Could you check if there aren't any mistakes there?
SPEECH ABOUT ENVIRONMENTAL PROBLEMS.

One of the biggest environmental problem is litter. We produce lots of domestic waste and rubbish, which we put into one bin and don't care what happens with them later. When we walk down the street in the city, we can see thousands of chewing gums on the grass, bottles or even paper dishes from fast food restaurants. The effect of this behaviour is inter alia increasing urban pollution. We don't realize that this, what we see it's only is only a part of spreading dirt. This dirt is bigger. It's in the air, water and in the ground. We can reduce it by sorting out our rubbish, not leaving litters on the streets and recycling.
Another problem is destruction of the ozone layer. Ozone layer is a thin shield high up in the sky. It protects life on Earth from the sun's ultraviolet (UV) rays. We destruct it by using areosol sprays. Poisonous substances from them and from fridges are going up into the atmosphere. Because of this more and more people get a skin cancer. To protect us from UV rays we should use sunscreens in the summer and start buying nonareosol sprays.
The same important problems are deforestation and illegal hunting. By doing this spieces are endengered and animals are losing their habitat. People hunt for animals' fur or tusks and cut down trees to get the wood. We should plant more trees, don't buy products made of tropical hardwoods and recycle paper. We can also raise public awareness by campaigns, maybe some lessons at school to inform people how serious it is. The last problem are acid rains. Acid gases are produced when fossil fuels like coal and oil are burned in power stations, factories and in our own homes. When they mix with the clouds it can cause rain. Acid rain. By them the water supplies are polluted and trees are damaged. We should use uleaded petrol, use filters in factories and reduce use of cars. But the most important thing to help our environment is desire. Without it we won't do anything.

Question

Could you check if there aren't any mistakes there?
SPEECH ABOUT ENVIRONMENTAL PROBLEMS.

One of the biggest environmental problem is litter. We produce lots of domestic waste and rubbish, which we put into one bin and don't care what happens with them later. When we walk down the street in the city, we can see thousands of chewing gums on the grass, bottles or even paper dishes from fast food restaurants. The effect of this behaviour is inter alia increasing urban pollution. We don't realize that this, what we see it's only is only a part of spreading dirt. This dirt is bigger. It's in the air, water and in the ground. We can reduce it by sorting out our rubbish, not leaving litters on the streets and recycling.
Another problem is destruction of the ozone layer. Ozone layer is a thin shield high up in the sky. It protects life on Earth from the sun's ultraviolet (UV) rays. We destruct it by using areosol sprays. Poisonous substances from them and from fridges are going up into the atmosphere. Because of this more and more people get a skin cancer. To protect us from UV rays we should use sunscreens in the summer and start buying nonareosol sprays.
The same important problems are deforestation and illegal hunting. By doing this spieces are endengered and animals are losing their habitat. People hunt for animals' fur or tusks and cut down trees to get the wood. We should plant more trees, don't buy products made of tropical hardwoods and recycle paper. We can also raise public awareness by campaigns, maybe some lessons at school to inform people how serious it is. The last problem are acid rains. Acid gases are produced when fossil fuels like coal and oil are burned in power stations, factories and in our own homes. When they mix with the clouds it can cause rain. Acid rain. By them the water supplies are polluted and trees are damaged. We should use uleaded petrol, use filters in factories and reduce use of cars. But the most important thing to help our environment is desire. Without it we won't do anything.

Answer

As I promised=)Good luck!!!
first part
To begin with, one of the biggest environmental problem is  pollution. We produce lots of household waste and rubbish, which we deposit  in one bin and don't care what  will happen with them later. When we walk down the street in the city, we can see thousands of chewing gums on the grass, bottles or even paper dishes from fast food restaurants. Most of the rubbish collected from the city is dumped in landfill sites. Factories pump industrial waste into rivers, lakes or seas. We don't realize that this, what we see,  is only a part of spreading pollution. This pollution is a huge one. It's in the air, water and in the ground. We can reduce it by sorting out and recycling our rubbish, not leaving litter on the streets. We should all make a point of putting a newspaper and glass bottles in a recycling bin. 
Secondly, another problem is destruction of the ozone layer. Ozone layer is a special type of oxygen around the Earth. It protects life on Earth from the ultraviolet radiation which comes from the sun. We damage it by using aerosol sprays and other chemicals. They make huge holes in it. Poisonous substances from this chemicals and from fridges are going up into the atmosphere. As a result, more and more people get a skin cancer. To protect us from UV radiation, we should use sunscreens in the summer and start buying non-aerosol sprays.

Answer

second part
In addition, the same important problems are deforestation and illegal hunting. The fines for illegal hunting are not high enough. People hunt for animals' fur or tusks and cut down trees to get the wood. Because of this, spieces are endangered and animals are losing their habitat. To help protect endangered species, we should establish more wildlife reserves, as the main point of a wildlife reserve is that animals live in their natural habitat. Deforestation is causing great damage to many of the world’s rainforests. We should plant more trees  and shouldn’t buy  products made of tropical hardwoods. We can also raise public awareness by campaigns or some lessons at school to inform people how serious it is. 
Finally, the last problem are acid rains. They are extremely harmful to our planet. Acid rains are caused by cars and lorries, factiries  and power stations. In recent years, we have used more and more fossil fuels to provide energy for our homes and business. When fossil fuels are burnt they release gases called sulphur dioxide and nitrogen oxide into the atmosphere. These gases mix with water to form clouds of dangerous acids and then the rain falls from this  clouds. Acid rain damages many different kinds of plants, including the crops and trees which provide us with food. It also pollutes our lakes and streams, and consequently the fish and the animals that drink it. Various species of plants and wildlife are in danger of becoming extinct as a result of acid rain. To prevent  acid rain from completely destroying our planet, we must cut down as much as possible on our use of fossil fuels. We should  find alternative forms of energy, such as solar power, to supply our homes and business. Moreover we should  use uleaded petrol, use filters in factories and use public transport instead of private cars.
To sum up all of this, I would like to say that our planet plays really very important part in our life and the most important thing to help our environment is our desire. We should do all our best to prevent it from any pollution and to keep it clean and healthy. Because without it we won't do anything. I also support Tony’s Follari quotation : “If you poison the environment,  the environment will poison you”.

Answer

Hi=)In the fifth sentence you should use only (is only) and comma after see and also you would better use the word pollution instead of dirt. In the forth sentence of the second paragraph you would better use damage instead of destruct. You should also change the forthh sentence of the third paragraph - We should plant more trees, recycle paper, and we shouldn't buy products made of tropical hardwoods. It would be a good idea for you to use a wide variety of linking words such as To begin with...In addition...Secondly..To sum up all this. I can do it if you want, but I need some time. In general your work  is great =)