An explosion in e-commerce demand is buoying the air freight business, boosting profit at some major airlines despite global trade tensions and underscoring robust consumer confidence.

Air freight demand is expected to rise 4 percent this year, the International Air Transport Association said at its annual meeting this week in Sydney.

Top beneficiaries will be freight-heavy carriers like Hong Kong's Cathay Pacific Airways, Dubai's Emirates, Germany's Lufthansa and Korean Air Lines.