Michael A. Taylor

Global observed changes in daily climate extremes of temperature and precipitation

A suite of climate change indices derived from daily temperature and precipitation data, with a primary focus on extreme events, were computed and analyzed. By setting an exact formula for each index and using specially designed software, analyses done in different countries have been combined seamlessly. This has enabled the presentation of the most up-to-date and comprehensive global picture of trends in extreme temperature and precipitation indices using results from a number of workshops held in data-sparse regions and high-quality station data supplied by numerous scientists world wide. Seasonal and annual indices for the period 1951-2003 were gridded. Trends in the gridded fields were computed and tested for statistical significance. Results showed widespread significant changes in temperature extremes associated with warming, especially for those indices derived from daily minimum temperature. Over 70% of the global land area sampled showed a significant decrease in the annual occurrence of cold nights and a significant increase in the annual occurrence of warm nights. Some regions experienced a more than doubling of these indices. This implies a positive shift in the distribution of daily minimum temperature throughout the globe. Daily maximum temperature indices showed similar changes but with smaller magnitudes. Precipitation changes showed a widespread and significant increase, but the changes are much less spatially coherent compared with temperature change. Probability distributions of indices derived from approximately 200 temperature and 600 precipitation stations, with near-complete data for 1901-2003 and covering a very large region of the Northern Hemisphere midlatitudes (and parts of Australia for precipitation) were analyzed for the periods 1901-1950, 1951-1978 and 1979-2003. Results indicate a significant warming throughout the 20th century. Differences in temperature indices distributions are particularly pronounced between the most recent two periods and for those indices related to minimum temperature. An analysis of those indices for which seasonal time series are available shows that these changes occur for all seasons although they are generally least pronounced for September to November. Precipitation indices show a tendency toward wetter conditions throughout the 20th century.

A review of observed and projected changes in climate for the islands in the Caribbean

Resumen Los cambios climaticos observados y proyectados tienen implicaciones socioeconomicas importantes para las islas del Caribe. El objetivo de este articulo es presentar informacion esencial sobre el cambio climatico —basada en estudios previos, observaciones disponibles y simulaciones de modelos climaticos— a escalas espaciales relevantes para las islas caribenas. Se utilizan datos del modelo general de circulacion (GCM) incluidos en el Proyecto de Comparacion de Modelos Acoplados fase 3 (CMIP3), asi como del modelo climatico regional (RCM) del Centro Hadley del Reino Unido, para aportar tanto informacion actual como informacion basada en proyecciones sobre precipitaciones y temperatura en estados insulares especifcos. Se utilizan observaciones reticuladas de estaciones y datos satelitales para estudiar el clima del siglo XX y evaluar el desempeno de los modelos climaticos. Con un enfoque centrado en la precipitacion, tambien se analizan factores como la temperatura superficial del mar, la presion al nivel del mar y los vientos que influyen en las variaciones estacionales de la precipitacion. La media del ensamble del CMIP3 y el RCM captan satisfactoriamente las peculiaridades de la circulacion atmosferica de gran escala en la region, pero no asi el ciclo estacional bimodal caracteristico de la precipitacion. La aridez en epocas de lluvias prevista en escenarios de cambio climatico en la region se ha abordado en estudios previos, pero la magnitud de la variacion es muy incierta en las simulaciones tanto del GCM como del RCM. La disminucion proyectada es mayor al inicio de la temporada de lluvias y suprime la sequia del medio verano en el Caribe occidental. Las simulaciones del RCM muestran avances respecto del GCM, sobre todo por sus mejores representaciones de la extension territorial, pero su desempeno depende en gran medida de la conduccion del GCM. El presente estudio destaca la necesidad de contar con observaciones de alta resolucion y comparar simulaciones de modelos climaticos para entender a fondo el cambio climatico y su impacto en las pequenas islas del Caribe.

Climate Change and the Caribbean: Review and Response

Caribbean economies, lifestyles, activities, practices and operational cycles are intricately linked to climate, making them vulnerable to its variations and/or changes. As examples, climate extremes impact agriculture, fisheries, health, tourism, water availability, recreation, and energy usage, among other things. There is however limited incorporation of climate information in the long term developmental plans and policies of the region. This is in part due to a knowledge deficit about climate change, it’s likely manifestation in the region and the possible impact on Caribbean societies. In this paper, a review of the growing bank of knowledge about Caribbean climate science; variability and change is undertaken. Insight is offered into the basic science of climate change, past trends and future projections for Caribbean climate, and the possible implications for the region. In the end a case is made for a greater response to the threats posed by climate change on the basis of the sufficiency of our current knowledge of Caribbean climate science. A general profile of what the response may look like is also offered.

The Precis Caribbean Story: Lessons and Legacies

By the beginning of the current century, there was heightened recognition that the Caribbean is highly vulnerable to the effects of climate change. Yet, there was very little climate change science information for the region and at the scale of the small islands that make up most of the region. To fill the gap, a group of regional scientists representing three institutions and four territories (Barbados, Belize, Cuba, and Jamaica) initiated a project to provide dynamically downscaled climate change information for the Caribbean. The Providing Regional Climates for Impacts Studies (PRECIS)-Caribbean initiative was premised on a shared workload with goals to build regional capacity to provide climate change information for the region from within the region, to provide much needed climate information in the shortest possible time frame, and to create a platform for sharing the information as widely as possible. Ten years later offers the opportunity for retrospection and evaluation, particularly since a phas...

Characterization of Future Caribbean Rainfall and Temperature Extremes across Rainfall Zones

End-of-century changes in Caribbean climate extremes are derived from the Providing Regional Climate for Impact Studies (PRECIS) regional climate model (RCM) under the A2 and B2 emission scenarios across five rainfall zones. Trends in rainfall, maximum temperature, and minimum temperature extremes from the RCM are validated against meteorological stations over 1979–1989. The model displays greater skill at representing trends in consecutive wet days (CWD) and extreme rainfall (R95P) than consecutive dry days (CDD), wet days (R10), and maximum 5-day precipitation (RX5). Trends in warm nights, cool days, and warm days were generally well reproduced. Projections for 2071–2099 relative to 1961–1989 are obtained from the ECHAM5 driven RCM. Northern and eastern zones are projected to experience more intense rainfall under A2 and B2. There is less consensus across scenarios with respect to changes in the dry and wet spell lengths. However, there is indication that a drying trend may be manifest over zone 5 (Trinidad and northern Guyana). Changes in the extreme temperature indices generally suggest a warmer Caribbean towards the end of century across both scenarios with the strongest changes over zone 4 (eastern Caribbean).

Future Caribbean Climates in a World of Rising Temperatures: The 1.5 vs 2.0 Dilemma

AbstractA 10-member ensemble from phase 5 of the Coupled Model Intercomparison Project (CMIP5) is used to analyze the Caribbean’s future climate when mean global surface air temperatures are 1.5°, 2.0°, and 2.5°C above preindustrial (1861–1900) values. The global warming targets are attained by the 2030s, 2050s, and 2070s respectively for RCP4.5. The Caribbean on average exhibits smaller mean surface air temperature increases than the globe, although there are parts of the region that are always warmer than the global warming targets. In comparison to the present (using a 1971–2000 baseline), the Caribbean domain is 0.5° to 1.5°C warmer at the 1.5°C target, 5%–10% wetter except for the northeast and southeast Caribbean, which are drier, and experiences increases in annual warm spells of more than 100 days. At the 2.0°C target, there is additional warming by 0.2°–1.0°C, a further extension of warm spells by up to 70 days, a shift to a predominantly drier region (5%–15% less than present day), and a greater...

Increasing the Accuracy and Automation of Fractional Vegetation Cover Estimation from Digital Photographs

The use of automated methods to estimate fractional vegetation cover (FVC) from digital photographs has increased in recent years given its potential to produce accurate, fast and inexpensive FVC measurements. Wide acceptance has been delayed because of the limitations in accuracy, speed, automation and generalization of these methods. This work introduces a novel technique, the Automated Canopy Estimator (ACE) that overcomes many of these challenges to produce accurate estimates of fractional vegetation cover using an unsupervised segmentation process. ACE is shown to outperform nine other segmentation algorithms, consisting of both threshold-based and machine learning approaches, in the segmentation of photographs of four different crops (oat, corn, rapeseed and flax) with an overall accuracy of 89.6%. ACE is similarly accurate (88.7%) when applied to remotely sensed corn, producing FVC estimates that are strongly correlated with ground truth values.

Estimating damages from climate-related natural disasters for the Caribbean at 1.5 °C and 2 °C global warming above preindustrial levels

This paper examines historical and future changes in normalised damages resulting from climate-related natural disasters for the Caribbean. Annualised damages of USD824 million are shown to be non-stationary over the historical period 1964 to 2013. Perturbations of (i) sea surface temperatures (SST) in the tropical North Atlantic (TNA) and (ii) the Atlantic multi-decadal oscillation (AMO) appear to be associated with historical damages. Both the TNA and AMO are known modulators of hurricane activity and rainfall amounts in the Caribbean. Indicative future damages are determined using (i) cumulative distribution functions (CDFs) of perturbed climate states and (ii) an artificial neural network (ANN) model of damages using projected TNA values and the state of the AMO derived from an ensemble of five coupled model intercomparison project phase 5 (CMIP5) global climate models (GCMs) run under the RCP 4.5 scenario. Estimates of future damages are determined when global mean surface temperatures (GMST) reach and exceed 1.5 °C above preindustrial levels. Annual normalised damages may potentially increase to at least USD1395 million or close to double for 1.5 °C. At 2 °C, higher damages may occur; however, large uncertainty across all GCMs prohibits the identification of significant difference between 1.5 and 2 °C. Significant differences in damages do, however, exist for at least two of the GCMs for the two climate states. The robustness of the results is discussed in light of a number of issues, including limitations associated with the data.

The Regional Climate Science Initiative: Value Added and Lessons Learnt

one of the consequences of the veRy Active huRRicAne seAson of 2017, which included two Category 5 storms hitting the eastern Caribbean within weeks of each other, has been increased discussion about climate change. ere has been robust discourse in the public media1 and now emerging in the peerreviewed literature2 about the potential role climate change might have played in making the season extraordinary. One suggestion is that even if hurricane records are too short and uncertain to definitively prove anthropogenic influence, when the season is viewed in the context of other historical climate trends, or placed against the backdrop of projected trends for the Caribbean region, the argument for a climate change imprint is significantly bolstered.3 In this article, we argue that the existence of historical and future climate data for the Caribbean, the greater number of peer reviewed analyses now available, and the larger cadre of regional climate scientists who are able to participate in climate change discussions of this nature are not accidental, and represents a significant improvement over the situation at the beginning of the current century. Rather, the growing amount of data, publications and expertise on Caribbean climate is in large part due to a deliberate regional climate science initiative involving a number of Caribbean institutions pursuing a defined regional science agenda. is article examines the history of the regional climate science initiative, including noteworthy milestones (section 2). It also attempts to assess the value added to the region in adopting a regional collaborative approach to generating climate science information

The Climate Studies Group Mona

Introduction The Climate Studies Group Mona (CSGM) was launched in 1994, in the Department of Physics, the University of the West Indies, Mona campus. The initiative was set in motion by Professor the Honourable A. Anthony Chen, O. M., Professor of Applied Physics. During the formative years we were given valuable assistance from by the Centre for Ocean Land Atmosphere Studies (COLA), the Inter American Institute (IAI) for A Global Change Research and The University of the West Indies Research Fellowship Programme. The group, which now comprises lecturers, postgraduate and undergraduate students, and associate members (former students), has made significant contributions to the study of Caribbean climate. These include, identifying atmospheric and oceanic influences on our climate, investigating climate change and its impact, isolating the relation between climate and crop yield for sugar cane, climate and incidences of dengue fever outbreak, and investigating renewable energy prospects for Jamaica. This article outlines the work of the CSGM and its significance in a local, regional and international context. Mission At its inception, the primary aim of CSGM was to learn the techniques of dynamic modelling of climate by numerical models. Since then, however, the groups activities have expanded to include applications of climate prediction, projections of regional climate change, and prospecting for alternative energy resources as a means of reducing energy costs and greenhouse gas emissions. Therefore the mission of the CSGM is as follows: * To investigate and understand the mechanisms responsible for a) the mean climate and b) extremes in climate in both Jamaica and the wider Caribbean; * To use this understanding to predict climate on a seasonal and annual basis; * To promote awareness of global warming and to determine how anthropogenic climate change will manifest itself in the Caribbean region; * To investigate the potential for exploiting renewable energy resources; and * To investigate and promote the advantageous uses of climate prediction in socio-economic sectors Pioneering Work Over the last 14 years, the CSGM has been involved in ground-breaking research that has resulted in significant contributions to atmospheric science and society. These include: * The mapping of the average solar radiation available to Jamaica, the results of which highlight the strong prospects of solar photovoltaics applications. * The modelling of wind speed and power across Jamaica, thereby identifying regions with good potential for utility-scale wind power. * Identifying an increase in early season (May-July) rainfall amounts in the year following the onset of an El Nino event. This is in contrast to the amplified dryness over the Caribbean frequently reported in literature in relation to the onset of El Nino. * Elucidating the impact of meteorological drought on sugar cane productions. * Clarifying the role of both the Atlantic and Pacific Oceans in modulating seasonal rainfall over the Caribbean and adjacent Caribbean regions. * The issuing of seasonal Precipitation Outlooks for Jamaica, made possible by the creation of statistical models for the early (May- July) and late (August-October) rainfall seasons for the Caribbean and mid-dry season (January-February) rainfall for the eastern Caribbean and Jamaica. * Proposing the atmospheric circulation patterns that facilitate the rainfall gradient pattern evident during the dry season (November- April) for the mature El Nino. It was found that the gradient pattern involved higher than normal rainfall over the northern Caribbean (north of 20°) and below normal over the southern Caribbean in relation to El Nino. * Identifying the evidence of climate change over the Caribbean particularly with respect to temperature. * The development of a Caribbean Climate Interactive Database. …