Weathering is related to the breaking down and loosening of rock or soil into smaller pieces, but the weathered pieces remain in place. Erosion is related to the movement of weathered (and sometimes non-weathered) pieces away from the source.
The greenhouse gas raises the temperature by trapping the earth radiant heat inside the atmosphere and warming also increases the accumulation of the atmospheric water and most abundant in the greenhouse gases. And this accelerates the greenhouse effects.
