Erosion is the process of moving weathered material from one place to another. So, while weathering is the first step in the process, it's not what "starts" erosion. Erosion itself starts when something picks up the weathered material and moves it.

Here are some of the things that can start erosion:

* Water: Rain, rivers, ocean waves, and glaciers are powerful forces that can carry away soil, rocks, and other materials.

* Wind: Strong winds can pick up and transport sand, dust, and other loose particles.

* Gravity: The force of gravity can pull rocks and soil downhill, causing landslides and other forms of erosion.

* Ice: Freezing and thawing of water in cracks can break rocks apart, and glaciers can carve out valleys and transport large amounts of rock and sediment.

* Living Organisms: Plants, animals, and even humans can contribute to erosion. For example, plant roots can break up rock, and animals can trample the soil, making it more vulnerable to erosion.

So, the "start" of erosion is the force that begins moving the weathered material, not the weathering itself.