These expressions are used for summing up. They are most common in a formal style.
In conclusion, we can see that poverty is the root cause of most problems plaguing our society.
In conclusion, it is not hard to see that trained teachers are better than those who lack professional training.
To sum up: most of the committee members were in favour of the project but a few were against it.
He is lazy, he is uneducated and he is ignorant. In short, he is good for nothing.
In short, we have to decide whether fossil fuels do more harm than good.
In short, we have to choose the lesser of the two evils.