Since the civil war in Syria broke out two years ago, the United Nations estimates that more than 6.5 million people have been displaced. Of those, approximately two million are refugees living in neighboring countries. By the end of this year, the U.N. estimates those numbers will have increased to 10.25 million displaced, with 3.45 million refugees living in nearby countries. Half the population of Syria will be in need of aid.

Right now, the U.N. puts the price tag for crisis relief inside Syria at more than $2.9 billion, and the price tag for the entire region — including aid to Lebanon and Jordan, the countries in which many refugees are living — at approximately $5 billion. That’s the largest ask for crisis relief in history. Here are resources through which you can help: