Impacts of climate change on extreme precipitation and dry spells in New Zealand

2020 ◽  
Author(s):  
Ludovico Nicotina ◽  
Francesco Comola ◽  
Saket Satyam ◽  
Carlotta Scudeler ◽  
Mani Prakash
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Extreme Precipitation ◽  
Southern Oscillation ◽  
Asia Pacific ◽  
Climate Change Scenarios ◽  
The North ◽  
Dry Spells ◽  
Enso Phases

<p>Global warming is expected to enhance El Niño Southern Oscillation (ENSO), with potential impacts on frequency and severity of floods and droughts in numerous countries of the Asia-Pacific region. However, the limited time coverage of historical records and the large uncertainties underlying climate model projections impair our ability to identify trends in extreme rainfall and dry spells. Here, we generate and analyze a long-term stochastic precipitation dataset for New Zealand that accounts for the potential effects of climate change. For this purpose, we draw on a 60 year-dataset of daily precipitation maps to identify the rainfall principal components and quantify their temporal correlations with the ENSO signal. We then generate a long-term stochastic set of daily rainfall maps correlated with ENSO projections, corresponding to different climate change scenarios. Our results indicate that climate change may lead to more intense precipitation in the Southern Alps during positive ENSO phases. Conversely, extreme precipitation is likely to increase in the North Island during negative ENSO phases. Our analyses also suggest that the duration of extreme dry spells may significantly increase along the east side of the North and South Islands during positive ENSO phases. These results may guide the implementation of effective adaptation and mitigation strategies against the increasing risk of natural catastrophes.</p>

Impacts of El Niño Southern Oscillation on flood risk and insured losses in New Zealand

2021 ◽  
Author(s):  
Francesco Comola ◽  
Carlotta Scudeler ◽  
Saket Satyam ◽  
Ludovico Nicotina
Keyword(s):  
Time Series ◽  
New Zealand ◽  
Flood Risk ◽  
Southern Oscillation ◽  
Asia Pacific ◽  
Economic Losses ◽  
Flood Events ◽  
Enso Events ◽  
Insured Losses ◽  
Enso Phases

<p>Global warming is expected to enhance El Niño Southern Oscillation (ENSO) with potential impacts on rainfall and flood risk in numerous countries of the Asia-Pacific region. Modeling studies have suggested that positive and negative ENSO phases may intensify by as much as 25% under extreme climate projections. However, the influence of ENSO variability on flood risk in Asia-Pacific countries is still largely unexplored. Here, we aim to shed light into the link between ENSO, flood risk, and insured losses in New Zealand by combining rainfall observations and state-of-the-art flood risk models. We draw on 60 years of daily precipitation measurements to quantify the statistical correlations between the rainfall principal components and the ENSO historical time series. This allows us to generate 50,000 years of stochastic daily rainfall maps correlated with a long-term, synthetic ENSO time series. The stochastic precipitation maps are then used to drive streamflow and flood simulations at 20 m spatial resolution. Our results indicate that positive and negative ENSO phases increase the flood risk in different regions of New Zealand, and that extreme ENSO events tend to cause more severe flood events. We finally investigate the potential differences in economic losses during positive and negative ENSO phases by combining modeled flood footprints with exposure and vulnerability data. These results may guide the implementation of effective adaptation and mitigation strategies against the increasing risk of flood events in warming climate.</p>

scholarly journals Why this time is different: The North Korea Crisis and New Zealand’s interests.

2020 ◽  
Author(s):  
Reuben Steff
Keyword(s):  
New Zealand ◽  
Korean Peninsula ◽  
North Korea ◽  
Structural Changes ◽  
Positive Outcome ◽  
Asia Pacific ◽  
The North ◽  
Shifting Balance ◽  
The Cold War

North Korea remains the ultimate international outlier: an isolated totalitarian state seeking to acquire a credible nuclear weapons program. As such, a simmering crisis between the North and the US has been playing out since the end of the Cold War. Yet, while past attempts at diplomacy have failed, change is afoot as the Trump administration seeks to shift US-North Korean relations onto a new footing. While skepticism is warranted, this article explains that new personalities and a shift in the structure of power in and around the Korean peninsula provide grounds for cautious optimism that long-term rapprochement is feasible. Small states like New Zealand have a stake in a positive outcome, as its interests dictate that it seeks a stable and secure Asia-Pacific. Furthermore, US-North Korean negotiations take place against the backdrop of intensifying US-China great power competition; a situation that complicates the picture and suggests that long-term peace on the peninsula is only possible if diplomacy takes into account all regional actors. With the above in mind, this article makes a contribution to our understanding of the North Korean issue. It provides a background to the crisis; outlines how personal and structural changes (in terms of the shifting balance of power) suggest that the outcome of diplomatic efforts could be different to failures of the past; considers whether North Korea is an ‘irrational’ actor; and offers a conceptual (and self-avowedly idealistic) framework – ‘strategic liberalism’ – to act as a guide for New Zealand as it looks to calibrate its approach to ongoing tensions and diplomacy on the Korean peninsula.

scholarly journals Effect of climate change on Oriental fruit fly in New Zealand and the Pacific

2007 ◽  
Vol 60 ◽  
pp. 271-278 ◽  
Author(s):  
D.J. Kriticos ◽  
A.E.A. Stephens ◽  
A. Leriche
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Potential Distribution ◽  
Fruit Fly ◽  
Climate Change Scenarios ◽  
Oriental Fruit Fly ◽  
Central Pacific ◽  
The North ◽  
The Pacific ◽  
Successful Establishment

A CLIMEX model of the Oriental fruit fly (OFF) indicates that under the reference climate (19611990) OFF could persist throughout most of the central Pacific In New Zealand it could establish throughout much of the lowlying areas of the North Island and much of New Zealand could support shortterm populations during the summer months Climate change scenarios for the 2080s indicate that in the central Pacific the change in potential distribution is relatively minor However parts of New Zealand could become substantially more climatically suitable increasing the likelihood of successful establishment of OFF after an incursion and seriously threatening the horticultural sector Should OFF become established in New Zealand it is likely to follow any expansion of the horticultural sector into the coastal areas of the eastern part of the South Island as far south as Oamaru

scholarly journals Possible Effects of Climate Change on New Zealand Design Wind Speeds

2020 ◽  
Author(s):  
Amir Ali Safaei Pirooz ◽  
Richard G.J. Flay ◽  
Richard Turner ◽  
Cesar Azorin-Molina
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Wind Speed ◽  
Extreme Weather Events ◽  
Wind Gust ◽  
Climate Change Scenarios ◽  
Wind Speeds ◽  
Weather Events ◽  
Safety And Reliability

<p>The climate is changing, and as a result, the Earth could experience more severe extreme weather events. Growing interest and concern about the effects of climate change on cities, infrastructures and people’s lives raises the question “how are design wind speeds influenced by different climate change scenarios?”. This study aims at (i) analysing the gust wind records of four meteorological stations across New Zealand for the period 1972-2017; (ii) investigating whether or not the long-term wind gust series have changed significantly; and (iii) how these changes can be considered in the estimation of design wind speeds to ensure the safety and reliability of the future structures.</p><p>Historical hourly and daily gust wind speed series recorded at the four selected stations were subjected to a robust quality control and homogenisation protocol to ensure all the artificial inhomogeneities resulting from factors like station relocations, anemometer height changes, instrumentation malfunctions, instrumentation changes, different sampling intervals, and observation environment changes, have been eliminated prior to any subsequent analyses. Then, annual and seasonal trends in both magnitudes and frequencies of the extreme winds were evaluated as to whether the observed trends are statistically significant or not by calculating p-values. From the derived gust trends, some recommendations are proposed for consideration in regard to revising the design wind speeds for calculating the wind loads on structures. In addition, the findings of the study are compared with gust wind speed trends in several other countries and also with IPCC 5<sup>th</sup> assessment projections for New Zealand [1].</p><p>The main findings of this research are summarised as follows:</p><ul><li>The magnitude and frequency of wind gust showed negative (significant for some stations and seasons) trends.</li> <li>This result suggests that at this stage no extra multiplier is required to be applied to the New Zealand design wind speeds.</li> <li>Additional analyses of the long-term wind gust trends at more stations across New Zealand are needed.</li> </ul><p> </p><p><strong>Reference</strong></p><p>[1] Ministry for the Environment 2018. Climate Change Projections for New Zealand: Atmosphere Projections Based on Simulations from the IPCC Fifth Assessment, 2nd Edition. Wellington: Ministry for the Environment.</p>

scholarly journals Assessing the long-term effectiveness of Nature-Based Solutions under different climate change scenarios

2021 ◽  
pp. 148515
Author(s):  
Eulalia Gómez Martín ◽  
María Máñez Costa ◽  
Sabine Egerer ◽  
Uwe Schneider
Keyword(s):  
Climate Change ◽  
Climate Change Scenarios

scholarly journals Vulnerability of the North Water ecosystem to climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sofia Ribeiro ◽  
Audrey Limoges ◽  
Guillaume Massé ◽  
Kasper L. Johansen ◽  
William Colgan ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Late Holocene ◽  
Sediment Cores ◽  
Arctic Ecosystems ◽  
Little Auk ◽  
The North ◽  
Water Ecosystem ◽  
North Water

AbstractHigh Arctic ecosystems and Indigenous livelihoods are tightly linked and exposed to climate change, yet assessing their sensitivity requires a long-term perspective. Here, we assess the vulnerability of the North Water polynya, a unique seaice ecosystem that sustains the world’s northernmost Inuit communities and several keystone Arctic species. We reconstruct mid-to-late Holocene changes in sea ice, marine primary production, and little auk colony dynamics through multi-proxy analysis of marine and lake sediment cores. Our results suggest a productive ecosystem by 4400–4200 cal yrs b2k coincident with the arrival of the first humans in Greenland. Climate forcing during the late Holocene, leading to periods of polynya instability and marine productivity decline, is strikingly coeval with the human abandonment of Greenland from c. 2200–1200 cal yrs b2k. Our long-term perspective highlights the future decline of the North Water ecosystem, due to climate warming and changing sea-ice conditions, as an important climate change risk.

scholarly journals Climate Change Influences Basidiome Emergence of Leaf-Cutting Ant Cultivars

2021 ◽  
Vol 7 (11) ◽  
pp. 912
Author(s):  
Rodolfo Bizarria ◽  
Pepijn W. Kooij ◽  
Andre Rodrigues
Keyword(s):  
Climate Change ◽  
Climate Change Scenarios ◽  
Nest Architecture ◽  
Historical Records ◽  
Climate Data ◽  
Temperature And Precipitation ◽  
Data Analyses ◽  
Symbiotic Mutualism ◽  
Leaf Cutting

Maintaining symbiosis homeostasis is essential for mutualistic partners. Leaf-cutting ants evolved a long-term symbiotic mutualism with fungal cultivars for nourishment while using vertical asexual transmission across generations. Despite the ants’ efforts to suppress fungal sexual reproduction, scattered occurrences of cultivar basidiomes have been reported. Here, we review the literature for basidiome occurrences and associated climate data. We hypothesized that more basidiome events could be expected in scenarios with an increase in temperature and precipitation. Our field observations and climate data analyses indeed suggest that Acromyrmex coronatus colonies are prone to basidiome occurrences in warmer and wetter seasons. Even though our study partly depended on historical records, occurrences have increased, correlating with climate change. A nest architecture with low (or even the lack of) insulation might be the cause of this phenomenon. The nature of basidiome occurrences in the A. coronatus–fungus mutualism can be useful to elucidate how resilient mutualistic symbioses are in light of climate change scenarios.

scholarly journals Impact of climate change on hydro-meteorological drought over the Be River Basin, Viet Nam

2021 ◽  
Author(s):  
Dao Nguyen Khoi ◽  
Truong Thao Sam ◽  
Pham Thi Loi ◽  
Bui Viet Hung ◽  
Van Thinh Nguyen
Keyword(s):  
Climate Change ◽  
River Basin ◽  
General Circulation ◽  
Southern Oscillation ◽  
Meteorological Drought ◽  
Climate Projections ◽  
Research Station ◽  
Climate Change Scenarios ◽  
Study Region ◽  
Meteorological Droughts

Abstract In this paper, the responses of hydro-meteorological drought to changing climate in the Be River Basin located in Southern Vietnam are investigated. Climate change scenarios for the study area were statistically downscaled using the Long Ashton Research Station Weather Generator tool, which incorporates climate projections from Coupled Model Intercomparison Project 5 (CMIP5) based on an ensemble of five general circulation models (Can-ESM2, CNRM-CM5, HadGEM2-AO, IPSL-CM5A-LR, and MPI-ESM-MR) under two Representative Concentration Pathway (RCP) scenarios (RCP4.5 and RCP8.5). The Soil and Water Assessment Tool model was employed to simulate streamflow for the baseline time period and three consecutive future 20 year periods of 2030s (2021–2040), 2050s (2041–2060), and 2070s (2061–2080). Based on the simulation results, the Standardized Precipitation Index and Standardized Discharge Index were estimated to evaluate the features of hydro-meteorological droughts. The hydrological drought has 1-month lag time from the meteorological drought and the hydro-meteorological droughts have negative correlations with the El Niño Southern Oscillation and Pacific Decadal Oscillation. Under the climate changing impacts, the trends of drought severity will decrease in the future; while the trends of drought frequency will increase in the near future period (2030s), but decrease in the following future periods (2050 and 2070s). The findings of this study can provide useful information to the policy and decisionmakers for a better future planning and management of water resources in the study region.

scholarly journals Soil salinization under different climate change scenarios: A global scale analysis

2021 ◽  
Author(s):  
Nima Shokri ◽  
Amirhossein Hassani ◽  
Adisa Azapagic
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Soil Salinity ◽  
Global Scale ◽  
Soil Salinization ◽  
Water Evaporation ◽  
Climate Change Scenarios ◽  
Spatio Temporal ◽  
Salt Affected Soils

<p>Population growth and climate change is projected to increase the pressure on land and water resources, especially in arid and semi-arid regions. This pressure is expected to affect all driving mechanisms of soil salinization comprising alteration in soil hydrological balance, sea salt intrusion, wet/dry deposition of wind-born saline aerosols — leading to an increase in soil salinity. Soil salinity influences soil stability, bio-diversity, ecosystem functioning and soil water evaporation (1). It can be a long-term threat to agricultural activities and food security. To devise sustainable action plan investments and policy interventions, it is crucial to know when and where salt-affected soils occur. However, current estimates on spatio-temporal variability of salt-affected soils are majorly localized and future projections in response to climate change are rare. Using Machine Learning (ML) algorithms, we related the available measured soil salinity values (represented by electrical conductivity of the saturated paste soil extract, EC<sub>e</sub>) to some environmental information (or predictors including outputs of Global Circulation Models, soil, crop, topographic, climatic, vegetative, and landscape properties of the sampling locations) to develop a set of data-driven predictive tools to enable the spatio-temporal predictions of soil salinity. The outputs of these tools helped us to estimate the extent and severity of the soil salinity under current and future climatic patterns at different geographical levels and identify the salinization hotspots by the end of the 21<sup>st</sup> century in response to climate change. Our analysis suggests that a soil area of 11.73 Mkm<sup>2</sup> located in non-frigid zones has been salt-affected in at least three-fourths of the 1980 - 2018 period (2). At the country level, Brazil, Peru, Sudan, Colombia, and Namibia were estimated to have the highest rates of annual increase in the total area of soils with an EC<sub>e</sub> ≥ 4 dS m<sup>-1</sup>. Additionally, the results indicate that by the end of the 21<sup>st</sup> century, drylands of South America, southern and Western Australia, Mexico, southwest United States, and South Africa will be the salinization hotspots (compared to the 1961 - 1990 period). The results of this study could inform decision-making and contribute to attaining the United Nation’s Sustainable Development Goals for land and water resources management.</p><p>1. Shokri-Kuehni, S.M.S., Raaijmakers, B., Kurz, T., Or, D., Helmig, R., Shokri, N. (2020). Water Table Depth and Soil Salinization: From Pore-Scale Processes to Field-Scale Responses. Water Resour. Res., 56, e2019WR026707. https://doi.org/ 10.1029/2019WR026707</p><p>2. Hassani, A., Azapagic, A., Shokri, N. (2020). Predicting Long-term Dynamics of Soil Salinity and Sodicity on a Global Scale, Proc. Nat. Acad. Sci., 117, 52, 33017–33027. https://doi.org/10.1073/pnas.2013771117</p>

scholarly journals Climate change impacts the protective effect of forests: A case study in Switzerland

2021 ◽  
Author(s):  
Christine Moos ◽  
Antoine Guisan ◽  
Christophe F. Randin ◽  
Heike Lischke
Keyword(s):  
Climate Change ◽  
Protective Effect ◽  
Climate Warming ◽  
Swiss Alps ◽  
Present Species ◽  
Future Research ◽  
Change Scenario ◽  
Climate Change Scenarios ◽  
Ground Truth Data

Abstract In steep terrain, forests play an important role as natural means of protection against natural hazards, such as rockfall. Due to climate warming, significant changes in the protection service of these forests have to be expected in future. Shifts of current to more drought adapted species may result in temporary or even irreversible losses in the risk reduction provided by these forests. In this study, we assessed how the protective effect against rockfall of a protection forest in the western part of the Valais in the Swiss Alps may change in future, by combining dynamic forest modelling with a quantitative risk analysis. Current and future forest development was modelled with the spatially explicit forest model TreeMig for a moderate (RCP4.5) and an extreme (RCP8.5) climate change scenario. The simulated forest scenarios were compared to ground-truth data from the current forest complex. We quantified the protective effect of the different forest scenarios based on the reduction of rockfall risk for people and infrastructure at the bottom of the slope. Rockfall risk was calculated on the basis of three-dimensional rockfall simulations. The forest simulations predicted a clear decrease in basal area of most of the currently present species in future. The forest turned into a Q. pubescens dominated forest, for both climate scenarios, and mixed with P. sylvestris in RCP4.5. F. sylvatica completely disappeared in RCP8.5. With climate warming, a clear increase in risk is expected for both climate change scenarios. In the long-term (> 100 years), a stabilization of risk, or even a slight decline may be expected due to an increase in biomass of the trees. The results of this study further indicate that regular forest interventions may promote regeneration and thus accelerate the shift in species distribution. Future research should address the long-term effect of different forest management strategies on the protection service of forests under climate change.

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