With international efforts on climate action still not on track to limit warming to 1.5°C, technological fixes that aim to intentionally alter the Earth’s climate, such as solar geoengineering, might seem like appealing options for tackling global warming. But they come with questions in terms of feasibility, impacts and risks, governance and geopolitics, and who may or may not benefit.

Crucially, no mature solar geoengineering technology exists today. And even if solar geoengineering was deployed, it would not reverse or halt climate change but create a different, engineered climate future.

Solar geoengineering would result in new and additional impacts on and risks to human and natural systems, mainly driven by changes in temperature, precipitation and extreme events. These would be distributed unequally, with regions already most vulnerable to climate impacts disproportionately affected.

And, as solar geoengineering does not cut emissions, non-temperature related impacts associated with continuing emissions would also continue, including ocean acidification. Also, it would put the world at risk of a sudden rise in global temperatures if solar geoengineering suddenly ends or fails – the "termination shock".

Since solar geoengineering would not affect all regions of the world equally, it could aggravate existing inequalities and regional conflicts, exacerbating the existing divide between those countries contributing most to climate change and those forced to bear the highest physical, societal and economic costs. This also raises questions around how additional adverse impacts from solar geoengineering could require new finance and support systems for adaptation and loss & damage, especially for particularly vulnerable regions.

Motivations for developing and deploying solar geoengineering could meanwhile be driven by geopolitical considerations rather than the actual risks of the climate crisis. Even the hypothetical prospect of solar geoengineering could “green light” the continued burning of fossil fuels, posing a threat to net zero commitments and other mitigation ambitions. And only major world powers have the capacity and capability to deploy solar geoengineering at scale, posing the risk of unilateral solar geoengineering deployment controlling regional and global temperatures and associated impacts and risks.

Rather than promoting potentially dangerous real-world experiments, both climate policy and action must follow the best available science, which is clear on the need for urgent and strong cuts to greenhouse gas emissions if we are to meet the Paris Agreement objectives.

Achieving net zero greenhouse gas emissions critical to limit climate tipping risks

Current climate policies are putting Earth on a path to a high risk of triggering climatic tipping points – even if temperatures return to below 1.5°C of global warming after a period of overshoot. A new study finds that the risk of crossing these thresholds increases with every additional 0.1 °C of overshoot above 1.5 °C and strongly accelerates above 2.0 °C. These risks can be minimised if stringent emissions reductions are taken in the next decade, and net zero greenhouse gas emissions are met and maintained.

Evaluating the near and long-term role of carbon dioxide removal in meeting global climate objectives

For 1.5°C pathways with limited overshoot, most of the mitigation between now and 2030 should come from emissions reductions (70%), with reductions from cutting non-CO2 emissions (20%) and land-based carbon dioxide removals such as afforestation and preventing deforestation (10%) making up the remainder.

A review of loss and damage in the Caribbean (1994 to 2024)

Loss and damage from climate change has been the lived reality of Caribbean small island developing states (SIDS) for decades. Despite efforts to adapt, it is reversing development gains, leaving lasting financial stress, and causing irreparable damage, including the loss of cultural heritage. This report is the first to provide a systematic overview of how Caribbean countries are framing and reporting on loss and damage.

Heavy precipitation hitting vulnerable communities in the UAE and Oman becoming an increasing threat as the climate warms

Researchers have assessed the extent human-induced climate change altered the likelihood and intensity of the weather conditions that caused the flooding in the United Arab Emirates and the northern parts of Oman in April 14–15 2024. The region was hit by exceptionally heavy rainfall causing massive disruption in infrastructure and public life in the area and leading to at least 20 fatalities in Oman and four in the UAE.

The 1.5°C limit and risks of overshoot

This briefing looks at what the 1.5°C limit means in terms of adaptation and loss and damage for the most vulnerable countries and regions. It finds that slowing down warming is critical to buy us time to adapt and also to avoid irreversible loss and damage. Even if warming rises above 1.5°C (overshoot) we can bring it down again with ambitious emissions reductions.

Le seuil de +1,5°C et le risque de dépassement de ce seuil

Ce rapport examine ce que la limite de 1,5 °C signifie en termes d'adaptation et de pertes et dommages pour les pays et régions les plus vulnérables. Il constate qu'il est essentiel de ralentir le réchauffement pour nous donner le temps de nous adapter et pour éviter des pertes et des dommages irréversibles. Même si le réchauffement dépasse 1,5 °C, nous pouvons le faire baisser à nouveau en réduisant les émissions de manière ambitieuse.

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Decarbonisation targets and 1.5℃ pathways

Comment

Solar geoengineering: a note to inform discussions on physical climate impacts, risks and governance issues

Publications

How can event attribution science underpin financial decisions on Loss and Damage?

Achieving net zero greenhouse gas emissions critical to limit climate tipping risks

Evaluating the near and long-term role of carbon dioxide removal in meeting global climate objectives

Increasing April-May rainfall, El Niño and high vulnerability behind deadly flooding in Afghanistan, Pakistan and Iran

A review of loss and damage in the Caribbean (1994 to 2024)

Earth Virtualisation Engines (EVE)

Heavy precipitation hitting vulnerable communities in the UAE and Oman becoming an increasing threat as the climate warms

The impacts of multiple tropical cyclone events and associated precipitation on household income and expenditures

Mapping the climate risk to urban forests at city scale

The 1.5°C limit and risks of overshoot

Hydrologic interpretation of machine learning models for 10-daily streamflow simulation in climate sensitive upper Indus catchments

Le seuil de +1,5°C et le risque de dépassement de ce seuil