Tropics May Wait Longest for Net-Zero Climate Benefits

Published: 22 September 2026. The English Chronicle Desk. The English Chronicle Online.

The world’s tropical regions could remain among the last areas to experience the benefits of cutting greenhouse gas emissions to net zero, according to new research suggesting that the unequal effects of climate change could persist for decades even after global emissions stop adding to atmospheric carbon dioxide.

The findings highlight a significant geographical imbalance in the climate crisis. Although temperatures have increased across the planet, researchers say tropical regions have experienced warming that is particularly large relative to their historical climate. Many of the countries most exposed to these changes are also among those with lower levels of wealth and have contributed comparatively less to cumulative greenhouse gas emissions.

A team of Australian climate scientists led by Dr Andrew King of the University of Melbourne examined how global temperatures could evolve under different emissions scenarios. Their research considered three sets of computer modelling experiments and compared projected temperature changes with the gross domestic product of countries around the world.

The study found that reaching net zero would not automatically eliminate the existing inequality in warming between wealthier and poorer regions. Instead, the geographical pattern of unequal warming could continue for a prolonged period.

“If we follow a path that is close to net zero, then the inequality we see in present day warming persists indefinitely,” King said.

His research suggests that the countries and regions that have historically contributed more to global greenhouse gas emissions are not necessarily those experiencing the greatest temperature increases. Many tropical areas, particularly those close to the equator, remain highly exposed despite having contributed a smaller share of historical emissions.

The researchers also examined what could happen if the world moved beyond net zero and began removing more carbon dioxide from the atmosphere than it emitted. Such a situation is commonly described as net-negative emissions.

Under that scenario, the researchers found that the current geographical imbalance in warming could eventually begin to reverse, but the process could take many decades. The study therefore indicates that the consequences of accumulated greenhouse gas emissions cannot simply be eliminated when global emissions reach net zero.

King said the timing of the transition to net zero would be critical. The longer the world continues to release large quantities of carbon dioxide before reaching net zero, the greater the amount of long-lasting warming that could remain after emissions are brought into balance.

Even after net zero is achieved, carbon dioxide already accumulated in the atmosphere will continue to influence the climate system for a long period. This means that reaching net zero is important for limiting additional warming, but it does not immediately return global temperatures to historical conditions.

“Even when we get to net zero, we have still emitted an enormous amount of carbon into the atmosphere and its effects will continue for centuries,” King said.

The findings have particular implications for tropical ecosystems. Many ecosystems near the equator have evolved within relatively narrow temperature ranges, meaning that continued changes in temperature can place substantial pressure on species and habitats.

Coral reefs are among the ecosystems that could remain vulnerable. Reef-building corals depend on relatively specific environmental conditions, and sustained changes in temperature can contribute to stress and ecological disruption. The persistence of elevated temperatures after net zero could therefore create challenges even as the global rate of warming eventually stabilises.

The research also raises questions about climate justice. Countries that are comparatively less responsible for historical greenhouse gas emissions can nevertheless face severe effects from rising temperatures, extreme weather and ecological changes.

The unequal distribution of climate impacts has increasingly become part of international discussions about adaptation, financing and responsibility. While emissions reductions are aimed at limiting future warming, vulnerable countries also require measures that allow communities and ecosystems to adapt to changes that are already occurring.

The new study was released alongside a separate report examining another consequence of the climate crisis: the risk of statelessness.

A report commissioned by the United Nations refugee agency and produced with the Peter McMullin Centre on Statelessness at the University of Melbourne warned that climate-related disasters could increase the risk of people losing access to citizenship and legal identity.

The report examined how disasters such as floods, fires and rising sea levels could contribute to displacement and create difficulties for people attempting to prove their nationality. The problem could become particularly serious for communities in low-lying island states facing the loss of land because of rising sea levels.

The UN refugee agency estimates that around 4.5 million people are currently stateless, while acknowledging that the true number could be significantly higher because stateless populations are often missing from official records.

The report argued that climate-related displacement could make the problem more difficult to manage. When people are forced to leave their homes following a disaster, important identity documents and citizenship records can be lost or destroyed. People who cross international borders may then face difficulties proving their nationality.

University of Melbourne Associate Professor Radha Govil, one of the report’s co-authors, said there was a connection between regions facing significant climate impacts and the risks associated with statelessness.

The report called on governments to take preventative measures rather than waiting until climate-related displacement becomes a large-scale legal and humanitarian problem. Among the measures proposed was greater investment in digital systems for preserving citizenship records.

Digitising records could help protect evidence of nationality when physical documents are destroyed during disasters. Such systems could also make it easier for displaced people to establish their legal identity after moving from affected areas.

The report also highlighted potential risks facing children who become separated from their parents during climate-related disasters. It recommended safeguards to ensure children can obtain citizenship when they are left without parents or other documentation following an emergency.

Nationality laws can create additional complications where mothers and fathers do not have equal rights to pass citizenship to their children. The report warned that children could face greater risks of statelessness where mothers are unable to confer their nationality under national law.

Govil said the measures recommended by the report were practical and could be implemented before climate-related displacement creates larger problems.

The connection between climate warming and statelessness illustrates how the consequences of the climate crisis extend beyond temperature records and environmental damage. Changes in climate conditions can affect housing, livelihoods, migration, legal identity and access to basic rights.

For tropical countries, the new climate research adds another dimension to those concerns. Even if global emissions eventually reach net zero, the benefits of stabilising the climate will not necessarily be experienced equally or immediately across different regions.

The research does not suggest that emissions reductions are ineffective. Rather, it highlights the long-term consequences of accumulated emissions and the importance of reaching net zero as quickly as possible to limit additional warming.

The findings also reinforce the importance of adaptation alongside emissions reductions. Communities already experiencing substantial climate impacts may need infrastructure, financial resources and environmental protection measures even as global efforts focus on reducing future emissions.

For countries in the tropics, this could mean continuing to prepare for higher temperatures and associated environmental pressures long after global emissions begin to decline. The persistence of warming also means that climate policy cannot be measured solely by how quickly emissions fall.

The broader message from the research is that reaching net zero represents an important milestone rather than an immediate end to climate-related risks. Atmospheric carbon dioxide, ocean temperatures and ecosystems respond over much longer timescales, meaning that the consequences of past emissions can continue well into the future.

For vulnerable countries, particularly those near the equator and low-lying island states, the findings underscore the importance of combining global emissions reductions with adaptation and measures designed to protect communities from displacement and loss of legal identity.

As governments continue to negotiate climate policy, the research highlights the different timescales and geographical effects involved in the transition to a lower-carbon world. The path to net zero may reduce future warming, but the uneven legacy of past emissions is likely to remain an important challenge for decades to come.