Volume 13 Issue 5, May 2023

Loss and damage funds are intended to support low-income regions experiencing impacts of human-caused climate change. Currently, event attribution should only play a limited role in determining loss and damage spending, but this role could grow as the field advances.

An immediate and rapid reduction in global emissions is required for many reasons. Integrated research supports the economic case for strong near-term climate action, even before accounting for expected negative impacts on biodiversity, health and tipping points.

Strong positive wetland methane climate feedbacks from global warming may occur but have not been accounted for in Earth system models. Now, model simulations show a substantial increase in methane emissions due to the stronger impact of warming over tropical wetlands.

The speed at which terrestrial organisms are shifting their ranges in response to climate is consistently lower than that predicted by models. However, the use of microclimate-based, rather than macroclimate-based, predictions virtually eliminates these discrepancies.

Global runoff increases with carbon dioxide (CO₂) concentration because of the synergistic effects of physiological responses to CO₂ and the responses of vegetation and soil moisture to CO₂-induced climate change. These land surface changes are far more important than the direct effects of climate change on global runoff in a CO₂-warmed world.

A statistical analysis of data from global surveys reveals that soils react to the number of stressors as well as to the individual stressor types. Moreover, the increasing number of stressors above a critical threshold reduces soil biodiversity and impedes the delivery of various ecosystem processes.

Atmospheric methane concentrations are increasing and a process-based model now estimates greater methane emissions from wetlands since 2007 than previous studies. Substantial increases in 2020 and 2021 contributed to record-high growth rates in the atmospheric methane burden.

Cost-benefit analysis of climate change depends heavily on the damage function used, and it is difficult to get credible information. Multimodel comparison with newly developed bottom-up damage functions indicates the optimal temperature could be much lower than previously estimated.

Global runoff is subject to multiple influences with high uncertainties in its projections. The authors show that global runoff is expected to increase mainly due to vegetation and soil moisture responses to rising CO₂ and radiative forcing, rather than through direct effects of climate change.

Environmental drivers of soil carbon and its sensitivity to warming are poorly understood. The authors compare soil samples of paired urban and natural ecosystems and show that under warming, the microbiome is an essential driver of soil carbon in urban greenspace compared with natural ecosystems.

Northern peatland carbon sink plays a vital role in climate regulation. Here, the authors show that wildfire reduced peatland carbon uptake and enhanced emissions from degraded peatlands; climate change impacts accelerated carbon losses where increased burn rate and severity reduced carbon sink.

Warming reduces the greenhouse gas sink of pristine wetlands. Here the authors show that carbon dioxide emissions increase in cryptogam sites at higher latitudes, while methane and nitrous oxide emissions are enhanced in vascular-plant-dominated permafrost wetlands.

Using a trait-based model that resolves key zooplankton groups, the authors reveal future shifts to food webs dominated by carnivorous and gelatinous filter-feeding zooplankton. Subsequent decreases in food nutrition are linked to declines in small pelagic fish biomass, particularly in tropical regions.

The authors investigate relationships between various soil stressors that exceed critical thresholds and the maintenance of ecosystem services. They show that multiple stressors crossing a high-level threshold reduces soil functioning and can be consistently used to predict ecosystem functioning.

The authors model historic and current distributions of grassland and heathland plants using both macro- and microclimate data. While macroclimate models predict the need for major range shifts (14 km median), microclimate models predict much smaller shifts that more closely match observed patterns.