• Ilona Szabó de Carvalho, co-founder and president of the Igarapé Institute and of the Green Bridge Facility, argues that keeping global warming below 1.5 °C requires action on three simultaneous fronts: phasing out fossil fuels, ending deforestation, and scaling up natural carbon capture in forests and oceans.
• She contends that energy decarbonization alone is insufficient; protecting and restoring ecosystems such as forests, wetlands, and mangroves is essential for both emissions reduction and resilience, and must be backed by transparent finance and accountability.
• With COP30 approaching in Belém, her piece calls for an integrated, finance-backed plan that ties together clean-energy expansion, a time-bound zero-deforestation roadmap, and rigorous safeguards for community-led nature-based solutions.
• This article is a commentary. The views expressed are those of the author, not necessarily of Mongabay.

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The planet just crossed a grim milestone: last year’s global temperature averaged more than 1.5°C above pre-industrial levels, shredding our margin for error under the Paris Agreement. That doesn’t doom the goal forever, but it leaves little room for delay. Clinging to energy decarbonization alone won’t pull us back. If negotiators at COP30 in Belém want any chance of lowering temperatures below 1.5°C again, they must run three tracks at once: accelerate the phase-out of fossil fuels, lock in a time-bound roadmap to zero deforestation, and scale carbon capture from nature, especially forests, mangroves, seagrasses, and other “blue carbon” systems.

Think of Earth as a pressure cooker already running hot. Turning down one burner—the fossil-fuel flame—helps, but steam is still blasting out through land-use emissions and the loss of natural carbon sinks. The gauge is rising because we keep punching holes in the lid and letting safety valves clog. Unless we vent that pressure while cutting the flame, the whole system risks catastrophic failure.

To keep 1.5°C within reach, we need to start with the obvious: fossil emissions drive the crisis. COP30 should harden and accelerate what recent summits only began—including phasing down unabated coal, phasing out inefficient fossil-fuel subsidies, and tripling renewable power by 2030. This isn’t a vibes-based transition. Countries need near-term, sector-specific targets embedded in their nationally determined contributions (NDCs), with credible finance packages to enable grids, storage, transmission, and clean industry. These packages also translate into jobs, lights, and energy security—visible results that build public trust. The standard for credibility is simple: if a plan doesn’t align with a rapid decline in fossil demand and supply this decade, it’s a distraction.

But even perfect performance on energy won’t, by itself, keep 1.5°C within reach. Roughly a tenth of global greenhouse gases still come from deforestation, and those emissions are front-loaded. Clear a forest, and carbon stored over decades pours into the atmosphere in months. Conversely, protect and restore forests, wetlands, and coastal ecosystems, and you get additional removals and resilience benefits within years, not generations. Energy decarbonization is necessary, not sufficient.

A tributary of the Amazon. Image by Rhett Ayers Butler

Forests are the immediate test of seriousness—not only because they store carbon, but because they sustain rainfall, biodiversity, and cultures that depend on them. A credible path to zero deforestation needs a clock and a ledger, with measurable milestones, transparent monitoring, and predictable finance that rewards verified results. Brazil, home to the largest tropical forest, has signaled timelines for ending deforestation and committed to large-scale restoration of over 12 million hectares in its NDC. That ambition will falter without resources and accountability.

Parties in Belém should adopt a single, time-bound commitment to halt gross deforestation, accompanied by national trajectories and results-based finance. Instruments already exist to move money to where it changes behavior—from high-integrity jurisdictional carbon crediting and pay-for-performance partnerships to targeted enforcement against illegal clearing. Examples like the Amazon Fund and the LEAF Coalition show that these approaches can work when paired with strong safeguards.

Social science is also clear about how to ensure deforestation reductions are sustainable. Where Indigenous peoples and local communities have recognized land rights, forests are healthier and deforestation rates are lower. Aligning finance with communities that steward high-carbon ecosystems is not charity; it is the cheapest climate insurance on earth. Free, prior, and informed consent is likewise a condition for durability and justice.

The third track is the most undercounted and involves ramping-up nature-based solutions. Forests, but also mangroves, seagrasses and salt marshes capture carbon at startling rates and lock it away in soils for centuries. They also blunt storm surge, stabilize coasts, support fisheries and improve water quality, all lifelines for hundreds of millions in coastal zones. Yet they are still degraded or paved over.

Ocean, reef, forest, and mangroves. Photo by Rhett Ayers Butler

Belém is the moment to forge a blue-carbon pact and plant the seeds for a fuller roadmap at the next COP. That means establishing national targets for conserving and restoring coastal wetlands, and expanding and effectively managing marine protected areas with clear rules, adequate enforcement and genuine community co-management. It also means scaling finance through ocean restoration bonds and debt-for-nature swaps. The guardrails are non-negotiable: transparent baselines, independent verification, strong social safeguards and integration of coastal carbon into national climate plans.

None of this substitutes for deep energy decarbonization. It complements it, delivering near-term removals and resilience while we retool the energy system. Of course, ambition runs on finance. Stopping deforestation and restoring degraded lands and seascapes requires significant investment. While the needs are considerable, they pale in comparison to the damages of unchecked warming. Multilateral development banks, climate funds and export credit agencies should align portfolios with zero-deforestation and natural carbon capture priorities, using concessional capital to crowd in private investors. Corporations with land-use footprints must move from generic pledges to purchasing verified outcomes in the geographies where they operate or source.

A three-track agenda also creates space for a healthier bargain between North and South. Many countries in the Global South hold ecosystems with the greatest climate bang per buck including tropical forests, peatlands, mangroves and strong domestic reasons to protect them. When Northern partners recognize high-integrity nature outcomes within the UN climate architecture, streamline access to finance, and support monitoring and enforcement capacity, trust improves and ambition rises. For forest countries, reliable international support lowers the political and opportunity costs of changing development pathways. For donor countries, investing in nature secures large, measurable reductions and removals this decade while advancing biodiversity and adaptation goals.

Amazon rainforest. Photo by Rhett Ayers Butler

COP30 should leave Belém with three concrete packages that follow this logic without resorting to lists. It should lock in the transition away from fossil fuels by setting sectoral targets inside NDCs, phasing down unabated coal, phasing out inefficient fossil subsidies, and laying out a realistic plan to triple renewables by 2030, backed by finance for grids, storage and clean industry. It should adopt a time-bound roadmap to zero deforestation, with national trajectories, transparent monitoring and results-based finance that explicitly protects the rights of Indigenous peoples and local communities.

It should also elevate nature-based solutions on land and at sea by scaling protection and restoration of forests and coastal wetlands, expanding and effectively managing marine protected areas, integrating coastal carbon into national climate and adaptation plans, and mobilizing capital through forest and ocean restoration bonds and performance-based debt relief, all under rigorous environmental and social safeguards. Across the agenda, integrity is the through line: transparency, verification and community consent. Without those, finance will trickle, not flow, and public trust will evaporate.

This is not a contest between “technological” and “natural” solutions, or between mitigation and adaptation. The real choice is whether our response matches what science and lived experience demand. Protecting and restoring forests and oceans makes the energy transition more achievable by reducing near-term warming, delivering cost-effective mitigation and building resilience to impacts already locked in. A rapid energy transition, in turn, eases pressure on ecosystems by shrinking demand for land-intensive fuels and enabling more sustainable growth. These tracks are complementary; each strengthens the others.

When delegates arrive in Belém on November 10, they will face a compressed timeline and sky-high stakes. A diplomatic approach that couples a managed fossil fuel exit with zero deforestation and scaled nature-based carbon capture is not a soft option. It is the only plan calibrated to the world we inhabit, and to the safer, more stable world we still have time to secure.

Ilona Szabó de Carvalho is co-founder and president of the Igarapé Institute and of the Green Bridge Facility

Header image: Ocean, reef, forest, and mangroves. Photo by Rhett Ayers Butler