We absolutely need to look in both local and global perspective to measure sustainability. The local aspect refers to the added value in the local market, the jobs a product created in the area where it is produced and it should be close to where it is consumed. To guarantee sustainability, those distances should be always shorter. The global perspective, brings the bigger concept, where the climate change is happening and if we do not act sustainable we might end our geological era due to our impacts in the environment. The whole concept of sustainability relies on both perspective being considered, environmentally, socially and economically wise.
We need both a global and local perspective when measuring sustainability due to the reason that measuring sustainability is not only a contentious issue, but one which has captured the attention of both academics and politicians since the late 1980s.
Sustainability measurement needs both local and global perspective because businesses have their impact at global level, and their action needs to be accounted for at the global level in order to get the real picture about their sustainability performance.
I tend to agree with you that sustainability should be thought of in terms of its local as well as global nature, to adopt a global perspective, we need to enhance our understanding of the social, political and environmental forces that shape our existence.