מאמרים

מרכז הידע הישראלי להערכות לשינויי אקלים
2011

Changes in precipitation with climate change

There is a direct influence of global warming on precipitation. Increased heating leads to greater evaporation and thus surface drying, thereby increasing the intensity and duration of drought. However, the water holding capacity of air increases by about 7% per 1°C warming, which leads to increased water vapor in the atmosphere. Hence, storms, whether individual thunderstorms, extratropical rain or snow storms, or tropical cyclones, supplied with increased moisture, produce more intense precipitation events. Such events are observed to be widely occurring, even where total precipitation is decreasing: ‘it never rains but it pours!’ This increases the risk of flooding. The atmospheric and surface energy budget plays a critical role in the hydrological cycle, and also in the slower rate of change that occurs in total precipitation than total column water vapor. With modest changes in winds, patterns of precipitation do not change much, but result in dry areas becoming drier (generally throughout the subtropics) and wet areas becoming wetter, especially in the mid- to high latitudes: the ‘rich get richer and the poor get poorer’. This pattern is simulated by climate models and is projected to continue into the future. Because, with warming, more precipitation occurs as rain instead of snow and snow melts earlier, there is increased runoff and risk of flooding in early spring, but increased risk of drought in summer, especially over continental areas. However, with more precipitation per unit of upward motion in the atmosphere, i.e. ‘more bang for the buck’, atmospheric circulation weakens, causing monsoons to falter. In the tropics and subtropics, precipitation patterns are dominated by shifts as sea surface temperatures change, with El Niño a good example. The volcanic eruption of Mount Pinatubo in 1991 led to an unprecedented drop in land precipitation and runoff, and to widespread drought, as precipitation shifted from land to oceans and evaporation faltered, providing lessons for possible geoengineering. Most models simulate precipitation that occurs prematurely and too often, and with insufficient intensity, resulting in recycling that is too large and a lifetime of moisture in the atmosphere that is too short, which affects runoff and soil moisture.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

Empirical Orthogonal Function analysis of the palmer drought indices

The aim of the paper is to employ Empirical Orthogonal Function (EOF) analysis to drought indices including Palmer Drought Severity Index (PDSI), Palmer Hydrological Drought Index (PHDI), Palmer Moisture Anomaly (Z) Index (Z-Index), Weighted Palmer Drought Severity Index (WPDSI), and Water Deficit (P–PET) Index and to compare their resultant spatial patterns across Turkey. In this respect, the PDSI, PHDI, Z, WPDSI, Aridity Index (AI) and P–PET Index values are calculated based on observed monthly temperature and precipitation values of the 96 Turkish meteorological stations for the 1929–2009 period, and gridded available water holding capacities (AWHC) in 1-m soil depth are extracted from the soil data sets of the Oak Ridge National Laboratory Distributed Active Archive Centre (ORNL DAAC). By considering the strong match among the PDSI, PHDI, and WPDSI based on the results of the patterns of the first EOFs (EOF1) with the highest eigenvalue, we suggest that using and applying one of these drought indices could be adequate for a drought analysis in Turkey. On the other hand, it is evident that the significant results from the EOF2, EOF3 and EOF4 loadings of the PHDI and WPDSI indices have a similar pattern across Turkey. Therefore, with respect to the geographical autocorrelation and magnitudes of the loading values, it is explained that the PDSI and WPDSI in particular could have originated from the same physical process, and one may have a preference for the effective usage of a combination of PDSI, PHDI and Z-Index. Consequently, in a multi-purpose medium- and long-term drought management plan for Turkey or in any country having similar climatic and physical geographical conditions, using one of the three drought indices along with the Z-Index could be acceptable for successful applications.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

Drought analysis in Jordan under current and future climates

Droughts have adverse socioeconomic, agricultural, and environmental impacts that can be reduced by assessing and forecasting drought behavior. The paper presents detailed analyses of both meteorological and vegetative droughts over the period from 1970 to 2005. Standardized Precipitation Index (SPI) and Normalized Difference Vegetation Index (NDVI) have been used to quantify drought according to severity, magnitude and spatial distribution at the Hashemite Kingdom of Jordan. Results suggest that the country faced during the past 35 years frequent non-uniform drought periods in an irregular repetitive manner. Drought severity, magnitudes and life span increased with time from normal to extreme levels especially at last decade reaching magnitudes of more than 4. Generated NDVI maps spatial analyses estimate crop-area percentage damage due to severe and extremely severe drought events occurred during October, December, and February of 2000 to be about 10%, 45%, and 30%, respectively. In response to drought spatial extent, the paper suggest the presence of two drought types, local drought acting on one or more geographical climatic parts and national drought, of less common but more severe, that extend over the whole country. Droughts in Jordan act intensively during January, February and March and tend to shift position with time by alternative migrations from southern desert parts to northern desert parts and from the eastern desert parts to highlands and Jordan Rift Valley (JRV) at the west. The paper also investigates the potential use of Global Climate Model’s (GCM) to forecast future drought events from 2010 till 2040. Tukey HSD test indicates that ECHAM5OM GCM is capable to predicted rainfall variation at the country and suggests future droughts to become more intensive at the northern and southern desserts with 15% rainfall reduction factor, followed by 10% reduction at the JRV, and 5% at the highlands.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

Adapting to climate change- UK climate projection

The Earth’s climate is changing. Global temperatures are predicted to continue rising, bringing changes in weather patterns, rising sea levels and increased frequency and intensity of extreme weather for the UK. The extent of change will depend greatly on how successfully the world cuts its greenhouse gas emissions. We need to understand how our climate might change so that we can prepare. Organisations need good evidence, which includes a measure of the uncertainties involved, to help them consider the risks that a changing climate might pose and plan what they should do to increase resilience and reduce those risks. The UK Climate Projections 2009 have been developed to do this.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2003

Late Holocene climates of the Near East deduced from Dead Sea level variations and modern regional winter rainfall

The Dead Sea is a terminal lake of one of the largest hydrological systems in the Levant and may thus be viewed as a large rain gauge for the region. Variations of its level are indicative of the climate variations in the region. Here, we present the decadal- to centennial-resolution Holocene lake-level curve of the Dead Sea. Then we determine the regional hydroclimatology that affected level variations. To achieve this goal we compare modern natural lake-level variations and instrumental rainfall records and quantify the hydrology relative to lake-level rise, fall, or stability. To quantify that relationship under natural conditions, rainfall data pre-dating the artificial Dead Sea level drop since the 1960s are used. In this respect, Jerusalem station offers the longest uninterrupted pre-1960s rainfall record and Jerusalem rains serve as an adequate proxy for the Dead Sea headwaters rainfall. Principal component analysis indicates that temporal variations of annual precipitation in all stations in Israel north of the current 200 mm yr−1 average isohyet during 1940–1990 are largely synchronous and in phase (∼70% of the total variance explained by PC1). This station also represents well northern Jordan and the area all the way to Beirut, Lebanon, especially during extreme drought and wet spells. We (a) determine the modern, and propose the past regional hydrology and Eastern Mediterranean (EM) climatology that affected the severity and length of droughts/wet spells associated with multiyear episodes of Dead Sea level falls/rises and (b) determine that EM cyclone tracks were different in average number and latitude in wet and dry years in Jerusalem. The mean composite sea level pressure and 500-mb height anomalies indicate that the potential causes for wet and dry episodes span the entire EM and are rooted in the larger-scale northern hemisphere atmospheric circulation. We also identified remarkably close association (within radiocarbon resolution) between climatic changes in the Levant, reflected by level changes, and culture shifts in this region.
מידע נוסף

מאמרים ופרסומים אחרונים

מרכז הידע הישראלי להערכות לשינויי אקלים
2015

Periodic Report Summary 1 - DYNAMIC (DYNamic feedbacks of climate impacts on current Adaptation and Mitigation Investment Choice)

The DYNAMIC (DYNamic feedbacks of climate impacts on current Adaptation and Mitigation Investment Choice) project proposes a novel framework to evaluate the economic consequences of climate change impacts and related policy responses.
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2015

בחינת תרומת קבוצות סוציו אקונומיות בישראל לפליטות גזי חממה מצריכת מזון ביתי

לייצור המזון, במיוחד בחקלאות התעשייתית, נודעת השפעה ממשית על היקף פליטות גזי חממה באופן ישיר או עקיף. גזי חממה אלו נוצרים בכל שלבי מחזור החיים של המזון, החל משלב החקלאות ותשומותיו, דרך הייצור, הפצה, קירור, קמעונאות, הכנת המזון בבית וכלה בסילוק הפסולת.למעשה, בעוד שבמחקרים השונים קיימת הסכמה על כך שפליטות גזי חממה מייצור המזון וצריכתו מהוות חלק משמעותי מפליטות גזי החממה בעולם, המחלוקת המחקרית נסובה סביב הערכת היקף הפליטות. לדוגמא, לפי דוח של האו"ם מ- 2014 14.5% מפליטות גזי החממה כתוצאה מפעילו
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2014

Explaining Extreme Weather Events of 2013 from a Climate Perspective

The annual Bulletin of the American Meteorological Society (BAMS) special issue on the attribution of last year’s extreme weather events is published today. This year’s issue “explaining extreme events of 2013 – from a climate perspective” includes two papers led by researchers from our climateprediction. This is a highly-cited and influential annual publication coined in 2012 asking whether and to what extent anthropogenic climate change altered the risk of major extreme weather events of the p
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2014

Lima call for climate action- Decision

Climate Action & UNEP delivered their fifth annual Sustainable Innovation Forum on December 9 in Lima. This year’s event brought together close to 500 leaders from key United Nations bodies, governments, international & regional companies and leading non-governmental organisations (NGO's).
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2012

Climate Prediction for Adaptation: Who needs what?

The role of short- and long-term climate predictions in determining the success of adaptation to climate change is investigated. A simple theoretical model that captures the relationship between adaptive performance, decision structure, and prediction accuracy at different temporal scales is developed, and its implications deduced. It is shown that users who face high adjustment costs (i.e. are inflexible) depend more heavily on accurate long-term predictions than those who are able to adjust
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2012

UK climate change risk assessment: government report

The Government published the UK Climate Change Risk Assessment (CCRA) on 25 January 2012, the first assessment of its kind for the UK and the first in a 5 year cycle. It sets out the main priorities for adaptation in the UK under 5 key themes identified in the CCRA 2012 Evidence Report - Agriculture and Forestry; Business, industries and Services; Health and Wellbeing; Natural Environment and Buildings and Infrastructure - and describes the policy context, and action already in place to tackle
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

2011 Bonn Declaration of Mayors

This declaration is the outcome document of the Mayors Adaptation Forum, which forms the Mayors segment of the Resilient Cities 2011 congress. It highlights the need to build resilience to disasters as a critical issue. It also signals the need to take appropriate action to build local capacities in reducing risk to disasters including those exacerbated by climate change.
The declaration advocates for the implementation of the following: (i) mainstreaming new adaptation and resilience standard
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

A double-resolution transient RCM climate change

A double-resolution regional experiment on hydrodynamic simulation of climate over the eastern Mediterranean (EM) region was performed using an International Center for Theoretical Physics, Trieste RegCM3 model. The RegCM3 was driven from the lateral boundaries by the data from the ECHAM5/MPI-OM global climate simulation performed at the MPI-M, Hamburg and based on the A1B IPCC scenario of greenhouse gases emission. Two simulation runs for the time period 1960-2060, employing spatial resolutions
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

Climate Change Adaptation and Real Option Evaluation: A Case Study in Campeche, Mexico

This report illustrates the application of a (relatively) new method to guide decision making under high (and unknowable) levels of uncertainty. The approach allows for the identification of robust policy options that are economically beneficial under different scenarios and varying levels uncertainty. Option value techniques are commonly employed in the finance literature to identify investment decisions that are resilient across a spectrum of outcomes. The methods are technically advanced
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2011

ipcc summary for policymakers

The Working Group III Special Report on Renewa
ble Energy Sources and Climate Change
Mitigation (SRREN) presents an assessment of th
e literature on the scientific, technological,
environmental, economic and social aspects of
the contribution of six renewable energy (RE)
sources to the mitigation of climate change. It is
intended to provide policy relevant information to
governments, intergovernmental processes and ot
her interested parties. This Summary for
Policymakers provides an ov
מידע נוסף
מרכז הידע הישראלי להערכות לשינויי אקלים
2008

Climate change- vulnerability and adaptation indicators

The purpose of this Technical Paper is to rehearse some fundamental concepts surrounding the
development and delineation of adaptation indicators. It builds upon the outputs of an Expert meeting
on climate change vulnerability and adaptation indicators (Budapest, September 2008) and on the
contents of a Background Paper that was prepared for the meeting.
מידע נוסף
אתר זה אינו נתמך על ידי הדפדפן שלך אנא הורד גוגל כרום
נגישות
גודל טקסט:
א א א
שינוי צבעי האתר:
מקשי קיצור
?

לחיצה חוזרת ונשנית על המקש Tab תעביר אתכם בין הקישורים והאזורים השונים בעמוד.

הפעלת מקשי הקיצור תלויה בדפדפן שבו אתם משתמשים:

ב Internet Explorer ובChrome ובגרסאות ישנות של Firefox: לחצו על מקש Alt ועל מקש המספר או האות על-פי הרשימה. ב Firefox 3 ומעלה: לחצו על המקשים Alt + Shift + המספר או האות.

S - עבור לתוכן העמוד
1 - עמוד הבית
2 - חיפוש