Scenario analysis on protein consumption and climate change effects on riverine N export to the Baltic Sea.
This paper evaluates possible future nitrogen loadings from 105 catchments surrounding the Baltic Sea. Multiple regressions are used to model total nitrogen (TN) flux as a function of specific runoff (Q), atmospheric nitrogen deposition, and primary emissions (PE) from humans and livestock. On average cattle contributed with 63%, humans with 20%, and pigs with 17% of the total nitrogen PE to land. Compared to the reference period (1992-1996) we then evaluated two types of scenarios for year 2070. i) An increased protein consumption scenario that led to 16% to 39% increased mean TN flux (kg per km(-2)). ii) Four climate scenarios addressing effects of changes in river discharge. These scenarios showed increased mean TN flux from the northern catchments draining into the Gulf of Bothnia (34%) and the Gulfs of Finland and Riga (14%), while the mean TN flux decreased (-27%) for catchments draining to the Baltic Proper. However, the net effect of the scenarios showed a possible increase in TN flux ranging from 3-72%. Overall an increased demand for animal protein will be instrumental for the Baltic Sea ecosystem and may be a major holdback to fulfill the environmental goals of the Baltic Sea Action Plan.
Department of Applied Environmental Science, Stockholm University, Stockholm, Sweden. hanna.hagg@itm.su.se
Hanna
H
Eriksson Hägg
Christoph
C
Humborg
Carl-Magnus
CM
Mörth
Miguel Rodriguez
MR
Medina
Fredrik
F
Wulff
D000818:Animals; D001272:Atmosphere / Q000737:chemistry; D057231:Climate Change; D006801:Humans; D008956:Models, Chemical; D009038:Motion; D009584:Nitrogen / Q000032:analysis*; D009792:Oceans and Seas; D011506:Proteins / Q000378:metabolism*; D045483:Rivers / Q000737:chemistry*
D011506:Proteins; D009584:Nitrogen