Top 10 climate science insights unveiled

The 10 full list of insights:

• Overshooting 1.5°C is fast becoming inevitable. Minimising the magnitude and duration of overshoot is essential.
• A rapid and managed fossil fuel phase-out is required to stay within the Paris Agreement target range.
• Robust policies are critical to attain the scale needed for effective carbon dioxide removal (CDR).
• Over-reliance on natural carbon sinks is a risky strategy; their future contribution is uncertain.
• Joint governance is necessary to address the interlinked climate and biodiversity emergencies.
• Compound events amplify climate risks and increase their uncertainty.
• Mountain glacier loss is accelerating.
• Human immobility in areas with climate risks is increasing.
• New tools to operationalise justice enable more effective climate adaptation.
• Reforming food systems can contribute to just climate action.

Professor Laura Pereira from the Wits Global Change Institute, who contributed to the report and who is presenting at COP28 says: “Given the lack of mitigation action to date, inadequate climate commitments by developed countries, and a development model that remains coupled to carbon emissions, exceeding 1.5C is indeed fast becoming inevitable (Insight 1). However, now is not the time to succumb to a feeling of hopelessness in the face of powerful drivers leading the world towards the edge of a precipice that will see countless lives lost, homes and ancestral lands destroyed, and species never to be seen again. Rather, this is the time to find the transformative pathways that are needed to get onto a better trajectory for people and planet.”

The scientific insights of the report function as indispensable evidence for decision makers in business and policy, equipping them with the latest climate science to facilitate informed, effective decision-making on holistic climate and nature solutions, especially against the backdrop of the inaugural Global Stocktake at COP28, which underscores the pressing need for transformative actions to fulfil the Paris Agreement’s ambitions.

The report findings underscore the looming inevitability of overshooting the Paris Agreement’s 1.5°C global warming target, emphasising the urgency of a rapid and managed fossil fuel phase-out.

Pereira comments:”Some of the other insights offer important aspects that need to be considered as we confront this challenge head-on. Insight 5 emphasises how the climate and biodiversity crises are fundamentally interconnected and have to be addressed together. Insight 10 talks to the critical need for JUST food system transformations that can contribute to climate action, whilst insight 9 puts justice at the centre of operationalising climate adaptation, which is of critical in developing countries that sit at the forefront of climate injustices. In the African context, it’s also important to highlight that there is a lot of emphasis on carbon removal as an important mechanism for staying within 1.5 degrees (insight 3), but as insight 4 shows relying on natural carbon sinks is risky. ‘Natural’ climate solutions such as planting trees that sequester carbon needs to be done very carefully because of the potential for undermining ecosystems and livelihoods. For example, afforestation in grassy ecosystems (like our grasslands and savanna) might not sequester carbon effectively (as these systems store carbon below ground in the soil rather than aboveground) whilst impacting biodiversity and livelihoods such as pastoralism. So, some important caveats come from taking all of the insights together.”

Prof. Johan Rockström, Director of the Potsdam Institute of Climate Impact Research adds: “Science is clear. COP28 must be the global meeting when the world gets serious about phasing out fossil-fuels. Dubai is the grand mitigation moment for coal, oil and gas, which need to shift from increasing 1%/yr to decreasing globally by at least 5 %/yr, and for nature by protecting remaining carbon sinks and stocks in ecosystems, plus building resilience and new carbon sinks in agriculture. So far, we have failed on both nature and energy, taking us on a dangerous path towards losing sight of the Paris Agreement target — the 1.5°C biophysical limit.”

The report also highlights the need for robust policies to attain the scale needed for effective complementary technology solutions, such as carbon dioxide removal (CDR), especially amidst emerging concerns over the future of land and ocean carbon sinks.

Dr Oliver Geden, Senior Fellow at the German Institute for International and Security Affairs and IPCC WG III Vice-Chair says: “While not a replacement for rapid and deep emissions reductions, Carbon Dioxide Removal (CDR) will be necessary to deal with hard-to-eliminate emissions and eventually to reduce the global temperature. Current CDR is predominantly forest-based, but rapid acceleration and deployment at scale of other CDR methods with permanent CO2 removal is required, supported by stronger governance and better monitoring.”

The report spotlights the urgent need for enhanced just climate adaptation strategies that proactively address simultaneous interconnected extreme events and ensure resilience for the most vulnerable. It also accentuates the critical role of food systems in climate action, which are currently responsible for approximately one third of global greenhouse gas emissions. It advocates for the rectification of existing inequalities and emphasises that policies must be adapted to regional and sociocultural contexts, to enable the establishment of just, low-carbon food systems.

As Dr Aditi Mukherji, Director, Climate Change Adaptation and Mitigation Impact Area Platform CGIAR, explains: “The intimate links between climate change mitigation and adaptation, biodiversity conservation, and broader societal needs, including food security, requires transformative change in how we jointly govern socio-ecological systems at all scales. Most importantly, due to the growing risks of food insecurity, policies and solutions must be designed and implemented with those who suffer the most.”

The 10 New Insights in Climate Science series, launched with the UNFCCC at the COPs since 2017, is a collaborative initiative of Future Earth, the Earth League and the World Climate Research Programme, synthesising the latest developments in climate change research. This year’s report represents the collective efforts of 67 leading researchers from 24 countries.

Dr Wendy Broadgate, Global Hub Director, Future Earth, concludes: “Science shows that we are heading for overshooting 1.5°C degrees. Minimising this overshoot is critical if we want to reduce risks to societies all over the world. COP28 must be the inflection point where collective action to phase out fossil fuels gathers pace.”