Problem-Solution paragraph.

Global pollution is a problem which affects to all of us and can have terrible consequences. Always, but specially twentieth and twenty-first century, humans have been polluting the earth and we do nothing to solve it. We could reduce pollution by controlling CO2 emissions caused by petrol usage in factories and cars, but the problem is that petrol, nowadays, is one of the most important energy resources and it can't be limited or forbidden.
Another solution could be to investigate and discover new renovable energy resources, but they are very expensive and don't produce enough energy to be a real alternative, and finding such a powerful renovable resource would take very long.
I think the solution for that problem could be to use hybrid engines in cars, reducing that way the use of petrol, and use  natural gas as fuel in factories because it produces no wastes when it's burned, meanwhile new renovable and clean energy resources should be investigated.
Reducing, or even eliminate pollution is posible, but sometimes, enterprises are not interested in stop producing petrol because id the fuel which moves today's world and it's extremely well paid.