thresholds have been set for N and P fertiliser application [2]. Likewise, SDG
Indicator 14.1.1 evaluates the problem of marine eutrophication resulting from
land-based activities, including nutrient pollution [12]. Since both SDG Indicator
14.1.1 and the relevant control variables refer to the same problem of eutrophication, and particularly at the same point of the impact pathway (i.e. pressure), the PB
thresholds can be used as they are complementary to SDG Indicator 14.1.1.
Changes in land use have significant effects on several biological and ecological
systems, including climate and water. For example, changes in the area of boreal
forests particularly affect the albedo of the land surface, and changes in the area of
tropical forests specifically affect global evapotranspiration rates [2]. For this purpose, a PB called “land-system change” is suggested, which estimates the loss of
forest cover at the state point of the impact pathway (see Fig. 1). Similarly, the
SDGs report a set of indicators that evaluate the environmental problems resulting
from forest cover loss as well as loss of other biomes [12]. For instance, SDG
Indicator 15.1.1 estimates the ratio between forest and total land area, SDG
Indicator 15.1.2 measures the proportion of protected areas for terrestrial, freshwater and mountain biodiversity, and, SDG Indicator 15.4.1 estimates the land
coverage allocated for mountain biodiversity. Nonetheless, none of these SDG
indicators assesses the environmental degradation on an absolute scale. Rather, they
merely report the proportions of the protected and degraded lands.
We, hence, recommend using SDG Indicator 15.1.1 along with the threshold
proposed for the land-system change PB for estimating the loss of forest cover on an
absolute scale. However, since the PB focuses solely on the loss of forest cover,
there remains a research gap in identifying relevant thresholds for other biomes
addressed in SDG Indicators 15.1.2 and 15.4.1.
The “climate change” PB and its associated control variables emphasise that the
atmospheric CO 2 concentration and the radiative forcing from greenhouse gases
(GHGs) should be reduced to 350 ppm CO 2 (350–450 ppm) and to 1 Wm
−2
respectively (at the state point in the DPSIR impact pathway) [2]. But limiting the
atmospheric concentration to 350 ppm CO 2 is unlikely as the current values of the
control variables are 399 ppm CO 2 and 2.3 Wm
−2 [2], and the world population
and economy are still growing [21]. The IPCC therefore suggests that achieving a
concentration of 450 ppm CO 2 is more likely [21, p. 12]. On the other hand, the
SDGs present a set of SDG indicators concerned with mitigation of climate change
problems [12]. At the response point, SDG Indicator 13.1.1 estimates the fatalities
and injuries due to climate change impacts, whereas SDG Indicators 13.1.2, 13.1.3
and 13.2.1 focus on adopting policies and strategies to avert climate change
impacts. SDG Indicators 13.3.1, 13.3.2, 13.a.1 and 13.b.1 aim to strengthening
institutional, systemic and individual capacity-building to implement adaptation,
mitigation and technology transfer and development actions. In addition, SDG
Indicator 9.4.1 quantifies the carbon intensity of industries at the pressure point. In
general, except SDG Indicator 9.4.1, others focus only on averting the climate
change impacts (as seen in Fig. 1), and none of them evaluates the climate change
impacts on an absolute scale. Therefore, to our understanding, the PB thresholds
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Indicator 14.1.1 evaluates the problem of marine eutrophication resulting from
land-based activities, including nutrient pollution [12]. Since both SDG Indicator
14.1.1 and the relevant control variables refer to the same problem of eutrophication, and particularly at the same point of the impact pathway (i.e. pressure), the PB
thresholds can be used as they are complementary to SDG Indicator 14.1.1.
Changes in land use have significant effects on several biological and ecological
systems, including climate and water. For example, changes in the area of boreal
forests particularly affect the albedo of the land surface, and changes in the area of
tropical forests specifically affect global evapotranspiration rates [2]. For this purpose, a PB called “land-system change” is suggested, which estimates the loss of
forest cover at the state point of the impact pathway (see Fig. 1). Similarly, the
SDGs report a set of indicators that evaluate the environmental problems resulting
from forest cover loss as well as loss of other biomes [12]. For instance, SDG
Indicator 15.1.1 estimates the ratio between forest and total land area, SDG
Indicator 15.1.2 measures the proportion of protected areas for terrestrial, freshwater and mountain biodiversity, and, SDG Indicator 15.4.1 estimates the land
coverage allocated for mountain biodiversity. Nonetheless, none of these SDG
indicators assesses the environmental degradation on an absolute scale. Rather, they
merely report the proportions of the protected and degraded lands.
We, hence, recommend using SDG Indicator 15.1.1 along with the threshold
proposed for the land-system change PB for estimating the loss of forest cover on an
absolute scale. However, since the PB focuses solely on the loss of forest cover,
there remains a research gap in identifying relevant thresholds for other biomes
addressed in SDG Indicators 15.1.2 and 15.4.1.
The “climate change” PB and its associated control variables emphasise that the
atmospheric CO 2 concentration and the radiative forcing from greenhouse gases
(GHGs) should be reduced to 350 ppm CO 2 (350–450 ppm) and to 1 Wm
−2
respectively (at the state point in the DPSIR impact pathway) [2]. But limiting the
atmospheric concentration to 350 ppm CO 2 is unlikely as the current values of the
control variables are 399 ppm CO 2 and 2.3 Wm
−2 [2], and the world population
and economy are still growing [21]. The IPCC therefore suggests that achieving a
concentration of 450 ppm CO 2 is more likely [21, p. 12]. On the other hand, the
SDGs present a set of SDG indicators concerned with mitigation of climate change
problems [12]. At the response point, SDG Indicator 13.1.1 estimates the fatalities
and injuries due to climate change impacts, whereas SDG Indicators 13.1.2, 13.1.3
and 13.2.1 focus on adopting policies and strategies to avert climate change
impacts. SDG Indicators 13.3.1, 13.3.2, 13.a.1 and 13.b.1 aim to strengthening
institutional, systemic and individual capacity-building to implement adaptation,
mitigation and technology transfer and development actions. In addition, SDG
Indicator 9.4.1 quantifies the carbon intensity of industries at the pressure point. In
general, except SDG Indicator 9.4.1, others focus only on averting the climate
change impacts (as seen in Fig. 1), and none of them evaluates the climate change
impacts on an absolute scale. Therefore, to our understanding, the PB thresholds
Exploring the Linkages Between …
419