Sustainable Development Goals (SDGs): Are we successful in turning trade-offs into synergies? | Humanities and Social Sciences Communications

Interactions within SDGs

Each SDG in itself is an umbrella term that can be multi-faceted and contain numerous policy goals (United Nations, 2015). For example, SDG 7 (Affordable and clean energy) calls for “access to affordable, reliable, sustainable, and modern energy for all”. This leads to the question of potential trade-offs and synergies also within each SDG, for instance between affordable and sustainable energy, which we address here first of all, and we examine their evolution over time. We observe a mixture of results on interactions within SDGs for the period under study 2010–2018: (i) increase in synergies, (ii) growing trade-offs, and (iii) diluting associations within an SDG (Fig. 1).

Fig. 1

Interactions within SDGs from 2010 to 2018. The color bars represent the shares of trade-offs (orange), synergies (green), and not-classifieds (yellow) observed within a goal. The gray bar depicts insufficient data for the analysis

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The majority of goals show synergies between their component sub-indicators that are relatively stable over time. Interestingly, regarding SDG 1 (No poverty), SDG 2 (Zero hunger), and SDG 5 (Gender equality) they have emerged only recently. Before 2016, only weak associations can be observed within these goals. Interactions within SDG 5 have even flipped for a share of trade-offs to synergies between 2016 and 2017. In SDG 2, a mixed share of synergies and trade-offs are observed after 2016, with an increased share of synergies and decreased share of trade-offs. This is a positive sign for a successful implementation of the 2030 Agenda.

Trade-offs are prevalent in particular for SDG 13 (Climate action) and SDG 7 (Affordable and clean energy), illustrating the difficulty in aligning even the components within a single goal. In the case of SDG 7 these trade-offs have only emerged in 2017 while before the components were in a synergetic relationship with each other. Similarly, for SDG 11 (Sustainable cities and communities) mostly weak associations are observed before 2017 that have given way to trade-offs in the recent past. These results illustrate that for certain goals new challenges have arisen regarding successful SDG implementation.

Finally, interactions within many SDGs show that the associations among the indicators have been diluted across time, e.g., within SDG 3 (Good health and well-being), SDG 4 (Quality education), SDG 6 (Clean water and sanitation), SDG 8 (Decent work and economic growth), SDG 10 (Reduced inequalities), SDG 16 (Peace, justice and strong institutions), and SDG 17 (Partnerships for the goals). In these cases, shares of synergies have mainly been reduced by increases in shares of not-classified associations in these goals. Such diluting associations show the difficulty of maintaining intra-goal synergies, and might also be due to disproportional progress towards the goals and their targets among the countries.

Interactions between SDGs

Changes in synergies between SDGs

We turn to interactions between the SDGs and examine 136 SDG pairs over 9 consecutive years, which can be classified into changes in (section “Changes in synergies between SDGs”) synergies, (section “Changes in trade-offs between SDGs”) trade-offs, and (section “Changes in strength of associations between SDGs”) strength of associations. Figure 2 displays the significant increases in the share of synergies (left) and the significant decreases in the share of synergies (right). Between 2010 and 2015, we observe an increase in a share of synergies for nine SDG pairs. This finding is driven by two mechanisms: (i) a decrease of trade-offs and (ii) a strengthening of associations. For example, the indicators for SDG 2 and SDG 6 shows an increase in synergies mainly due to the breaking away of trade-offs. Both SDGs were also part of the MDGs and many countries have made progress on these goals during the MDG period, which might contribute to this increase in synergies. Another such positive example can be seen in the interactions between SDG 13 and SDGs 6, 7, 9, 11, and 16. A large share of trade-offs was converted into synergies in the recent years because of efforts to reduce emissions per capita and reconcile climate action with economic and social outcomes. However, many significant trade-offs remain, as well as in fact a long way to go to meet the well below 2 °C global warming target. Meanwhile, a strengthening of positive associations can be observed, for example, between SDGs 5 and 16.

Fig. 2

Changes in synergetic association among the SDGs with an increased share of synergies (left) and a decreased share (right). The color bars represent the shares of trade-offs (orange), synergies (green), and not-classifieds (yellow) observed within a goal. The gray bar depicts insufficient data for the analysis

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During the same period, we observe a higher number of 15 SDG pairs with a decrease in a share of synergies compared to the nine SDG pairs with an increase in synergies. In most cases, synergies have decreased due to diluting associations between SDG pairs. For example, SDG pair 3–7, 4–7, and 8–16 has shown almost 100% synergies in 2010, which has been reduced to <50% by 2018. This might be alarming in two senses: (i) positive associations might be vanishing and negative ones might be building up and (ii) countries might be having different paces in attaining the SDGs that can increase inequalities between the countries. Increases in trade-offs with a decrease in synergies can already be observed for several SDG pairs, i.e., 1–16, 3–7, 4–7, and 11–17.

Changes in trade-offs between SDGs

Following on a decrease in share of synergies, we observed an increase in the share of trade-offs (Fig. 3). In line with the previous sub-section, the number of SDG pairs where trade-offs are increasing (15) is higher than those which are decreasing (9). In most of cases, the mechanism underneath the deterioration is that weak associations among the goals have evolved to trade-offs, e.g. SDG pairs 1–7, 1–15, 8–15, 15–16. These trade-offs are particularly alarming and could hinder the achievement of SDGs. Therefore, a deep investigation for the caused for this is needed in future in-depth research. A good news is reducing trade-offs between some SDGs in this decade, mainly between SDG 13 and SDGs 1, 2, 3, 4, and 5. In this case, trade-offs have been converted to either synergies or weak associations.

Fig. 3

Changes in conflicting associations among the SDGs with an increased share of trade-off (left) and a decreased share (right). The color bars represent the shares of trade-offs (orange), synergies (green), and not-classifieds (yellow) observed within a goal. The gray bar depicts insufficient data for the analysis

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Changes in strength of associations between SDGs

Between 2010 and 2018, we also observed an increase in weak association among 36 SDG pairs (Fig. 4). Most cases are of weakening synergies among the SDG pairs. For example, SDG pairs 1–2, 1–3, 1–4, 1–6, and 1–10 have mostly synergistic relations (a share of more than 66%) in the beginning of the decade, however, the share has decreased up to 40% in these goal pairs, sometimes with an appearance of trade-offs. Nevertheless, weakening of trade-offs has also been observed for some SDG pairs, e.g., 1–14, 2–3, 2–7, 4–5, 2–11, 5–6, and 10–14.

Fig. 4

Changes in strength of associations among the SDGs with an diluted association (left) and a strengthened one (right). The color bars represent the shares of trade-offs (orange), synergies (green), and not-classifieds (yellow) observed within a goal. The gray bar depicts insufficient data for the analysis

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By contrast, for some SDG interactions the associations, strengthened relations can be observed over time. These are due to an increase in synergies, trade-offs or both. For example, SDG pairs 4–8, 6–9, 6–16, and 7–8 shows strengthening synergistic associations, while associations between SDG 15 and SDGs 2, 3, 9, 11, and 17 evolve toward an increase in trade-offs. For the pairs, SDGs 2–8, 2–16, 6–15, 7–15 and 13–15, both share of synergies and trade-offs increase between 2010 and 2018.

Interactions in the projected SDG trends until 2030

Looking ahead to the year 2030, the question arises how the performance on the SDGs will evolve over time and in particular the interactions between them. Figure 5 displays the results from the first interaction analysis of future SDG trends based on a projected trend variable that extrapolates the development in each country and goal from 2010 to 2015 up until the year 2030 and crucially relates it to the level needed for SDG achievement by then (as opposed to a mere extrapolation).

Fig. 5

Interactions between sub-indicators within (left) and between (right) projected SDG trends until 2030. The color bars represent the shares of trade-offs (orange), synergies (green), and not-classifieds (yellow) observed within a goal. The gray bar depicts insufficient data for the analysis. The numbers in the boxes represent the number of data pairs used for each analysis. Icon images courtesy of United Nations

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In line with our analysis in the section “Interactions within SDGs”, we begin by examining the sub-indicators within each SDG (Fig. 5, left), since they are often multi-faceted goals in themselves. With regard to the projected developments until 2030, the largest trade-offs that will need to be solved within the SDGs concern SDGs 2 (Zero hunger), 11 (Sustainable cities and communities), and 14 (Life below water). By contrast, the most synergetic elements are to be found within SDGs 3 (Good health), 7 (Affordable and clean energy), 8 (Decent work and economic growth), 9 (Industry, innovation, and infrastructure), and 16 (Peace, justice, and strong institutions). No results can be obtained here for goals that have insufficient trend data (SDG 10 and 12), or contain only one trend indicator (SDG 1 and 13), respectively.

Figure 5 (right) shows the interactions between projected SDG trends until 2030. It turns out that SDG 1 (No poverty) will have the most synergetic relationships with other SDGs on our way to 2030. We also expect SDGs 3 (Good health), 7 (Affordable and clean energy), 8 (Decent work and economic growth), and 9 (Industry, innovation and infrastructure) to have significant synergies with the other goals. The strongest mutually reinforcing relationships in our projections are between the following SDG pairs: 1–3, 1–7, 1–8, 1–9, and 8–9. Poverty alleviation and strengthening the economy, rooted in innovation and modern infrastructure, therefore continue to be the basis upon which many of the other SDGs can be achieved. However, trade-offs are still strongest for SDG 11 (Sustainable cities and communities) followed by SDGs 14 (Life below water), 16 (Peace, justice, and strong institutions) and 17 (Partnerships for the goals), and 13 (Climate action). In particular, the SDG pairs 9–11 and 11–13 constitute large trade-offs. This finding emphasizes the need to invest in research to foster innovations that can make our cities and communities more sustainable, as well as climate-friendly.

We extend the analysis of interactions between the projected SDG trends by examining high-income countries (HICs) (Fig. 6), middle-income countries (MICs) (Fig. 7), and low-income countries (LICs) (Fig. 8) separately. When examining the sub-indicators within each SDG (left-hand side of Figs 6–8), it becomes evident that the overall picture is very similar across all income groups: Countries will face similar challenges with regard to intra-goal consistency regardless of their current stage of development. The only notable differences concern SDGs 6 (Clean water and sanitation) and 15 (Life on land). For SDG 6, no synergies can be observed for HICs but their share rises for MICs and especially LICs. This finding lends support to the notion that as countries develop, the pressure to provide accessible and yet sustainable water systems will intensify in the future. By contrast, HICs show synergies regarding SDG 15 that are weaker for MICs and almost non-existent for LICs. Biodiversity protection is therefore beginning to pay off in developed regions, while the conditions for Life on land are projected to become more difficult especially in MICs and LICs. This finding sheds a light of urgency onto current public discussions around protecting green spaces, such as the Amazon forest versus economic interests.

Fig. 6

Interactions between sub-indicators within (left) and between (right) projected SDG trends until 2030 for high-income countries. The color bars represent the shares of trade-offs (orange), synergies (green), and not-classifieds (yellow) observed within a goal. The gray bar depicts insufficient data for the analysis. The numbers in the boxes represent the number of data pairs used for each analysis. Icon images courtesy of United Nations

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Fig. 7

Interactions between sub-indicators within (left) and between (right) projected SDG trends until 2030 for middle-income countries. The color bars represent the shares of trade-offs (orange), synergies (green), and not-classifieds (yellow) observed within a goal. The gray bar depicts insufficient data for the analysis. The numbers in the boxes represent the number of data pairs used for each analysis. Icon images courtesy of United Nations

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Fig. 8

Interactions between sub-indicators within (left) and between (right) projected SDG trends until 2030 for middle-income countries. The color bars represent the shares of trade-offs (orange), synergies (green), and not-classifieds (yellow) observed within a goal. The gray bar depicts insufficient data for the analysis. The numbers in the boxes represent the number of data pairs used for each analysis. Icon images courtesy of United Nations

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Turning to interactions between projected SDG trends until 2030 by income group (right-hand side of Figs 6–8), we see again a similar picture overall for all stages of development. It becomes evident, however, that for certain goals the share of projected trade-offs is lower compared to MICs and especially LICs. This is especially true for SDG 6 (Clean water and sanitation) and SDG 13 (Climate action). In other words: The pressure on pursuing climate action as well as clean water and sanitation that is not detrimental for achieving the other goals is likely to rise especially for LICs in the coming years. Unless HICs provide the technical and financial assistance necessary to let LICs benefit from state-of-the-art solutions in this regard, the development gap will rise even more at the expense of the planet and all its inhabitants—rich and poor.