The phrase "planetary scale" refers to something that happens or exists on a global or worldwide level. It means it is vast and affects or involves the entire planet. Full definition
I would point out you could pick apart many of the Global Warming claims and still believe that man made pollution has a detrimental affect on a local and maybe even on planetary scale. (dotearth.blogs.nytimes.com)
So, the unwanted war at planetary scale appears because conflict is being avoided at state scale, like the political conflict. (globaleducationmagazine.com)
We're talking about altering ecosystems of planetary scale for a benefit that won't actually relieve us from dealing with all the other issues, such as conservation or alternative energy generation. (treehugger.com)