Net Zero Won't End Warming Inequality: Why the Tropics Face the Longest Wait
The tropics will be among the last places to feel the benefit if global greenhouse gas emissions fall to net zero, according to research published on 22 September 2026. The Guardian
Net zero, in this context, means balancing greenhouse gases put into the air with those taken out, so no extra is added.
The researchers report that temperatures have risen more in tropical areas compared with past levels than at higher latitudes, including in Europe and North America.
The work was led by Dr Andrew King and colleagues at the University of Melbourne and published in the journal Environmental Research Letters. The team ran three sets of computer models of likely temperature change if global emissions reach net zero and compared the results with countries' gross domestic product, a common measure of economic size. They found warming inequality would not reverse once emissions reach net zero. Even with net-negative emissions, which means removing more carbon dioxide than is added, a reversal could take many decades to start.
King said that "on a path close to net zero, the inequality seen in present-day warming persists indefinitely." He added that "wealthier countries that caused more of the warming problem are not those most exposed, even beyond net zero, while regions that did not cause the warming experience the most warming." He also said that "getting to net zero sooner would make long-term warming after net zero less likely and limit inequality."
Tropical ecosystems such as some coral reefs evolved in a narrower temperature range than ecosystems at higher latitudes, the researchers note, and would keep facing heavy effects for longer as emissions fall. They have less room to adjust before normal function breaks down.
A separate report released with the research connects that lasting physical effect to legal risk. The UN refugee agency found the climate crisis was increasing the risk of people becoming stateless, meaning having no citizenship in any country. The statelessness report was commissioned by the agency and released with the Peter McMullin Centre on Statelessness. It estimated about 4.5 million people were stateless but said the true number was probably much larger because stateless people are invisible to official statistics. It said the climate crisis risked creating more stateless people through displacement after climate-driven disasters such as fire, flood and sea level rise.
The report called on nations to support the continuity of statehood for countries facing extreme climate damage, including Pacific islands losing land to rising seas. It recommended helping countries digitise citizenship records and ensuring children left without parents after a disaster are given citizenship.
The next United Nations climate talks are taking place in Belem, Brazil, an Amazonian city. The World Meteorological Organisation reported record highs for atmospheric carbon dioxide. Research literature has long held that climate change is tightly coupled with patterns of inequality at both global and local scales, and that unequal access to mitigation and adaptation strategies can worsen existing social vulnerabilities and widen differences in impacts. Mitigation means cutting emissions. Adaptation means adjusting to effects already in motion.
The broader context here is diplomatic as well as climatic. Stabilising the global average does not stabilise lived risk in the same way everywhere. It is more like turning down a central heater while one room stays hot.
Looking at what this means for negotiators and planners, net zero works less like a finish line and more like the start of a long wait. If temperature differences fade slowest where incomes are lowest and past emissions are smallest, then adaptation finance, loss and damage funds, and legal questions around statehood and nationality stay relevant well after the emissions peak. For tropical states, the policy horizon extends far beyond that peak.
