Do you mean 1500m at race pace? A 1500m warmup is virtually 100% aerobic. The difficulty with finding out the truth, is finding an accurate way to measure the different energetic contributions. The difficulty with getting agreement on the truth, is that the question is generally irrelevant. Getting it wrong doesn't matter, and very few care enough to actually measure it, preferring instead to faithfully cling to something they read in a book, or on the web.
If you follow this link, you can find a table (unattributed) which says that 1500m is 50% aerobic:
http://www.pponline.co.uk/encyc/aerobic-and-anaerobic-energy-systems-39444#
If you look here, you can see that a table (from Astrand 1977) indicates that a "4 minute" effort is 65% aerobic:
http://www.letsrun.com/forum/flat_read.php?thread=283441&page=0
At that time, "Tinman" accused that data of being based on an old "oxygen debt" model which overestimates anaerobic energy contributions.
Later, Perronet and Thibault used isotope tracers to measure respective instantaneous energy contributions, and published the results in 1989, in the British Journal of Sports Medicine, measuring 83% (+/- 3%) aerobic energy contribution for the 1500m.
Luckily for 1500m runners, since the races were found to be more aerobic, so was their training.