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Many countries are relying on land-based strategies to meet the climate targets set out in the Paris Agreement, putting pressure on land resources. Here the authors show a global reduction in cropland area under current climate pledges, with implications for trade and food security.

Green subsidies (carrots) are now becoming a more politically acceptable climate policy option compared with corrective regulations (sticks). However, researcher show that carrots without quick and appropriate sticks will not be sufficient to reach the deep decarbonization goal in the long run.

Substantial investment will be required in renewables to implement climate change mitigation. Here, the authors focus on Latin America and the Caribbean and find that climate impacts on renewables would result in additional investments $12-114 billion by 2100.

In the version of this Article previously published, technical problems led to the wrong summary appearing on the homepage, and an incorrect Supplementary Information file being uploaded. Both errors have now been corrected.

Increasing climate ambition through 2030 will be crucial to limiting global peak temperature changes this century. Countries need to ratchet their 2030 pledges made in Glasgow to reduce temperature overshoot and consequently reduce the risks of irreversible and adverse consequences to natural and human systems.

Carbon dioxide emission scenarios rely on a number of assumptions about how societies will develop in the future, creating uncertainty in projections. Now, research reveals the sensitivity of emission estimates to some of these assumptions.

The authors model regional electricity grid coordination, which enables access to geographically dispersed resources. Results suggest grid integration can reduce planning uncertainty region-wide but may impact individual countries differently.

To evaluate the effectiveness of current national policies in achieving global temperature targets is important but a systematic multi-model evaluation is still lacking. Here the authors identified a reduction of 3.5 GtCO₂ eq of current national policies relative to a baseline scenario without climate policies by 2030 due to the increasing low carbon share of final energy and the improving final energy intensity.

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.

Import restrictions on deforestation-linked commodities, like oil crops, could cut land-use emissions but risk emissions leakage globally and economic losses for producers. Direct forest protection may be more effective than import restrictions.

To predict how society and political systems might actually respond to warming, upgrade integrated assessment models.

Modeling shows that an expanded set of federal and state policies beyond current policies in the US could achieve economy-wide emissions reductions of 56-67% below 2005 levels by 2035.

Energy transitions might require not only changes in fuel mix, but also consumption reduction. Using surveys of behaviour and basic human needs, new research estimates the minimum energy required for maintaining a decent living standard.

Assessments of emissions mitigation patterns have largely ignored differences in investment risk across technologies and regions. With a model accounting for such differences in the electricity generation sector, research now finds that mitigation costs are higher than with no risk variation, and highlights the importance of institutional reforms to lower investment risks.

Quantitative scenarios from energy–economic models inform decision-making about uncertain futures. Now, research shows the different ways these scenarios are subsequently used by users not involved in their initial development. In the absence of clear guidance from modellers, users may place too much or too little confidence in scenario assumptions and results.

Achieving the longer-term goals of the Paris Agreement and transformation to a low-carbon society requires an acceleration in electricity generation investment and capacity addition above that outlined in the US Nationally Determined Contribution.

To reduce emissions, countries have committed to nationally determined contributions (NDCs). However, countries are also committed to the UN Sustainable Development Goals (SDGs) and this study looks at the synergies between meeting NDCs and SDGs.

The Paris Agreement requires reaching net-zero carbon emissions, but a debate exists on how fast this can be achieved. This study establishes scenarios with different feasibility constraints and finds that the institutional dimension plays a key role for determining the feasible peak temperature.

The nationwide cost of cutting emissions can be affected by local policies. This study considers the differences across the US states, with integrated assessment model results showing that varying state policies only increases nationwide costs by about 10%.

Temperature changes as a result of climate change are expected to impact electric capacity and investment. Here, the authors show that in the United States under socioeconomic pathway 2 and RCP 8.5 mean temperature rises will drive increased electricity demand (0.5-8%) by 2100, along increases in capital investments by 3-22%.

The scale and nature of energy investments under diverging technology and policy futures is of great importance to decision makers. Here, a multi-model study projects investment needs under countries’ nationally determined contributions and in pathways consistent with achieving the 2 °C and 1.5 °C targets as well as certain SDGs.

Comprehensive policy measures are needed to close the emissions gap between Nationally Determined Contributions and emissions goals of the Paris Agreement. Here the authors present a Bridge scenario that may aid in closing the emissions gap by 2030.

Water constraints can affect plans to expand electricity capacity. This study shows that in the United States such constraints can increase the cost of electricity generation with slightly reduced electrification of end-use sectors, and can incentivize early retirement of water-intensive technologies.

The plant-by-plant retirement needs are not well-understood yet to achieve the rapid transition away from coal use. Here the authors found that operational lifetimes of existing units must be reduced to approximately 35 years to keep warming well below 2 °C or 20 years for 1.5 °C, even if no new capacity comes online.

Residual CO₂ emissions from fossil fuels limit the likelihood of meeting the goals of the Paris Agreement. A sector-level assessment of residual emissions using an ensemble of IAMs indicates that 640–950 GtCO₂ removal will be required to constrain warming to 1.5 °C.

There lacks a consistent and holistic evaluation of co-benefits of different mitigation pathways in studies on Integrated Assessment Models. Here the authors quantify environmental co-benefits and adverse side-effects of a portfolio of alternative power sector decarbonisation pathways and show that the scale of co-benefits as well as profiles of adverse side-effects depend strongly on technology choice.

Using a multi-sector model of human and natural systems, we find that the nationwide cost from state-varying climate policy in the United States is only one-tenth higher than that of nationally uniform policy. The benefits of state-led action — leadership, experimentation and the practical reality that states implement policy more reliably than the federal government — do not necessarily come with a high economic cost.

Hydropower is expected to expand in the coming decades as an attractive renewable energy source, but one that can have negative environmental impacts in sensitive ecosystems. Enhanced integration of variable renewable energy can offset hydropower expansion in some eco-sensitive river basins, but is mostly insufficient to offset the steep upward pressure on hydropower development that will be exerted by the low-carbon energy transition.

The transition to a low-carbon energy system is expected to have both pollution and health impacts, across multiple scales. This Perspective provides an overview of the factors that determine the scale and distribution of these impacts and outlines potential approaches to including health benefits in decision-making about energy transitions.

Results from four integrated assessment models show countries’ efforts to cut emissions fall towards the lower end of the social cost of carbon distribution, suggesting insufficient levels of ambition to meet the Paris Agreement goals.

Climate change may affect energy systems by altering energy consumption patterns and production potential, with varying levels of impact across regions. This review synthesizes key findings of climate impact studies in regional and global scenarios and sets the stage for future multi-model assessments to support energy planning.

Projected urban sprawl and environmental impacts of urbanization are greatest under a fossil-fuelled development shared socioeconomic pathway, according to global, high resolution urban cellular automata modelling.

In an inter-laboratory study, the authors compare the accuracy and performance of three optical density calibration protocols (colloidal silica, serial dilution of silica microspheres, and colony-forming unit (CFU) assay). They demonstrate that serial dilution of silica microspheres is the best of these tested protocols, allowing precise and robust calibration that is easily assessed for quality control and can also evaluate the effective linear range of an instrument.