I look at as as Climate change being caused by air pollution (of CO2 & certain other gasses). The old fashioned air pollution is more localized, but isn't completely localized - acid rain was/is a regional air pollution issue for example. Some of the particulates generated on the other side of the world certainly do travel here on air currents, not in high amounts, but if they carry potent pollution items, it may have some effect.

Another issue is that agricultural and sea food products sourced from polluted nations may carry the pollution with them, needing increased monitoring of imports.