scholarly journals Globally observed trends in mean and extreme river flow attributed to climate change

Science ◽  
2021 ◽  
Vol 371 (6534) ◽  
pp. 1159-1162 ◽  
Author(s):  
Lukas Gudmundsson ◽  
Julien Boulange ◽  
Hong X. Do ◽  
Simon N. Gosling ◽  
Manolis G. Grillakis ◽  
...  
Keyword(s):  
Climate Change ◽  
Radiative Forcing ◽  
River Flow ◽  
State Of The Art ◽  
Global Scale ◽  
Anthropogenic Climate Change ◽  
Recent Trends ◽  
High Flows ◽  
Analyze Time Series

Anthropogenic climate change is expected to affect global river flow. Here, we analyze time series of low, mean, and high river flows from 7250 observatories around the world covering the years 1971 to 2010. We identify spatially complex trend patterns, where some regions are drying and others are wetting consistently across low, mean, and high flows. Trends computed from state-of-the-art model simulations are consistent with the observations only if radiative forcing that accounts for anthropogenic climate change is considered. Simulated effects of water and land management do not suffice to reproduce the observed trend pattern. Thus, the analysis provides clear evidence for the role of externally forced climate change as a causal driver of recent trends in mean and extreme river flow at the global scale.

scholarly journals Anthropogenic climate change has changed frequency of past flood during 2010-2013

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yukiko Hirabayashi ◽  
Haireti Alifu ◽  
Dai Yamazaki ◽  
Yukiko Imada ◽  
Hideo Shiogama ◽  
...  
Keyword(s):  
Climate Change ◽  
South America ◽  
Radiative Forcing ◽  
Water Cycle ◽  
Flood Frequency ◽  
Anthropogenic Climate Change ◽  
Climate Change Signal ◽  
Northern Eurasia ◽  
Large Ensemble ◽  
The Impact

AbstractThe ongoing increases in anthropogenic radiative forcing have changed the global water cycle and are expected to lead to more intense precipitation extremes and associated floods. However, given the limitations of observations and model simulations, evidence of the impact of anthropogenic climate change on past extreme river discharge is scarce. Here, a large ensemble numerical simulation revealed that 64% (14 of 22 events) of floods analyzed during 2010-2013 were affected by anthropogenic climate change. Four flood events in Asia, Europe, and South America were enhanced within the 90% likelihood range. Of eight snow-induced floods analyzed, three were enhanced and four events were suppressed, indicating that the effects of climate change are more likely to be seen in the snow-induced floods. A global-scale analysis of flood frequency revealed that anthropogenic climate change enhanced the occurrence of floods during 2010-2013 in wide area of northern Eurasia, part of northwestern India, and central Africa, while suppressing the occurrence of floods in part of northeastern Eurasia, southern Africa, central to eastern North America and South America. Since the changes in the occurrence of flooding are the results of several hydrological processes, such as snow melt and changes in seasonal and extreme precipitation, and because a climate change signal is often not detectable from limited observation records, large ensemble discharge simulation provides insights into anthropogenic effects on past fluvial floods.

Evidence of river flow regulation loss over time in the Magdalena river basin 

2021 ◽  
Author(s):  
Diver E. Marín ◽  
Juan F. Salazar ◽  
José A. Posada-Marín
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
River Basin ◽  
River Flow ◽  
Southern Oscillation ◽  
Scaling Theory ◽  
Scaling Properties ◽  
Low Flows ◽  
High Flows ◽  
Magdalena River

<p>Some of the main problems in hydrological sciences are related to how and why river flows change as a result of environmental change, and what are the corresponding implications for society. This has been described as the Panta Rhei context, which refers to the challenge of understanding and quantifying hydrological dynamics in a changing environment, i.e. under the influence of non-stationary effects. The river flow regime in a basin is the result of a complex aggregation process that has been studied by the scaling theory, which allows river basins to be classified as regulated or unregulated and to identify a critical threshold between these states. Regulation is defined here as the basin’s capacity to either dampen high flows or to enhance low flows. This capacity depends on how basins store and release water through time, which in turn depends on many processes that are highly dynamic and sensitive to environmental change. Here we focus on the Magdalena river basin in northwestern South America, which is the main basin for water and energy security in Colombia, and at the same time, it has been identified as one of the most vulnerable regions to be affected by climate change. Building upon some of our previous studies, here we use data analysis to study the evolution of regulation in the Magdalena basin for 1992-2015 based on the scaling theory for extreme flows. In contrast to most previous studies, here we focus on the scaling properties of events rather than on long term averages. We discuss possible relations between changes in the scaling properties and environmental factors such as climate variability, climate change, and land use/land cover change, as well as the potential implications for water security in the country. Our results show that, during the last few decades, the Magdalena river basin has maintained its capacity to regulate low flows (i.e. amplification) whereas it has been losing its capacity to regulate high flows (i.e. dampening), which could be associated with the occurrence of the extremes phases of  El Niño Southern Oscillation (ENSO) and anthropogenic effects, mainly deforestation. These results provide foundations for using the scaling laws as empirical tools for understanding temporal changes of hydrological regulation and simultaneously generate useful scientific evidence that allows stakeholders to take decisions related to water management in the Magdalena river basin in the context of environmental change.</p>

scholarly journals Is It Time for a Reset in Arctic Governance?

2019 ◽  
Vol 11 (16) ◽  
pp. 4497 ◽  
Author(s):  
Oran R. Young
Keyword(s):  
Climate Change ◽  
The United States ◽  
Global Scale ◽  
Peripheral Region ◽  
Great Power ◽  
The Arctic ◽  
Arctic Council ◽  
Ground Zero ◽  
Regime Complex

Conditions in the Arctic today differ from those prevailing during the 1990s in ways that have far-reaching implications for the architecture of Arctic governance. What was once a peripheral region regarded as a zone of peace has turned into ground zero for climate change on a global scale and a scene of geopolitical maneuvering in which Russia is flexing its muscles as a resurgent great power, China is launching economic initiatives, and the United States is reacting defensively as an embattled but still potent hegemon. This article explores the consequences of these developments for Arctic governance and specifically for the role of the Arctic Council. The article canvasses options for adjusting the council’s membership and its substantive remit. It pays particular attention to opportunities for the council to play a role in managing the increasingly complex Arctic regime complex.

Global Climate Change by Wetland Greenhouse Gas Fluxes

2022 ◽  
pp. 182-196
Author(s):  
Madhavi Konni ◽  
Vara Saritha ◽  
Pulavarthi Madhuri ◽  
K. Soma Sekhar ◽  
Manoj Kumar Karnena
Keyword(s):  
Climate Change ◽  
Environmental Management ◽  
Global Climate Change ◽  
Radiative Forcing ◽  
Global Climate ◽  
Radiative Balance ◽  
Gas Fluxes ◽  
Greenhouse Gas Fluxes ◽  
Ghg Fluxes

Wetlands (WLs) in the landscapes are important for the GHGs production, ingesting, and exchange with the atmosphere. In this chapter, the authors illustrated how the WLs influence climate change, even though it is typical for determining the climatic role of WLs in the broader perspective. The conclusions might be wary based on the radiative balance as the radiative forcing since the 1750s or climatic roles are continuously changing in the wetlands. Degradation of WLs leads to reducing their functioning, and GHG fluxes might change and alter the climatic roles of the WLs. The chapter demonstrated that WL disturbances might cause global warming for a longer duration even though the WLs are restored or managed by replacing them with the mitigation WLs. Thus, activities that cause disturbance in the WLs leading to carbon oxidation in the soils should be avoided. Regulating the climate is an ecosystem service in the WLs; during the planning of the WLs, protection, restoration, and creation, environmental management should be considered.

scholarly journals Anthropogenic climate change is worsening North American pollen seasons

2021 ◽  
Vol 118 (7) ◽  
pp. e2013284118
Author(s):  
William R. L. Anderegg ◽  
John T. Abatzoglou ◽  
Leander D. L. Anderegg ◽  
Leonard Bielory ◽  
Patrick L. Kinney ◽  
...  
Keyword(s):  
Climate Change ◽  
North American ◽  
Airborne Pollen ◽  
Respiratory Health ◽  
Field Studies ◽  
Anthropogenic Climate Change ◽  
Detection And Attribution ◽  
Pollen Concentrations ◽  
Pollen Seasons

Airborne pollen has major respiratory health impacts and anthropogenic climate change may increase pollen concentrations and extend pollen seasons. While greenhouse and field studies indicate that pollen concentrations are correlated with temperature, a formal detection and attribution of the role of anthropogenic climate change in continental pollen seasons is urgently needed. Here, we use long-term pollen data from 60 North American stations from 1990 to 2018, spanning 821 site-years of data, and Earth system model simulations to quantify the role of human-caused climate change in continental patterns in pollen concentrations. We find widespread advances and lengthening of pollen seasons (+20 d) and increases in pollen concentrations (+21%) across North America, which are strongly coupled to observed warming. Human forcing of the climate system contributed ∼50% (interquartile range: 19–84%) of the trend in pollen seasons and ∼8% (4–14%) of the trend in pollen concentrations. Our results reveal that anthropogenic climate change has already exacerbated pollen seasons in the past three decades with attendant deleterious effects on respiratory health.

scholarly journals Not all biodiversity rich spots are climate refugia

2021 ◽  
Vol 18 (24) ◽  
pp. 6567-6578
Author(s):  
Ádám T. Kocsis ◽  
Qianshuo Zhao ◽  
Mark J. Costello ◽  
Wolfgang Kiessling
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Global Scale ◽  
Absolute Temperature ◽  
Elevated Risk ◽  
Anthropogenic Climate Change ◽  
Range Shifts ◽  
Future Warming ◽  
Almost All

Abstract. Anthropogenic climate change is increasingly threatening biodiversity on a global scale. Rich spots of biodiversity, regions with exceptionally high endemism and/or number of species, are a top priority for nature conservation. Terrestrial studies have hypothesized that rich spots occur in places where long-term climate change was dampened relative to other regions. Here we tested whether biodiversity rich spots are likely to provide refugia for organisms during anthropogenic climate change. We assessed the spatial distribution of both historic (absolute temperature change and climate change velocities) and projected climate change in terrestrial, freshwater, and marine rich spots. Our analyses confirm the general consensus that global warming will impact almost all rich spots of all three realms and suggest that their characteristic biota is expected to witness similar forcing to other areas, including range shifts and elevated risk of extinction. Marine rich spots seem to be particularly sensitive to global warming: they have warmed more, have higher climate velocities, and are projected to experience higher future warming than non-rich-spot areas. However, our results also suggest that terrestrial and freshwater rich spots will be somewhat less affected than other areas. These findings emphasize the urgency of protecting a comprehensive and representative network of biodiversity-rich areas that accommodate species range shifts under climate change.

scholarly journals Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

2014 ◽  
Vol 14 (23) ◽  
pp. 32709-32933 ◽  
Author(s):  
P. S. Monks ◽  
A. T. Archibald ◽  
A. Colette ◽  
O. Cooper ◽  
M. Coyle ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Quality ◽  
Tropospheric Ozone ◽  
Ecosystem Health ◽  
Climate Change Mitigation ◽  
Global Scale ◽  
Background Ozone ◽  
Oxidation Chemistry ◽  
Change Mitigation

Abstract. Ozone holds a certain fascination in atmospheric science. It is ubiquitous in the atmosphere, central to tropospheric oxidation chemistry, yet harmful to human and ecosystem health as well as being an important greenhouse gas. It is not emitted into the atmosphere but is a by-product of the very oxidation chemistry it largely initiates. Much effort is focussed on the reduction of surface levels of ozone owing to its health impacts but recent efforts to achieve reductions in exposure at a country scale have proved difficult to achieve due to increases in background ozone at the zonal hemispheric scale. There is also a growing realisation that the role of ozone as a short-lived climate pollutant could be important in integrated air quality climate-change mitigation. This review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models. It takes the view that knowledge across the scales is important for dealing with air quality and climate change in a synergistic manner.

scholarly journals The Record Low Bering Sea Ice Extent in 2018: Context, Impacts, and an Assessment of the Role of Anthropogenic Climate Change

2020 ◽  
Vol 101 (1) ◽  
pp. S53-S58 ◽  
Author(s):  
Richard L. Thoman ◽  
Uma S. Bhatt ◽  
Peter A. Bieniek ◽  
Brian R. Brettschneider ◽  
Michael Brubaker ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Bering Sea ◽  
Anthropogenic Climate Change ◽  
Sea Ice Extent

scholarly journals Introduction: European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) – integrating aerosol research from nano to global scales

2008 ◽  
Vol 8 (6) ◽  
pp. 19415-19455 ◽  
Author(s):  
M. Kulmala ◽  
A. Asmi ◽  
H. K. Lappalainen ◽  
K. S. Carslaw ◽  
U. Pöschl ◽  
...  
Keyword(s):  
Air Quality ◽  
State Of The Art ◽  
Global Scale ◽  
Research Groups ◽  
Global Models ◽  
Aerosol Cloud ◽  
Operational Systems ◽  
First Results ◽  
Integrated Project

Abstract. The European Aerosol Cloud Climate and Air Quality Interactions project EUCAARI is an EU Research Framework 6 integrated project focusing on understanding the interactions of climate and air pollution. EUCAARI works in an integrative and multidisciplinary way from nano- to global scale. EUCAARI brings together several leading European research groups, state-of-the-art infrastructure and some key scientists from third countries to investigate the role of aerosol on climate and air quality. Altogether 48 partners from 25 countries are participating in EUCAARI. During the first 16 months EUCAARI has built operational systems e.g. established pan-European measurement network for Lagrangian studies and four stations in developing countries. Also an improved understanding of nanoscale processes (like nucleation) has been implemented in global models. Here we present the research methods, organisation, operations and first results of EUCAARI.

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