects on people
By threatening the biodiversity, and so the environments quality and so its benefits, the invasive species has a really bad effect on the people, which sees their natural ressources decrease.
New Caledonia's example
For example in New Caledonia, the deer is an invasive specie and by browsing, the vegetation in the mountains get scarcier, which leads to land slides and threatens the native fauna, flora and the agricultural activites.
May it help you !