While much of the academic and policy discussion has revolved around SSP1 (sustainability) and SSP2 (middle of the road), SSP4 has received disproportionately little attention in both research literature and official climate discussions. Despite its relative obscurity, SSP4 outlines one of the most plausible pathways to high climate mitigation — on par with SSP1 — while simultaneously envisioning an era of increasing inequality.

The accelerating embrace of SSP4 — intentional or otherwise — reflects a world where elites secure their future in fortress enclaves while the majority grapple with worsening inequality, climate disruption, and eroding democratic norms. Behind the veneer of occasional sustainability pledges lies a growing apparatus of private security, AI-driven surveillance, and monopolized access to critical resources, all guarded by oligarchic governance structures. In this scenario, climate action is no longer a collective human endeavor; it is an exclusive contract between the ultra-wealthy and the technologies they command.

The disparity in environmental impacts across different countries has been widely acknowledged1,2. However, ascertaining the specific responsibility within the complex interactions of economies and consumption groups remains a challenging endeavour3,4,5. Here, using an expenditure database that includes up to 201 consumption groups across 168 countries, we investigate the distribution of 6 environmental footprint indicators and assess the impact of specific consumption expenditures on planetary boundary transgressions. We show that 31–67% and 51–91% of the planetary boundary breaching responsibility could be attributed to the global top 10% and top 20% of consumers, respectively, from both developed and developing countries. By following an effective mitigation pathway, the global top 20% of consumers could adopt the consumption levels and patterns that have the lowest environmental impacts within their quintile, yielding a reduction of 25–53% in environmental pressure. In this scenario, actions focused solely on the food and services sectors would reduce environmental pressure enough to bring land-system change and biosphere integrity back within their respective planetary boundaries.

First, although most countries have committed to net zero targets, they still provide little information on what role CDR will play in reaching them. Within the NDCs, ambiguities and a lack of transparency lead to wide ranging assessments of not only the land use §ux and implied removals, but also overall emissions levels. These problems are even more apparent with the long-term strategies, which lack any common reporting structure and where underlying scenarios are illustrative rather than formal commitments.

Finally, a recurring concern in the literature is that including CDR in mitigation discussions may deter near-term emissions reductions 38. States, corporations or other interest groups seeking an excuse for doing very little may exploit the fact that CDR can compensate for emissions, overplaying the quantity of removals that may be achieved at some (later) point in time. Indeed, a variety of claims and discursive strategies beyond CDR are used to excuse or delay climate action, which may help political actors resolve the tension between powerful incumbent fossil interests and increasing domestic or international calls for
climate action.

An over-dependence on land-based removals brings risks for land
availability, food production and ownership rights.

Additionally, forest carbon is vulnerable to reversal and expectations that regional sinks can be preserved in the coming decades have been challenged, highlighting the importance of policies that promote sustainable management, prevent illegal removals, and limit the impact of natural disturbances

• The_carbon_dioxide_removal_gap.pdf