Solar radiation modification (SRM), is presented by some as an option that may help to limit global temperature rise. However, SRM cannot address the root causes of anthropogenic climate change – the continued emissions of greenhouse gases. Investing precious time and resources in this critical decade to explore SRM technologies distracts from the urgent need to step up mitigation efforts to halve emissions by 2030.  

This report finds that overcoming global inequality is critical for land-based mitigation in line with the Paris Agreement. We show that if sustainable development in the land sector remained highly unequal and limited to high-income countries only, global agriculture, forestry and other land use emissions would remain substantial throughout the 21st century.  

This fourth and final ZERO IN report looks at how cutting emissions this decade can limit temperature rise and other climate impacts in the near-term. It looks back to what was set out by governments in the Glasgow Climate Pact and unpacks what “enhanced mitigation ambition …. in this critical decade” must look like, based on the latest IPCC science.  

This study builds on work by Samset et al., who reported that the effects of emission mitigation will only be perceived through global temperature with a multi-decadal delay. This paper provides additional context and expresses concerns with the approach towards assessing a discernible warming response under different greenhouse gas concentration pathways.  

This study extends the framework of an existing spatially resolved, annual-scale Earth system model (ESM) emulator (MESMER) by a monthly downscaling module (MESMER-M), thus providing local monthly temperatures from local yearly temperatures. MESMER-M is able to statistically generate ESM-like, large initial-condition ensembles of spatially explicit monthly temperature fields, providing monthly temperature probability distributions which are of critical value to impact assessments.  

The contributions of single greenhouse gas emitters to country-level climate change are generally not disentangled, despite their relevance for climate policy and litigation. Here, we quantify the contributions of the five largest emitters (China, US, EU-27, India, and Russia) to projected 2030 country-level warming and extreme hot years with respect to pre-industrial climate using an innovative suite of Earth System Model emulators.  

The annual ZERO IN reports by the CONSTRAIN project provide information on scientific topics that are fundamental to the Paris Agreement, as well as background and context on new developments at the science-policy interface. This includes new insights into the complex processes represented in climate models and what they mean for temperature change and other climate impacts over the coming decades. This third report provides additional context and background on the latest IPCC report on the physical science basis of climate change (IPCC AR6 WGI), and addresses important questions around how likely we are to reach 1.5°C of global temperature increase.