In a press conference held by the State Council Information Office the day after the earthquake, geologist Zhang Xiaodong, deputy director of CEA's Seismic Monitoring Network Center, restated that earthquake prediction was a global issue, in the sense that no proven methods exist, and that no prediction notification was received before the earthquake. Seismologist Gary Gibson of Monash University in Australia told Deutsche Presse-Agentur that he also did not see anything that could be regarded as having 'predicted' the earthquake's occurrence.
What kind of issue is earthquake prediction? (If the question is unanswerable, say "unanswerable")
a global issue