Gavin J. Kenny

The effects of climate variability and change on grape suitability in Europe

Abstract A latitude‐temperature index (LTI) has been used in combination with a winter severity constraint to assess climate suitability of grapes in different regions of Europe. A detailed analysis has been carried out using period mean and individual year data for the 1951–1980 period. This allows for identification of core areas of suitability for each of four broadly defined grape cultivar groupings (cool to hot‐climate grapes). Areas that are at the northern margins of suitability, and that are marginal between different groups are also identified. A much clearer picture of the present distribution of grapes in Europe is given by this approach. The possible effect of climate change on grape suitability has also been evaluated. Output from several general circulation models (GCMs) have been used to adjust the period mean and individual year data and the LTI calculated for these adjusted data. While there is a range of uncertainty, both in relation to the magnitude and timing of climate change, it is e...

Trends and persistence in precipitation in the Ganges, Brahmaputra and Meghna river basins

Abstract The Ganges, Brahmaputra and Meghna (GBM) river basins occupy about 1.75 x 106 km2 of the Himalayan region. More than half a billion people in Nepal, India, Bhutan and Bangladesh are directly or indirectly dependent on the water resources of the GBM rivers. These river basins are characterized by diversified climatic patterns. Analyses of trends and persistence in precipitation over these river basins are necessary for sound water resources planning. Time series of annual precipitation for each of the 16 meteorological subdivisions covering the three river basins were examined for trends using the Mann-Kendall rank statistic, Students t-test and regression analysis, and for persistence using first order autocorrelation analysis. Results indicate that precipitation in the Ganges basin is by-and-large stable. Precipitation in one subdivision in the Brahmaputra bassin shows a decreasing trend and another shows an increasing trend. One of the three subdivisions in the Meghna basin shows a decreasing ...

Are floods getting worse in the Ganges, Brahmaputra and Meghna basins?

The Ganges, Brahmaputra and Meghna/Barak rivers are lifelines for millions of people in South Asia in Nepal, India, Bhutan and Bangladesh. They supply water for food and fibre production and for industrial and domestic purposes. They are also sources of disastrous floods that cause substantial damage to agriculture and infrastructure in these countries. There are claims that flood discharges, areal extent, and damage-costs are getting worse in the Ganges, Brahmaputra and Meghna/Barak basins. The validity of these claims was examined by applying four different statistical tests to the peak discharge time series and flooded areas. The results indicate that no conclusive changes have occurred over the last few decades. Reports of increased flood damage may be due to a combination of other factors, such as improved damage assessment techniques, and the expansion and intensification of settlement in flood-prone areas, but this was not tested in this paper and should be top priority for future research.

Integrated Model Systems for National Assessments of the Effects of Climate Change: Applications in New Zealand and Bangladesh

To examine the sensitivity of environmental systems to climatic variability and change, integrated model systems for climate impact assessment are being developed for New Zealand (CLIMPACTS) and Bangladesh (BDCLIM). Features common to both model systems include a global climate model, regional modules for generating climate scenarios, and models for biophysical impact analyses. For CLIMPACTS, modified ecosystem models for horticultural crops, arable crops, and pasture production are being incorporated. For BDCLIM, the emphasis is on analysis of possible changes in agroclimatic zones and hydrology, including the risks of floods and droughts. The initial emphasis of both systems is on nationwide spatial analyses, using simplified models as much as possible. The development of integrated model systems supports the needs of the respective countries in assessing scientific uncertainties, evaluating vulnerabilities, and identifying adaptation options as a basis for international reporting requirements under the U.N. Framework Convention on Climate Change and for policy and planning at national and regional levels. The major advantage of such integrated model systems is that they can readily be updated as the science of climate change advances, thus providing an evolving tool for future reassessments of climate impacts.

Climate variations and New Zealand agriculture: The CLIMPACTS system and issues of spatial and temporal scale

Internationally and nationally, New Zealand has a growing requirement to assess and report on the possible effects of climate change. In association with this requirement, the science of climate change is rapidly evolving requiring a capacity for rapid reassessment of effects to take account of scientific advances. Consequently, past assessment methods, which have not been computationally efficient, nor easily repeated, are becoming outdated. To address this gap, an integrated assessment model (IAM), the CLIMPACTS system, has been developed for New Zealand. The CLIMPACTS system has been developed to provide flexibility in application, to be easily updated to take account of scientific advances, and capable of providing information in a manner that is relevant to policymakers. In order to be relevant in New Zealand, it has been necessary to account for different scales of assessment, nationally, at specific sites, and regionally. Nationally, the focus is on spatial applications (e.g., changes in areas of suitability), whereas at sites, the focus is on temporal applications (e.g., changes in risk). The regional capacity in the CLIMPACTS system has required an integration of spatial and temporal applications. This paper describes briefly the capability that has been developed at these different scales of assessment, with brief examples for each. The CLIMPACTS system has enhanced New Zealands capability to examine environmental sensitivities to climate change, as a basis for better informed policy decisions. Importantly, it is an evolving platform that can be readily extended to other sectors and updated, for example, to account for the effects of internationally agreed greenhouse gas (GHG) emission targets.

Are we Doing Relevant Research on Climate Change? Reflections from a Review of " Climate Variability, Climate Change and Wine Production in the Western US"

With a few exceptions wine grape production is confined to a well defined climatic range in the mid-latitudes. Within this range there is a mix of centuries old tradition, principally confined to Europe, and modern production techniques. Climate change will challenge both traditional and modern production systems, particularly in terms of their ability to adapt over time. This has been confirmed by the many climate change impact studies that have been completed on wine grapes. These studies have now spanned nearly 20 years and have collectively provided a comprehensive picture of what climate change might mean for wine grape production. Within the 20-year timeframe of studies on climate change and wine grapes, there has also been a significant evolution in climate change research. The two predominant research streams have been impacts and adaptation, and mitigation. The focus of this review is the former. Early impacts research followed a fairly prescribed step-by-stepmethodology, using data from available climate change scenarios to simulate changes using crop models. This methodology is still in use. However, from the midto late 1990s there was a shift towards vulnerability assessments, which extended the narrow bounds of modelling to considering the wider human dimensions of climate change. Over the last decade there has been a further evolution, towards consideration of the sustainability context for climate change responses and increasingly a focus on resilience assessments. This preamble is a necessary introduction to a review of a recent article on climate variability, climate change and wine production in the Western US. This article has been published as a chapter in a publication on ‘Climate Warming in Western North America’. As stated in the Preface “this book presents evidence on the scientific aspects for policy makers who need facts on the issue in order to formulate their course of action”. On the whole this book is a collection of relevant scientific papers, rather than a comprehensive regional study. The article on wine grapes provides some useful insights into effects of the El Niño–Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). Additionally, it provides a climate change analysis using output from a regional climate model. The methodology is sound and the results undoubtedly add some value to previous studies by the researchers. However, the key conclusions don’t really add to what is already known about the potential effects of climate change in this region. Importantly, as an article for policy-makers, it is too narrowly focused on new work that is of incremental benefit. Having read the book’s