TORNADOES
Just a small example of the adverse effects caused by global warming we've noticed is an increase in tornadoes and tropical storms. This is a result of various methods. The storm and tornado seasons are made longer. The area where they can take place is increased. Their intensity can be increased greatly.
How does this happen, you might ask? Simple. All it takes is a rise in sea temperature to set off these effects. This means that even a change that may seem unnoticeable can cause drastic problems. And what better force could there be to increase sea temperature than global warming? It's just another less-than-obvious sign of global warming. Even an interviewed expert admitted to not knowing what effect global warming has on tornadoes.