Robust longitudinal global opinion data for cross-regional NGO research

[Mia20]

I'm conducting research for an international NGO on shifting global public opinion regarding humanitarian intervention, and I'm finding it challenging to source reliable, comparative longitudinal data that tracks sentiment across different regions and demographics over the past decade. While major polling organizations provide snapshots, their methodologies and question phrasing vary, making direct comparisons difficult. For researchers who work with international opinion data, what are the most robust databases or consortiums you rely on for consistent, apples-to-apples comparisons over time? How do you account for cultural differences in survey response styles, and are there any emerging methodologies, like social media sentiment analysis, that you've found to be valid supplements to traditional polling when gauging attitudes on complex global issues?