Analyses

The socio-political factors influencing societal responses to drought are often overlooked in risk assessments. Here, a social-environmental scenario that bridges natural and social sciences is used to analyse responses of a Southern African city to unprecedented drought.

The authors quantify the thermal tolerance of 305 populations from 61 taxa by meta-analysis. They reveal strong population-level differentiation in marine and intertidal taxa, but not terrestrial or freshwater taxa, and highlight the need to consider such variation in climate vulnerability predictions.

Natural gas is seen as a key interim fuel along the pathway to a zero-carbon energy system, yet there is some concern it may delay the transition. This Analysis estimates the life cycle emissions from gas-fired electricity and the abatement potential of different mitigation options.

Decarbonization of the aviation sector is difficult due to increasing demand and the current lack of scalable mitigation technologies. This Analysis examines pathways towards a net-zero aviation system with improved fuel and aircraft technologies, efficiency gains and contrail avoidance.

A systematic review shows that >58% of infectious diseases confronted by humanity, via 1,006 unique pathways, have at some point been affected by climatic hazards sensitive to GHGs. These results highlight the mounting challenge for adaption and the urgent need to reduce GHG emissions.

Non-CO₂ effects must be addressed for climate-neutral aviation but are currently ignored in international climate policies. The authors provide a framework with different definitions of climate neutrality, then show how technological and demand-side mitigation efforts can help to achieve these targets.

The authors link the effects of pCO₂ on marine invertebrates to the localized pCO₂ conditions of their coastal habitats. They show that responses depend on the deviation from the locally experienced upper pCO₂ level, highlighting the importance of small-scale variability and adaptation.

The authors conduct a meta-analysis to reveal mismatches in above- and belowground plant phenological responses to warming that differ by plant type (herbaceous versus woody). The work highlights a need for further research and consideration of under-represented belowground phenological changes.

There is a balance in mitigation pathway design between economic transition cost and physical climate threats. This study provides a comprehensive framework to assess the near- and long-term risks under various warming scenarios globally and in particular regions.

Climate policy analyses often ignore the possibility of progressive redistribution of carbon tax revenues and assume that mitigation cost will burden the poor in the short term. Integrated Assessment Model (IAM) estimation suggests such redistribution could reduce inequality, alleviate poverty and increase well-being globally.

Determining progress in adaptation to climate change is challenging, yet critical as climate change impacts increase. A stocktake of the scientific literature on implemented adaptation now shows that adaptation is mostly fragmented and incremental, with evidence lacking for its impact on reducing risk.

Different frameworks, most notably expert assessments from the IPCC, have been developed to determine risk from climate change over this century. Estimated risk scores quantified from the IPCC assessments show a substantial increase in global composite risk by 2100 for low and high emissions.

Analysis of 1,550 future energy scenarios finds that uncertainty in solar photovoltaic (PV) uptake is mainly driven by institutional differences in designing and modelling these scenarios, rather than PV cost assumptions. This suggests more organizational diversity is needed in IPCC scenario design.

Ambitious policy instruments are needed to support the transition to low-carbon economies. This systematic review identifies what we know about positive and negative impacts of ten selected instruments on environmental, technological and socioeconomic outcomes, and how to minimize negative impacts.

Avoided deforestation is an important part of many climate mitigation strategies, yet monitoring is needed for enforcement. Subscriptions to deforestation alerts lowered the probability of deforestation in Africa by 18%, generating a value of US$149–696 million based on the social cost of carbon.

Peatlands are impacted by climate and land-use changes, with feedback to warming by acting as either sources or sinks of carbon. Expert elicitation combined with literature review reveals key drivers of change that alter peatland carbon dynamics, with implications for improving models.

The economic optimality of limiting global warming to below 2 °C has been questioned. This analysis shows that the 2 °C target is economically optimal in a version of the DICE model that includes updated climate science, climate damage estimates and evidence on social discount rates.