There are four important warning signs that should prompt you to talk to a health care provider. 1  Pain. Pain from arthritis can be constant or it may come and go. 2  Swelling. Some types of arthritis cause the skin over the affected joint to become red and swollen, feeling warm to the touch. 3  Stiffness.
There's a whole lot of water on Earth! Something like 326,000,000,000,000,000,000 gallons (326 million trillion gallons) of the stuff (roughly 1,260,000,000,000,000,000,000 liters) can be found on our planet. This water is in a constant cycle -- it evaporates from the ocean, travels through the air, rains down on the land and then flows back to the ocean.
The Hydrosphere. The world's oceans contain 97% of the water in the hydrosphere, most of which is salt water. Ice caps, like that found covering Antarctica, and glaciers that occupy high alpine locations, compose a little more than 2% of all water found on earth.