Historical N load from land to East-China sea and riverine N2O emission in East-Asia

• East-Asia is known to be a hotspot of reactive N (Nr) pollution and hence to be a biggest source of atmospheric N2O among the global regions. In the last half
  century, the use of N fertilizer in this region was rapidly growing up.

• Not only N fertilizer, various non-point source of N (N deposition, manure) have also increased with land-use change (i.e., cropland expansion). Furthermore, East
  Asia is fast urbanizing in this period, which contributed increase of reactive N as a point source to a river via wastewater release.