Current climate change reports最新文献

Purpose of Review

Extratropical jets and associated storm tracks significantly influence weather and regional climate across various timescales. Understanding jet responses to climate change is essential for reliable regional climate projections. This review serves two main purposes: (1) to provide an accessible overview of extratropical jet dynamics and a comprehensive examination of current challenges and uncertainties in predicting jet responses to greenhouse gas increases and (2) to suggest innovative experiments to advance our understanding of these responses.

Recent Findings

While successive generations of climate model ensembles consistently project a mean poleward shift of the midlatitude zonal-mean maximum winds, there remains considerable intermodel spread and large uncertainty across seasonal and regional jet responses. Of particular note is our limited understanding of how these jets respond to the intricate interplay of multiple concurrent drivers, such as the strong warming in polar and tropical regions, and the relative importance of each factor. Furthermore, the difficulty of simulating processes requiring high resolution, such as those linked to sharp sea surface temperature gradients or diabatic effects related to tropical convection and extratropical cyclones, has historically hindered progress.

Summary

We advocate for a collaborative effort to enhance our understanding of the jet stream response to climate change. We propose a series of new experiments that take advantage of recent advances in computing power and modelling capabilities to better resolve small-scale processes such as convective circulations, which we consider essential for a good representation of jet dynamics.

Purpose of Review

Climate change has profoundly impacted the Earth's atmospheric system and altered the terrestrial water cycle, reshaping the spatiotemporal patterns of hydrological extremes, including floods and droughts. This review aims to summarize recent advancements in understanding the response of hydrological extremes to climate change in both past and future.

Recent Findings

Historical floods driven by heavy rainfall are increasing, while those dominated by snow processes are decreasing, resulting in non-significant changes on a global average. Previously overestimated droughts, due to inaccuracies in hydrological modules within offline diagnostic metrics, have been corrected by advanced modeling results, also revealing minimal historical changes on a global scale. Earth system simulations project concurrent increases in both floods and droughts under future climate change scenarios.

Summary

Climate change influences hydrological extremes across various scales, with diverse spatial distributions and underlying mechanisms. Decision-makers should integrate multi-source information to enhance the monitoring and adaptation of hydrological extremes, particularly focusing on abrupt drought-flood alternations.

Purpose of Review

This paper analyses the options to broaden the base of climate finance provided by countries in a mixed-methods review. It (1) reviews Non-Annex II countries’ commitments in international agreements, declarations, and agendas; (2) provides and applies a literature-based review of criteria to identify countries’ responsibilities and capabilities to provide finance; (3) reviews institutional affiliation; and (4) reviews countries’ willingness to provide finance through their contributions to 27 relevant multilateral funds.

Recent Findings

Scaling up climate finance has been a political and operational priority for the UN climate negotiations. However, the Annex II list of countries that commit to support developing countries financially with mitigation and adaptation has hardly changed since 1992. Given countries’ diverse emission pathways and economic development as well as geopolitical dynamics, Annex II is turning into a weakness of the UNFCCC in times when developing countries’ climate finance needs are increasing.

Summary

Our largely qualitative analysis indicates that Eastern European countries, Russia, South Korea, Türkiye, Monaco, and Gulf States (including Saudi Arabia) meet many justifications for further negotiations about the expansion of the climate finance provider base. However, we argue against a continued rigid dichotomy of providers and recipients. We recommend four innovations going forward, including establishing ‘net recipients’ as a third category; this 1) broadens the base; 2) increases climate finance; and 3) could increase effectiveness and cooperation. More research is needed on the role of countries’ vulnerability and debt levels in discussions on climate finance provision.

Purpose of Review

Following a multi-scalar analytical approach, this critical literature review explores the factors that determine adaptation finance accessibility and allocation with particular attention to how the needs of climate-vulnerable communities are considered.

Recent Findings

Our review reveals that climate vulnerability is not a primary determinant in the accessibility and allocation of climate adaptation finance at inter-state, sub-national and local scales. Instead, factors such as institutional capacities and financial and political interests exert significant influence. This leads to maladaptation and multi-scalar inequities where climate finance favours relatively resilient groups across scales with less support for more vulnerable populations.

Summary

We argue that finance does not trickle down, but “ripples” within a climate finance arena – where we define the latter as a messy space of competition, negotiation and collaboration. To unlock equitable adaptation finance patterns, future research should focus on the multi-scalar configurations of adaptation finance beyond the international level and consider local and regional territorial and scalar politics.

Purpose of Review

Recent focus on loss and damage within the United Nations Framework Convention on Climate Change (UNFCCC) follows decades of demands by vulnerable countries for compensation for losses due to climate change. Reviewing recent literature on loss and damage finance, we consider how the new UNFCCC Loss and Damage Fund could be transformative for climate finance.

Recent Findings

This article reviews developments within the UNFCCC, including the creation of the new Loss and Damage Fund and changes in the broader field of climate finance. Recent literature indicates that the factors necessary for just loss and damage finance include inclusive governance, new and additional funds, purpose-made instruments and channels, direct access to funds, and burden sharing aligned with the polluter pays principle.

Summary

We overview the history of loss and damage finance, suggest five criteria that could make the Loss and Damage Fund just, and discuss four potential catalysts for just loss and damage finance: ecological and climatic impacts, institutional developments outside the UNFCCC, Global South leadership on debt justice, and legal developments. As the Loss and Damage Fund is operationalized and the need for loss and damage finance grows, scholars must continue to ask whether loss and damage finance furthers core tenets of climate justice, including forms of restitution.

Abstract

Abstract

Purpose

Eastern Africa has a complex hydroclimate and socio-economic context, making it vulnerable to climate change-induced hydrological extremes. This review presents recent research on drivers and typologies of extremes across different geographies and highlights challenges and improvements in forecasting hydrological extremes at various timescales.

Recent Findings

Droughts and floods remain the major challenges of the region. Recently, frequent alterations between droughts and floods have been a common occurrence and concern. Research underlines the heterogeneity of extremes and the impact of climate change as increased intensity and duration of extremes. Moreover, the importance of local and antecedent conditions in changing the characteristics of extremes is emphasized.

Summary

A better understanding of these drivers and how they interact is required. Observational and modeling tools must capture these relationships and extremes on short timescales. Although there are improvements in forecasting these extremes, providing relevant information beyond meteorological variables requires further research.

Abstract