US exports methane to other countries…and in producing methane also exports it into the atmosphere in leaks everywhere.

Also, the 30x CO2 number for methane is a long term average over 100 years, and probably at this point inaccurate as methane amounts grow. Methane breaks down at a limited rate, and as more and more methane enters the air that rate decreases as the radicals that act upon the molecules get depleted. So not only does the 30x go up for 100 years, the 84x for 20 years and the over 100x for the first few years also go up. Which is a feedback, causes more warming and more methane and other gases. Etc., etc.