Suchergebnisse

Nature-based solutions (NbS) to climate change currently have considerable political traction. However, national intentions to deploy NbS have yet to be fully translated into evidence-based targets and action on the ground. To enable NbS policy and practice to be better informed by science, we produced the first global systematic map of evidence on the effectiveness of nature-based interventions for addressing the impacts of climate change and hydrometeorological hazards on people. Most of the interventions in natural or semi-natural ecosystems were reported to have ameliorated adverse climate impacts. Conversely, interventions involving created ecosystems (e.g., afforestation) were associated with trade-offs; such studies primarily reported reduced soil erosion or increased vegetation cover but lower water availability, although this evidence was geographically restricted. Overall, studies reported more synergies than trade-offs between reduced climate impacts and broader ecological, social, and climate change mitigation outcomes. In addition, nature-based interventions were most often shown to be as effective or more so than alternative interventions for addressing climate impacts. However, there were substantial gaps in the evidence base. Notably, there were few studies of the cost-effectiveness of interventions compared to alternatives and few integrated assessments considering broader social and ecological outcomes. There was also a bias in evidence toward the Global North, despite communities in the Global South being generally more vulnerable to climate impacts. To build resilience to climate change worldwide, it is imperative that we protect and harness the benefits that nature can provide, which can only be done effectively if informed by a strengthened evidence base. ; Funding Agencies|Natural Environment Research CouncilNERC Natural Environment Research Council [NE/R002649/1]; University of Oxford: John Fell Fund; Oxford Martin School

UK Natural Environment Research Council ; European Research Council Advanced Investigator Award (GEM-TRAIT) ; Nature Conservancy-Oxford Martin School Climate Partnership ; NERC ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Gordon and Betty Moore Foundation ; Sime Darby Foundation ; Project USA-NAS/PEER ; Project ReFlor FAPEMAT ; Empresa Brasileira de Pesquisa Agropecuaria - Embrapa ; European Research Council (H2020-MSCA-RISE-2015) ; UK government Darwin Initiative ; Nature Conservancy ; UK Natural Environment Research Council (NERC) ; Jackson Foundation ; UK Natural Environment Research Council: NE/P001092/1 ; European Research Council Advanced Investigator Award (GEM-TRAIT): 321131 ; NERC: NE/I014705/1 ; NERC: NE/K016369/1 ; NERC: NE/F005776/1 ; NERC: NE/K016385/1 ; NERC: NE/J011002/1 ; CNPq: 457914/2013-0/MCTI/ CNPq/FNDCT/LBA/ESECAFLOR ; CNPq: 403725/ 2012-7 ; CNPq: 441244/2016-5 ; CNPq: 457602/2012-0 ; Project USA-NAS/PEER: PGA-2000005316 ; Project ReFlor FAPEMAT: 0589267/2016 ; CNPq: 574008/2008-0 ; Empresa Brasileira de Pesquisa Agropecuaria - Embrapa: SEG: 02.08.06.005.00 ; European Research Council (H2020-MSCA-RISE-2015): 691053-ODYSSEA ; UK government Darwin Initiative: 17-023 ; UK Natural Environment Research Council (NERC): NE/F01614X/1 ; UK Natural Environment Research Council (NERC): NE/G000816/1 ; UK Natural Environment Research Council (NERC): NE/K016431/1 ; UK Natural Environment Research Council (NERC): NE/P004512/1 ; : PQ-2 ; Meteorological extreme events such as El Nino events are expected to affect tropical forest net primary production (NPP) and woody growth, but there has been no large-scale empirical validation of this expectation. We collected a large high-temporal resolution dataset (for 1-13 years depending upon location) of more than 172 000 stem growth measurements using dendrometer bands from across 14 regions spanning Amazonia, Africa and Borneo in order to test how much month-to-month variation in stand-level woody growth of adult tree stems (NPPstem) can be explained by seasonal variation and interannual meteorological anomalies. A key finding is that woody growth responds differently to meteorological variation between tropical forests with a dry season (where monthly rainfall is less than 100 mm), and aseasonal wet forests lacking a consistent dry season. In seasonal tropical forests, a high degree of variation in woody growth can be predicted from seasonal variation in temperature, vapour pressure deficit, in addition to anomalies of soil water deficit and shortwave radiation. The variation of aseasonal wet forest woody growth is best predicted by the anomalies of vapour pressure deficit, water deficit and shortwave radiation. In total, we predict the total live woody production of the global tropical forest biome to be 2.16 Pg C yr(-1), with an interannual range 1.96-2.26 Pg C yr(-1) between 1996-2016, and with the sharpest declines during the strong El Nino events of 1997/8 and 2015/6. There is high geographical variation in hotspots of El Nino-associated impacts, with weak impacts in Africa, and strongly negative impacts in parts of Southeast Asia and extensive regions across central and eastern Amazonia. Overall, there is high correlation (r = -0.75) between the annual anomaly of tropical forest woody growth and the annual mean of the El Nino 3.4 index, driven mainly by strong correlations with anomalies of soil water deficit, vapour pressure deficit and shortwave radiation. This article is part of the discussion meeting issue 'The impact of the 2015/2016 El Nino on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.