The T and P at which this occurs defines the critical point which for water is some 300 degrees C and 300 atm. Note that there is one point on the diagram for water where solid, liquid and vapor are in equilibrium - triple point . Note that the Earth environment is close to the triple point and that water, steam and ice can all exist at the surface. In addition to the properties noted above, there are some other properties of water which help to explain its behavior. It takes a lot of thermal energy to heat one gram of water one degree centigrade.
Water has a high heat capacity .
Imagine a shoreline. Thus, water may remain quite cool even in the summer. Thus, water is a polar molecule . The positive end of the molecule attaches itself to negatively charged molecules, for example, which helps to promote breakdown of the solid structure. Take the Water Self-Quiz Physical Weathering Reactions at the Earth's surface tend to make large particles smaller.