Overconfidence in climate overshoot

This study in Nature show that definitions of net zero now in widespread use will not actually stop global warming. The paper demonstrates that relying on natural carbon sinks, such as in forests or oceans, to 'offset' ongoing fossil fuel emissions will lead to continued warming.

Northern forests are critical in the race to net zero CO₂ by mid-century. Protecting and restoring these forests, alongside steep and rapid reductions in fossil fuel emissions, is essential both to mitigating emissions and to supporting forest ecosystem services and biodiversity.

Seasonal forecasting of atmospheric parameters is important in various fields including agriculture. This study tests how machine learning can complement dynamic models using Tanzanian seasonal forecasts and finds this process uses far less computational power.

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.

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.

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. 

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.

The authors propose creating an international federation of research institutions that improve the quality and accessibility of Earth systems data. The purpose is to empower all people to respond to the immense and urgent challenges posed by climate change.