Answer to Question 1
Examples include the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, dealing primarily with the spillage of oil, The Convention on the Law of the Sea, which helped grant individual countries more authority over the water at their coastlines, and the International Decade of Action: Water for Life, which focused on increasing water quality and availability to those who need it internationally.
Answer to Question 2
A warmer climate means more evaporation from land surfaces, plants, and water bodies, because evaporation increases exponentially with temperature. A wetter atmosphere means more and, frequently, heavier precipitation and more flood events. Aerosol particles form nuclei for condensation. The more such particles there are, the greater is the tendency for clouds to form. Anthropogenic aerosols are on the increase, primarily in the form of sulfates (from sulfur dioxide in coal), carbon (as soot), and dust. They form a brownish haze that is associated with industrial areas, tropical burning, and dust storms. The most significant impact of aerosol particles is on the hydrologic cycle. The unique size spectrum of the anthropogenic aerosols causes them actually to suppress rainfall where they occur in abundance, even though they encourage cloud formation. As they do so, the atmospheric cleansing that would normally clear the aerosols is suppressed, and they remain in the atmosphere longer than usual. With suppressed rainfall come drier conditions, so more dust and smoke (and more aerosols) are the result.