Hi I just found the NOAA table. It clearly shows that the N. hemisphere has warmed much more than the southern hemisphere since 1880!
https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202113
What could be the reason for this? My idea is that the N. hemisphere has accumulated significantly more continental mass, while the S. hemisphere is almost continent-free. And the water is warming because the Gulf Stream is currently flushing more warm water northwards. Is my idea correct? Do you have other suggestions or are there suitable papers?