Articles in 2022

Temporarily exceeding temperature targets could increase risk of crossing tipping-element thresholds. This study considers a range of overshoot scenarios in a stylized network model and shows that overshoots increase tipping risks by up to 72% compared with remaining within targets.

Ocean carbon uptake could be affected by changes in circulation. This modelling study shows that meridional overturning circulation slowdown increases deep-ocean storage via the biological pump but decreases carbon uptake via the solubility pump, with a net reduction in oceanic uptake of CO₂.

The authors conduct a national inventory on individual tree carbon stocks in Rwanda using aerial imagery and deep learning. Most mapped trees are located in farmlands; new methods allow partitioning to any landscape categories, effective planning and optimization of carbon sequestration and the economic benefits of trees.

Accurately assessing emissions reductions for various greenhouse gases to stay within temperature targets is important. Here, an adaptive approach, based solely on observations and not on model projections, allows quantification of emissions reductions required to achieve any temperature target.

The authors analyse the impacts of drought on tree growth for various species of various ages to assess the influences of forest demographic shift on future drought responses. The increasing proportion of young trees showing greater growth reduction to drought raises concern on future carbon storage.

Climate change is expected to intensify the hydrological cycle, but how this translates into changes in river floods is not clear. Here, the authors show that changes in river flood discharge differ between flood types, with increases in rainfall-induced floods and decreases in snow-related floods.

Polarization and the resulting political deadlock have become key barriers to more ambitious climate action. Using Twitter data between Conferences of the Parties, this research identifies a trend of increasing polarization driven by growing right-wing activity alongside accusations of political hypocrisy.

The North American Pacific Northwest experienced an unprecedented heatwave in summer 2021. This study shows that atmospheric circulation features and regional soil dryness both amplified the event’s severity; future warming increases the chance of an equivalent or stronger event.

Future changes and regional differences in snowpacks are unclear. Here the American Cordillera mountain range, spanning the Americas, is estimated to lose snow faster in the southern midlatitudes—global warming should be limited to below 2.5 °C to prevent low-to-no-snow conditions across the range.

Many countries have submitted updated and new emissions reduction pledges in COP26, but further ratcheting of pledges is needed to reach the 1.5 °C goal. Ratcheting near-term ambition through 2030 could bring the largest climate benefits and avoid potential long-term temperature overshoot.

University-based energy centres play an important role in climate discourse but many are funded by fossil fuel businesses. This study shows that fossil-fuel-funded centres express more positive sentiment towards natural gas, compared to renewable energy, than those not funded by the fossil industry.

Agriculture dependent on snowmelt will face serious challenges under climate change, which increases risks for countries that import these crop products. Food security and livelihoods in countries heavily exposed to global food trade may be vulnerable even though domestic production is not affected.

The authors use a water balance approach to show that drought-driven evapotranspiration increases are widespread and depend on the magnitude of precipitation and total water shortage anomalies. Earth system models underestimate the probability of drought-driven evapotranspiration increases in drier regions.

The authors provide long-term observational evidence of an increasing trend of early summer methane emissions from a permafrost site in the Lena River Delta linked to atmospheric warming. This observed trend constitutes a major development given the thick and cold permafrost in the study area.

How sand dunes situated in arid areas change under warming is not well known. Here the authors assess predicted changes in sand-moving wind regimes and find that dune shapes, speeds and directions of movement will probably change in many regions, as well as the potential expansion of sand seas and a reactivation of currently dormant dune fields.

The National Flood Insurance Program is a key tool for managing growing flood risk in the USA. This research shows that premiums based on local risk, rather than national averages, will generate large societal benefits, and investments in large-scale adaptation infrastructure will enhance these impacts.

The authors project changes in mean thermal stress, as well as its persistence and variability. They show complex impacts on species stability but universal increases in extinction risk, and highlight the need to go beyond average-temperature-based projections of biological performance.

The authors establish machine learning models to identify multifactor tipping points of global marine phytoplankton. They show that temperature and carbon dioxide dominate risks, and project crossing tipping points in tropical area production (50%) and resistance (41%) by 2100 under high emissions.

The authors report on the metabolic sensitivities of vertically migrating oceanic species to temperature and oxygen. They show that cold, rather than warmth, acts as an energetic barrier to these species, facilitating latitudinal range expansion under changing climate.

Climate change will impact agriculture, and this study shows cropping frequency and caloric yield are negatively impacted on the global scale by warming. While cold regions will increase cropping frequency, warm regions will see greater decreases, resulting in an overall decline in production.