The regime for foreign debt is dictated by the concern for excessive indebtedness in foreign currency which can sow the seeds of instability. Take the example of the ECB the regime as is in force today.
It is no simple feat, as our current path would lead to an increase of more than 3 degrees. And we have only about a decade to take the right bold actions to meet the 1.5 degree target. There is no single tool that would enable mitigation and adaptation to climate change.