The most rapidly depleting natural resource in the world is:

Natural resources are materials or substances that occur naturally in the environment and can be used for economic gain. These resources can be classified into two main categories: renewable and non-renewable.

Forests are the most rapidly depleting natural resource in the world due to human activity. Deforestation is occurring at an alarming rate, which is causing widespread environmental damage and loss of biodiversity.

Water is a precious resource, and while it is also under threat due to human activity, it is not being depleted as rapidly as forests. Wind and sunlight are renewable resources and are not being depleted at all.