Shipboard temperature measurements are conducted worldwide, and this data covers about 70% of the world surface. The global temperatures are a combined land-sea temperature record. So, two questions: are shipboard temperature measurements indicated to be deficient compared to terrestrial stations? And why should Australia and New Zealand -- considered developed, affluent, "Western" nations -- have poorer temperature recordkeeping than the U.S. and Europe? (These are significant because they are important regions and land masses in the Southern Hemisphere, which has much less land surface compared to ocean surface than the Northern Hemisphere.)
Its a good practice to look for errors in data collection. Supposed errors have not yet been demonstrated to have a significant effect on the computed trends.
Also, last Sothern Hemisphere winter showed largest recorded area of SEA ICE, and new Sat data is showing INCREASING mass of Antarctic ice, which MORE than offsets losses in Greenland.
Two different environments. Melting of the Greenland ice sheet could cause instability and collapse there while Antarctica accretes.
Also see the reference at post 37 in this thread:
A New Record for Antarctic Total Ice Extent?
And:
What good is real data mixed with model results unless the real data is refusing to cooperate with a foregone conclusion?
One hundred years ago, ships typically lowered a bucket in the sea and then measured the temp once brought back onboard; how has the measurement technique changed since?