In Alberta, there is a rule of law that says that either spouse, in the case of divorce and support, can file a case for the other parent to pay some amount of support for children that he or she has.
The court has the best interests of the children in mind. Unlike what you may come away with from the popular media, the children come first -- not the parents. The court has the option to make an interim ruling on child support. In other words, if you have kids that need support, you and your spouse must be accountable for them. You won't receive recompense for the support that you give.
The court has the option of issuing an interim order or a permanent order at any time. That is the risk you run if you and your spouse cannot come to an amicable understanding as far as the support of your children is concerned. There are guidelines that the judge must follow, but know that your lawyer needs to know all the details upfront so that he or she can plead your case.
If something changes, such as your employment status or your health, the court may amend the order of support and can be amenable to bringing this support down to a level that more fits your budget. On the other hand, the court will also look at your earnings, should they change and bring the level of support up, if necessary.
Having your research done in this area is vital. Having a lawyer to answer your questions can be very helpful when you are seeking a child support modification.
Source: Divorce Act of Canada, "Child support orders," accessed Oct. 05, 2015