Volume 13 Issue 9, September 2023

Climate change research and assessments, including the most recent IPCC report, paint an increasingly dire picture of the future. However, the assumption that the future will be worse than the present may be wrong for many aspects of human well-being.

The IPCC has been successful at building its scientific authority, but it will require institutional reform for staying relevant to new and changing political contexts. Exploring a range of alternative future pathways for the IPCC can help guide crucial decisions about redefining its purpose.

Climate change has been identified as a driver of instability and conflict around the world. However, how climate change and the transition to a net-zero world might alter the character of military operations is often overlooked.

Inconsistent climate projections for much of the Global South from six generations of IPCC assessments have compounded the many challenges it faces in adapting to climate change. Here, we propose using emerging technologies and strengthening international collaborations to address these challenges.

There are contrasting views on how to produce the accurate predictions that are needed to guide climate change adaptation. Here, we argue for harnessing artificial intelligence, building on domain-specific knowledge and generating ensembles of moderately high-resolution (10–50 km) climate simulations as anchors for detailed hazard models.

The release of the IPCC Synthesis Report concludes the sixth assessment cycle (AR6). Nature Climate Change speaks to outgoing IPCC Chair Hoesung Lee about the reports, and the lessons that may inform the seventh assessment cycle.

Planning for climate change means accounting for melting ice and sea-level rise; exactly how much is shaped by many factors, each carrying its own uncertainties. Scientists are grappling with this uncertainty to better understand the fate of ice sheets and coastlines.

Declining snow cover poses a substantial risk for many ski resorts that often counter this trend with snowmaking, leading to increasing emissions caused by ski tourism. Research now quantifies the risks of rising temperatures to the skiing industry at the pan-European level, together with the potential and emissions of snowmaking.

Atmospheric observations can quantify anthropogenic carbon dioxide emissions, but variability in net land carbon exchange delays the detection of changes. Now, research improves understanding of this variability and allows earlier detection of emissions changes.

Satellite-based analysis indicates that the relative change in cloud droplet number concentration with relative change in aerosol concentration is sublinear, contrary to common assumptions. The revised nonlinear method predicts that in heavily polluted regions the additional warming due to improvements in air quality will occur two to three decades later than predicted by the linear method.

The stability of the West Antarctic Ice Sheet is uncertain on a rapidly warming planet. Geoengineering through solar radiation modification could halt global warming and potentially delay the demise of the ice sheet. But in high-greenhouse-gas-emission scenarios, collapse of the ice sheet ensues despite such intervention.

A network of more than 100 researchers tracked trees for up to 30 years in forest plots across South America, enabling estimation of the impacts of record temperatures and drought on carbon dynamics. The carbon sink in these forests ceased during the 2015–2016 El Niño, with drier forests losing the most carbon.

Reducing the risk of maladaptation is critical to successful climate adaptation, yet such dichotomy hampers nuanced assessments of adaptation outcomes. The authors provide a framework to assess relevant dimensions of adaptation outcomes on a continuum and apply it to various adaptation options.

Planned relocation can be an adaptation approach to avoid damages from increasing natural hazards yet concerns over maladaptive outcomes remain. Based on flood-related relocation cases, this study highlights the importance of community engagement in enabling sustainable livelihoods.

Fossil fuel companies need to align their activities with the climate goals and reduce their production rapidly. This research based on an updated methodology shows that these companies would produce more than their cumulative production budgets by 2050 if the recent trend continues.

Climate change poses a substantial challenge to ski tourism due to the strong reductions in snow cover in many mountain regions. Here, the authors assess the risks to ski resorts in 28 European countries and the potential water demand and emissions associated with snowmaking.

Cloud droplet number concentrations are often assumed to depend linearly on atmospheric aerosols (in log–log space). Here the authors show that this relationship is instead sigmoid, which delays additional warming due to air pollution mitigation by 20–30 years in heavily polluted regions.

The West Antarctic Ice Sheet is expected to collapse with warming. Here the authors assess whether solar geoengineering could prevent such a collapse and find that this would be possible only with early deployment under low and medium emissions, highlighting the need for emissions mitigation.

Verification of reported fossil fuel emissions is critical for tracking the progress of the Paris Agreement. Here, a simple model suggests the stability of the sensitivity of net carbon exchange to climate and carbon dioxide forcing and validates reported global emissions with improved accuracy.

The authors analyse tree responses to an extreme heat and drought event across South America to understand long-term climate resistance. While no more sensitive to this than previous lesser events, forests in drier climates showed the greatest impacts and thus vulnerability to climate extremes.

Using 25 years of satellite chlorophyll a data, the authors demonstrate significant and widespread changes in the amplitude, timing, duration and seasonality of Southern Ocean phytoplankton blooms. Such changes threaten ecosystem services and can impact global climate by altering natural CO₂ uptake.

The authors define the time of emergence—the time at which climate change signals emerge from the noise of ecosystem variability—for the great tit Parus major. They show that the time of emergence differs across levels, occurring earlier at the population level rather than at the trait or vital rate levels.

The authors use niche modelling and landscape genetic approaches to understand population-level climate change vulnerability for three alpine species. Their approach reveals similar population-level vulnerability for the studied keystone species and its two beneficiary species.