Loss of part of the earth's cryosphere will exert a positive radiative forcing effect on climate change because

The loss of part of the Earth's cryosphere can have a positive effect on the climate on a global scale. This will be due to the rise of the sea level around the world. The more the see rises, the more precipitation there will be, the more precipitation there is, the less the temperature variations and temperature extremes. Also, the water heats slower than the land and cools off slower than the land, thus it'll cause much more stable air temperatures across the world.