Final answer:
Transborder environmental impacts occur when environmental issues affect multiple countries, but heavy traffic causing semi-global warming does not represent a recognized environmental concern compared to other transborder issues listed.
Step-by-step explanation:
Transborder environmental impacts occur when environmental issues in one country have effects in another country. Situations where this can happen include follow except when heavy traffic between two or more countries creates semi-global warming. This particular statement does not accurately reflect a recognized environmental issue, whereas other options represent real scenarios. For instance, the production of exported products can degrade the local environment, industrial production in one country can result in acid rain affecting another country, and pollution from an upstream user can affect a shared watershed, which are all real cases of transborder environmental impact.