What "we in the first world" mostly need to concentrate on is mitigation of the effects of whatever the climate bestows upon us, there is no sense in trying to change the course of the climate. Mitigation means developing crops which will grow and prosper in areas where the conditions become more amenable to agriculture, e.g. large parts of the northern hemisphere which are now tundra might become more bountiful if the temperature goes where it was during the last interglacial and during the Holocene climatic optimum. If there is a marked rise of sea level - which is not a given, it wholly depends on where on the planet you happen to take measurements since several areas are still rising due to post-glacial rebound [1] - this can be mitigated in several ways as has been shown in the Netherlands for centuries.

It does not make sense to waste time doing penance by "reassessing out relationship with this planet" - the planet couldn't care less whether we live or die - when the capabilities of "the first world" are much better suited for developing and implementing technologies to improve the quality of life for anyone who cares to implement them. This does not mean churn out more useless commercial crap to be produced by the lowest bidder. What it means is developing and producing effective desalination systems to ensure the availability of fresh water, effective energy storage systems which actually work, can be affordably produced now in enough quantity, design and series-build nuclear (fission) power generation systems which can be delivered and installed on locations without needing to type-approve each and every installation as if it is a from-the-ground-up design, etc. Whatever impact a changing climate - whether that change means a warmer or cooler climate - has it will be worldwide but the mitigations will need to be implemented on a local/regional/national level.

So, no penance is wanted nor needed nor would that be of any help. It is good old human ingenuity which we should turn to. A species which looks towards colonising other planets should be - and is - capable of facing this much smaller challenge and emerge victoriously.

[1] https://en.wikipedia.org/wiki/Post-glacial_rebound