It is important that every target can be measured at the national or local level, but not every target can be defined globally in a meaningful way, for three distinct reasons:

i.     The starting points may differ too much across countries for a single meaningful quantitative standard at the global level; 


ii.    Some targets need to be adapted and quantified locally or may be relevant only in subsets of countries (e.g. those that refer to specific ecosystems); 


iii.   For some targets no global consensus exists today, and these still need to be negotiated, as is the case with greenhouse gas emission reduction targets. In the meantime, countries should establish their own plans and targets. 


In some cases, proposed numerical targets are presented in square brackets since these numbers are preliminary and may need to be reviewed by the corresponding technical communities.