Perspectives

This Perspective maps the history of climate targets and shows how the international goal of avoiding dangerous climate change has been reinterpreted in the light of new modelling methods and technological promises, ultimately enabling policy prevarication and limiting mitigation.

In order to limit warming and the most severe consequences of climate change, net global carbon emissions must reach zero by 2050. Many ecosystems contain carbon that would be irrecoverable on this timescale if lost and must be protected to meet climate goals.

Climate change and other human activities are decreasing ocean oxygen content. This Perspective considers the limited data on effects to coral reefs, including oxygen thresholds for lethal and sub-lethal effects in coral reef taxa, and proposes key research questions to address this critical issue.

Climate change detection is confounded by internal variability, but recent initial-condition large ensembles (LEs) have begun addressing this issue. This Perspective discusses the value of multi-model LEs, the challenges of providing them and their role in future climate change research.

Flash droughts, which develop over the course of weeks, are difficult to forecast given the current state of subseasonal-to-seasonal prediction. This Perspective offers operational and research definitions, places them in the broader context of climate and suggests avenues for future research.

As tundra ecosystems respond to rapid Arctic warming, satellite records suggest a widespread greening. This Perspective highlights the challenges of interpreting complex Arctic greening trends and provides direction for future research by combining ecological and remote sensing approaches.

Climate change is likely to increase human migration, but future climate-related migration flows will depend heavily on the adaptive capacity of people living in vulnerable regions and on the border policies of potential destination countries. Current opportunities for mobility are constrained by increasingly strict border enforcement and the securitization of international migration.

Model estimates of future hydroclimate are uncertain, especially at the regional scale. This Perspective argues that constraining model runoff and its sensitivity to precipitation and temperature can greatly reduce this uncertainty and improve climate model utility in water resource applications.

In this Perspective, the authors argue that defining the climate change problem as one of decarbonization rather than emissions reduction suggests a new guiding metaphor — the global fractal — which may be a more productive conceptualization for research and policy than the global commons.

Ecosystem response to climate change will vary in amplitude and dynamically, which may not be captured in current experimental design. This Perspective presents experimental design improvements to better predict responses and thus facilitate understanding of future impacts.

This Perspective describes persecution, protection and ignorance archetypes for managing and monitoring species redistribution under climate change, and argues for global shared governance agreements to cope with species shifts into new geopolitical areas.

Top-down studies of climate change use climate projections and modelled impacts, whereas bottom-up assessments focus on the recent past and present vulnerability. This Perspective argues that these approaches must be integrated to address the needs of immediate adaptation decisions.

The Paris Agreement places new emphasis on the need to take stock of adaptation progress. This Perspective discusses the conceptual and methodological challenges associated with monitoring adaptation and provides a comprehensive framework for tracking progress among governments.

The Deep Decarbonization Pathways Project develops a framework to design low-emission development pathways. This Perspective discusses the framework and how it can support the development of national strategies to meet climate targets, as well as help achieve stakeholder engagement.

Emergent constraints can be an evaluation tool for Earth System Models. This Perspective discusses emergent constraints, how they should be assessed, and when these statistical relationships can be confirmed and used to improve understanding of the changing climate system.

Big data is increasingly popular in many research domains. This Perspective discusses where elements of big data approaches have been employed in climate research and where combining big data with theory-driven research can be most fruitful.

The Paris Agreement requires substantial changes in the land system. However, national implementation plans are vague, largely insufficient and unlikely to be fully achieved. Realistic policies require proper consideration of land-system lags.

Near-term climate predictions bridge the gap between seasonal forecasts and long-term projections. This Perspective outlines the challenges and opportunities for near-term climate prediction, highlighting the need for co-ordinated efforts to benefit society.

This Perspective synthesizes research on the origins and impacts of scientific misinformation campaigns, pointing to public inoculation, legal, political and financial strategies for countering climate change misinformation and limiting its dissemination.

Earth system models project likely future climates, however, evaluation of their output is challenging. This Perspective discusses new evaluation approaches, considering both simulations and observations, to ensure credible information for decision-making.