Stakes are not the size of the threat. Stakes are what this specific character loses if they fail, and how much of it they have already lost by now. A global catastrophe with nothing personal attached reads flatter than a custody hearing.
Escalation means each setback costs more than the last. The reliable test is reshuffling: if you could swap the order of your obstacles and the script would still make sense, you have written repetition. Real escalation is order-locked, because each failure removes an option the next one needed.
Escalate by subtraction, not addition. Take away the ally, the money, the alibi, the second chance. Adding a bigger explosion raises volume; removing the fallback raises stakes.
The final cost should be visible from act one. Plant the thing they cannot afford to lose early and cheaply, so that when it goes, you do not have to explain why it matters.