Comment in 2021

Since the Paris Agreement, the impacts of 1.5 and 2 °C global warming have been emphasized, but the rate of warming also has regional effects. A new framework of model experiments is needed to increase our understanding of climate stabilization and its impacts.

Trees outside of forests are numerous and can be important carbon sinks, while also providing ecosystem services and benefits to livelihoods. New monitoring tools highlight the crucial contribution they can make to strategies for both mitigation and adaptation.

The social cost of nitrous oxide does not account for stratospheric ozone depletion. Doing so could increase its value by 20%. Links between nitrous oxide and other nitrogen pollution impacts could make mitigation even more compelling.

Transdisciplinary research is increasingly seen as critical for advancing climate change adaptation. Operationalizing transdisciplinary research in the global South, however, confronts ingrained cultural and systemic barriers to participatory research.

Local communities can play a role in helping to restore tropical peatlands by using more sustainable agricultural practices. Enhancing this role would help to address interconnected crises such as climate change, food security and environmental degradation.

Small island developing states are currently faced with two significant challenges that are more onerous due to limited financial resources: adapting to increasing climate change risk and recovering from the pandemic. Debt-for-climate swaps provide an avenue for SIDS to address these challenges.

Improved management of water has been shown to have important benefits in both climate adaptation and mitigation. Water must be explicitly considered in climate policy, on par with its energy and land siblings.

Water management in the western United States is rooted in an adversarial system that is highly sensitive to climate change. Reforms are needed to ensure water management is efficient, resilient and equitable moving forward.

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.

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.

Improving agricultural activity data is a cost-effective option for reducing the uncertainty of greenhouse gas inventories and monitoring mitigation actions, meeting multiple national data needs, and bolstering investments. It’s time to direct effort to this opportunity.

Initiatives to protect carbon sinks are crucial to mitigate climate change and avert its worst effects. Advancing the rights of women and forest-dependent communities will strengthen these initiatives and enable them to have greater impact.

Restoration of forest cover can curtail the climate crisis and provide many co-benefits, or waste limited resources. To use restoration of forest cover to its highest potential, global dynamic monitoring is needed that combines existing restoration projects with control plots and remote-sensing technologies.

Private insurance is a key component of strategies to manage physical climate change impacts, but existing scenarios used by insurers are not well suited to making business decisions. We call for a complementary normative approach, based on business objectives, that delivers actionable information to decision-makers.

Weather and climate service providers around the world are looking to issue assessments of the human role in recent extreme weather events. For this attribution to be of value, it is important that vulnerability is acknowledged and questions are framed appropriately.

The 2009 pledge to mobilize US$100 billion a year by 2020 in climate finance to developing nations was not specific on what types of funding could count. Indeterminacy and questionable claims make it impossible to know if developed nations have delivered; as 2020 passes, opportunity exists to address these failures in a new pledge.

For its green transition, the EU plans to fund the development of digital twins of Earth. For these twins to be more than big data atlases, they must create a qualitatively new Earth system simulation and observation capability using a methodological framework responsible for exceptional advances in numerical weather prediction.

Reduced complexity climate models are useful tools with practical policy applications, yet evaluation of their performance and application is nascent. We call for stakeholder-driven development and assessment to address user needs, including provision of open-source code and guidance to inform model selection and application.