Volume 11 Issue 8, August 2021

In recent decades, India has witnessed a rapid pace of migration from areas with intensive agriculture to populated megacities, which are faced with increasing threat from climate hazards. Greater attention is needed for vulnerable new migrants who lack necessary resources when designing adaptation and mitigation policies.

To align their portfolios with the Paris Agreement, investors need to know the emissions of companies they invest in. Estimating these should start from a precautionary principle that disincentivizes free-riding and protects the planet.

Litigation is growing in importance as a way to achieve mitigation and equity in the face of ongoing climate change. Research now shows that currently cases are not using the latest state-of-the-art attribution science, and doing so could improve causation determination.

The difference between tropical east and west Pacific sea-surface temperatures affects local and global climate, and most climate models suggest a weaker future gradient despite a recent observed increase. Research now suggests the recent trends are due to a transient delay in east Pacific warming driven by cold water upwelling and aerosols.

Climate change mitigation and adaptation, including through nature-based measures, are urgently needed. Now mapping and valuation of global vegetated coastal and marine blue carbon ecosystems shows how interlinked countries are when dealing with climate change.

Climate change is having a profound impact on modern agriculture and plant health. Now research suggests that while crop yields may increase at high latitudes in light of climate change, these gains could be severely impacted by parallel shifts in disease risk.

Legal cases to force governments to reduce emissions or to pursue compensation for climate change-related losses are increasing. The scientific evidence used in such cases is found to be lagging behind state-of-the-art climate science; using up-to-date methodologies could improve causation claims.

Current action is insufficient to meet both the Paris Agreement and the Sustainable Development Goals. Integrated model-based analysis shows that strong interventions across many dimensions, together with ambitious lifestyle change, are needed to enable real progress towards the UN Agenda 2030.

Extreme weather events such as heatwaves and droughts are likely to occur more often under climate change. Such events can have an indirect effect on countries through global agricultural markets and food prices; this impact is stronger for higher-income than lower-income countries.

Shipping routes through the Canadian Arctic are examined under 1, 2 and 4 °C global warming across four vessel classes, including ice breakers, Arctic community resupply ships, and passenger and private vessels. All routes show longer shipping seasons and navigability as a result of sea ice loss.

The Atlantic Meridional Overturning Circulation (AMOC) is currently strong, but transition to its weak mode could see significant changes in the climate system. This work presents an observation-based early-warning system for such transitions and shows that the AMOC may be approaching a transition.

Changes in extreme heat are often calculated as anomalies above a reference climatology. A different definition—week-day heatwaves surpassing the current record by large margins—shows that their occurrence probabilities depend on warming rate, not level, and are higher than during recent decades.

The tropical Pacific east–west temperature gradient intensified recently, but climate models do not reproduce this, and they also predict future weakening. This discrepancy is attributed to a competition between long-term weakening and transient strengthening from aerosols and ocean equatorial upwelling.

Blue carbon ecosystems take up and store substantial amounts of carbon. This represents an important ecosystem service in the context of climate change, with coastal ecosystems contributing nearly US$200 bn yr⁻¹ to blue carbon wealth.

The authors model the impact of future temperature changes on infection risk for 12 major crops from 80 fungal and oomycete plant pathogens. They find increased risk, as well as crop yield, at higher latitudes and predict major shifts in pathogen assemblages in the United States, Europe and China.