Scenario Analysis on Protein Consumption and Climate Change Effects on Riverine N Export to the Baltic Sea

Abstract

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.

A Study of Climate Change and Cost Effective Mitigation of the Baltic Sea Eutrophication

“…Furthermore, most studies calculate the impact of climate change only on nitrogen load to the Baltic Sea. Data from [5,29] is therefore used to simulate the impact of climate change on nutrient outflow in the dynamic nutrient abatement model. Both [5] and [29] use the same four climate change scenarios, which are described in [7].…”

“…Data from [5,29] is therefore used to simulate the impact of climate change on nutrient outflow in the dynamic nutrient abatement model. Both [5] and [29] use the same four climate change scenarios, which are described in [7]. All of the four climate change scenarios are produced from a coupled regional atmosphere -Baltic Sea climate model, the so-called Rosby Centre Atmosphere Ocean Model (RCAO).…”

“…In [5] the predicted change in water discharges from [7] is used to model impacts of climate change on nitrogen outflow to five of the Baltic Sea marine basins; Bothnian Sea, Bothnian Bay, Baltic Proper, Gulf of Finland and Gulf of Riga. Corresponding nitrogen loads to the Danish strait and the Kattegat marine basins are obtained from [29].…”

“…Corresponding nitrogen loads to the Danish strait and the Kattegat marine basins are obtained from [29]. However, neither [5] nor [29] model the impact of climate change on phosphorous loads to the Baltic Sea. This is made by [31] who shows that for the Finnish catchment Kokemäenjoki, climate change has an equally large impact on both nitrogen and phosphorous loads to the sea.…”

“…Climate change and structural changes in the agricultural sector are considered to be the major drivers of future nutrient loads to the Baltic Sea [5]. Climate change is expected to change the precipitation pattern in the drainage basin.…”