Unwise development is also a problem in the tundra. Although human populations in the tundra are still low, development can have a drastic effect on the environment. Buildings and roads put heat and pressure on the permafrost, causing it to melt. Not only do the buildings sag and the roads buckle, but the fragile tundra soil composition is now ruined. People have developed refrigerated foundations to prevent the permafrost from melting and, therefore, buildings from sinking, but some damage has already been done. Plants are also damaged from buildings. Tundra plants are very fragile and sometimes even stepping on them can kill a population for many years. Without plant cover the tundras soil just washes away. Without plant life or soil the tundra's land cannot support life.