When Jonah ran for 2 hours, burning 30 calories every hour, he burnt a total of 2*30=<<2*30=60>>60 calories.
If he had run for five hours, losing 30 calories every hour, Jonah would have burnt 5*30=<<5*30=150>>150 calories.
The difference in the number of calories Jonah would have burnt if he ran for five hours instead of 2 hours is 150-60=<<150-60=90>>90 calories.
#### 90