I don't think anyone with financial sense is depending solely on a pension. For one thing, except in extremely rare cases, they only provide a portion of one's income. How much would his provide? If he retires or changes jobs before the standard retiring age (probably 65, but it could be later), he'll also get less. I work for a government-related entity with a pension system, and if I stayed till age 65, I'd get 50% of my salary. Are you guys okay with living on 50% of his salary? Are you sure you wouldn't breathe easier with some extra?
He may not realize that he probably has a work-sponsored 401(k) or 403(b) plan, which allows him to put extra retirement savings away in a pre-tax fund. This means that you get to save X amount of money per month (you choose how much), but his paycheck is not reduced by X amount, only by a percentage of that. For instance, if you put $1000 in the plan per month, he might see only $500 less in his paycheck. (I'm making these numbers up, but you get the theory.) He can save $18,000 per year this way. If work also offers a 527 plan, that's an extra $18,000 per year he could put away on the same kind of deal. If the work matches the amount put away, you're on easy street. However, government entities provide matches much less frequently than private companies.
If he put away money in retirement accounts now, it would have room to grow over the years, and be worth a ton more by the time retirement comes along.
Perhaps he would be open to hearing about these possibilities, which many thousands of people take advantage of. If not, that's something for you to consider — that he's not open to being careful to provide for you, as well as for himself, fully in retirement. You may wish to look for a job when your kids start school, or to re-enter your career. No one should be at the mercy of the poor financial decisions of a spouse. Since right now you're both living off one income, if you make money, you can sock the whole of it away in your own retirement accounts. (If your company doesn't offer them, at the least in an IRA.) Then you'll have a nest egg you can be sure of, and which may be very valuable to both of you in the retirement years.