In this paper, they discuss how regional emissions trading schemes can impact businesses and pollution levels. The European Union and Australia have put in place methods to handle concerns about competitiveness and pollution leaks. They focus on giving free carbon allowances to certain industries to balance things out. Both regions use different ways to distribute these allowances, which could cause issues when trying to connect their trading systems together. While it is technically possible to link these systems, the differences can lead to problems with effectiveness, fairness, and the environment.