Learning Topics

Protecting The Atmosphere

In the very early days of boats and ships, sails and oars were used to propel them through the water and around our seas and oceans. These methods were replaced when steam engines were first invented.

Today however, many ships are powered by fuel that is similar to the fuel we put in our cars.  But ships engines use thousands of litres of fuel in an hour, which makes it very expensive to power a ship across the sea.  So fuel oils are used that haven’t been through the same cleansing processes as the petrol or diesel in our cars, as this means they will be much cheaper.  They are known as heavy fuel oils. 

It didn’t seem to matter that these heavy fuel oils were dirty and smelly, as ships spend most of their time at sea, and not in port when they were receiving and delivering their cargoes or passengers.  So it seemed as if people and the towns and cities in our countries weren’t affected by the heavy fuel oils. 

But now we know more about the pollutants in the air and emissions that are given out from burning heavy fuel oils in ships engines.  These are a major environmental risk to our health, and can contribute to health problems. 

IMO has been working with the people operating ships worldwide to limit the amount of air pollution ships can emit.  Over time, ships will be fitted special systems which can clean the emissions, and also new engines will be installed that emit smaller amounts of chemicals.

There are also special ‘emission control areas’ around the world where there are even stricter controls.  This includes the Baltic Sea, the North Sea and around North America.  These are in areas where there is a great deal of ship traffic or where there is a particular need to protect people on the coasts from harmful emissions from ships.

Another problem emission from ships that IMO is helping to control is CO2 – or carbon dioxide.  CO2 is also emitted from our cars, lorries, trains, planes and all forms of transport.  It is known as a greenhouse gas, which is important for helping to trap the earth’s heat and keeping the planet’s temperature at a constant level.  But the balance of gases in the atmosphere needs to be correct and controlling CO2 and other greenhouse gases can help prevent global warming and changes to the climate.

But it’s not all bad news on the CO2 front: shipping is the most environmentally-friendly mode of cargo transport per kilometre, compared with the amount of CO2 emitted by lorries, vans, trains and planes in carrying the same amount of cargo.

Shipping is responsible for only a small percentage of global greenhouse gas emissions.

You could carry out your own investigations to find out more about climate change, air pollution, and how we could all do something every day to and make the air that we breathe safer and healthier for us.  

• Think about what happens to all our rubbish. 
• How many litres of fuel does your family car hold? 
• What do you know about climate change?

Check out the Clean Air Kids Website to learn about air pollution and clean air.  You can find out about:

• Doing your bit
• Recycling waste
• Air quality
• Acid rain
• Global warming
• Ozone hole
• How to make your own recycled paper
• Games and puzzles

Check out the US Environmental Protection Agency website to learn more about climate change.

Clean Oceans

Ships need to be built to high standards and operated safely in order to prevent accidents which could pollute the seas and present a risk to life at sea.

It is also important to make sure that people working on board ships don’t do anything that could cause pollution in the sea.  This could happen when they are unloading or loading oil onto a ship, or even throwing waste overboard when the ship is at sea.

IMO has regulations that say that incidents of pollution from a ship must be reported to the nearest authority ashore. 

Unfortunately, accidents at sea can and do happen. If they do, there must be plans in place to deal with it quickly and efficiently. This is to make sure that people working on ships can be kept safe, and that the marine environment is kept as free from pollution as possible.

IMO regulations say that ships must be designed and constructed so that they protect their crew and cargo in the event of an accident.  The crew should be trained so they know what to do if there is an emergency.  And they must be able to use the life jackets and life boats or life rafts that are on ships to help save their lives.

IMO regulations also say that countries that have sea around them should have plans in case there is any oil pollution or oil spill from a ship.  These are called oil-spill response plans. 

And ships that carry oil as cargo or for fuel must have a shipboard oil pollution emergency plan.  Ships that transport chemicals must have a shipboard marine pollution emergency plan. These plans say what the crew should do in an emergency. 

IMO has worked with governments of lots of countries to make sure they have good plans for how to deal with oil and chemical spills if they happen.

Fortunately, because of all of this, the number of accidents involving oil carried on board ships has decreased considerably over the past decades, and the amount of oil spilled has fallen dramatically.

Investigate what happens when oil and water are mixed together.  You could have a go at this science experiment to understand why it is so difficult to clean an oil spill.

Dealing With Waste

People working and living on a ship create waste such as garbage and sewage.  This needs to be managed carefully to avoid pollution of the oceans and seas. Ships engines also produce waste when they are in use powering the ship around the globe.

In the past, it was thought that the oceans could absorb anything that was thrown into them.  And many items, such as paper and foodstuffs will be broken down and degraded by the seas, so they wouldn’t become a pollution problem.  But for some items, this process can take months or years. A plastic bottle thrown into the sea would take 450 years to disappear completely.

Plastics can float on the surface, pushed along by ocean currents and washed onto beaches.  Heavier garbage can sink and gather on the sea bed, creating dangers for marine life.  Fish, turtles and jellyfish can mistake bits of plastic for food. When they try to eat it they can choke and die.

Other objects, such as discarded fishing ropes and nets, can trap marine mammals. 
IMO has some regulations that ban garbage and rubbish being thrown or discharged from a ship into the sea, except for organic waste such as food scraps.  These regulations have been agreed internationally and are known as the International Convention for the Prevention of Pollution from Ships (MARPOL).

Other IMO regulations prevent pollution of the seas with sewage from ships. Raw sewage looks dreadful and can create a health hazard, as well as leading to oxygen depletion with an effect on marine plant and animal life.

Far out to sea, the oceans themselves are able to break down and deal with raw sewage, through natural bacterial action. So the IMO regulations don’t allow sewage to be discharged from ships into the sea if they are too near the land, unless they have their own sewage treatment plant on board the ship. 

Some cruise ships have very sophisticated sewage treatment plants on board, so that water can be recycled and reused.

We can all help the environment by re-cycling things we use, by re-using them, and by reducing our use of disposable materials.  The crew on board ships are encouraged to do this as well.  And Governments around the world have a duty under the IMO to provide facilities within each port to receive any garbage, sewage or oily engine waste.  These are called Port Reception facilities.

Have a look at this article about dealing with waste and garbage at sea.

Things You Could Do...

• List as many types of garbage that you can think of that might end up in the sea.
• Against each type, say how you think it got there.
• Produce a poster or powerpoint presentation about this.