Sea Level Rising
At present, sea levels around the world are rising. Current sea level rise potentially impacts human populations and the natural environment. Global average sea level rose at an average rate of around 1.7 ± 0.3 mm per year over 1950 to 2009 and at a satellite-measured average rate of about 3.3 ± 0.4 mm per year from 1993 to 2009, an increase on earlier estimates. Climate change
Destructive sudden heavy rains, intense tropical storms, repeated flooding and droughts are likely to increase, as will the vulnerability of local communities in the absence of strong concerted action.
Climate change is not just a distant future threat. It is the main driver behind rising humanitarian needs and we are seeing its impact. The number of people affected and the damages inflicted by extreme weather has been unprecedented. 
It has been estimated that about half of the Earth's mature tropical forests—between 7.5 million and 8 million km2 (2.9 million to 3 million sq mi) of the original 15 million to 16 million km2 (5.8 million to 6.2 million sq mi) that until 1947 covered the planet—have now been destroyed. Some scientists have predicted that unless significant measures (such as seeking out and protecting old growth forests that have not been disturbed)
Water pollution is a major global problem which requires ongoing evaluation and revision of water resource policy at all levels (international down to individual aquifers and wells). It has been suggested that it is the leading worldwide cause of deaths and diseases and that it accounts for the deaths of more than 14,000 people daily. An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children die of diarrheal sickness every day. Some 90% of China's cities suffer from some degree of water pollution, and nearly 500 million people lack access to safe drinking water. Air Pollution
Smog hanging over cities is the most familiar and obvious form of air pollution. But there are different kinds of pollution—some visible, some invisible—that contribute to global warming. Generally any substance that people introduce into the atmosphere that has damaging effects on living things and the environment is considered air pollution. Carbon dioxide, a greenhouse gas, is the main pollutant that is warming Earth. Though living things emit carbon dioxide when they breathe, carbon dioxide is widely considered to be a pollutant when associated with cars, planes, power plants, and other human activities that involve the burning of fossil fuels such as gasoline and natural gas. In the past 150 years, such activities have pumped enough carbon dioxide into the atmosphere to raise its levels higher than they have been for hundreds of thousands of years. Other greenhouse gases include methane—which comes from such sources as swamps and gas emitted by livestock—and chlorofluorocarbons (CFCs), which were used in refrigerants and aerosol propellants until they were banned because of their deteriorating effect on Earth's ozone layer. 
Oil is perhaps the most publicly recognized toxic pollutant. Large tanker accidents like the Exxon Valdez quickly become known worldwide. Events like this, where the Exxon Valdez grounded on Bligh Reef spilling nearly 11 million gallons of oil into the Prince William Sound in March of 1989, are dramatic and devastating to the entire surrounding marine ecosystem for many years. The biggest spill ever recorded happened during the 1991 Persian Gulf War when about 240 million gallons spilled from oil terminals and tankers off the coast of Saudi Arabia.
Many people don't realize that hundreds of millions of gallons each year quietly end up in our oceans by sources. The following list shows how much oil reaches our oceans from other sources.