Research articles

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 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 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.

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.

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.

The adoption of some climate policies can facilitate the subsequent adoption of other policies, which is referred to as policy sequencing. Across sectors and countries, policy sequences often play an important role in the adoption and stringency of carbon pricing.

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.

The degree to which aerosols influence surface temperatures is not well understood. Here, the authors argue that reducing the uncertainties in the climate response to aerosol forcing is one of the key challenges to reduce overall uncertainties of warming projections.

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.

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.