Sensitivity of terrestrial precipitation trends to the structural evolution of sea surface temperatures

Pronounced intermodel differences in the projected response of land surface precipitation (LSP) to future anthropogenic forcing remain in the Coupled Model Intercomparison Project Phase 5 model integrations. A large fraction of the intermodel spread in projected LSP trends is demonstrated here to be associated with systematic differences in simulated sea surface temperature (SST) trends, especially the representation of changes in (i) the interhemispheric SST gradient and (ii) the tropical Pacific SSTs. By contrast, intermodel differences in global mean SST, representative of differing global climate sensitivities, exert limited systematic influence on LSP patterns. These results highlight the importance to regional terrestrial precipitation changes of properly simulating the spatial distribution of large-scale, remote changes as reflected in the SST response to increasing greenhouse gases. Moreover, they provide guidance regarding which region-specific precipitation projections may be potentially better constrained for use in climate change impact assessments

Uncertainties in the timing of unprecedented climates

The question of when the signal of climate change will emerge from the background noise of climate variability—the ‘time of emergence’—is potentially important for adaptation planning. Mora et al.1 presented precise projections of the time of emergence of unprecedented regional climates. However, their methodology produces artificially early dates at which specific regions will permanently experience unprecedented climates and artificially low uncertainty in those dates everywhere. This overconfidence could impair the effectiveness of climate risk management decisions 2. There is a Reply to this Brief Communication Arising by Mora, C. et al. Nature 511, http://dx.doi.org/10.1038/nature13524 (2014)

Significantly wetter or drier future conditions for one to two thirds of the world’s population

Future projections of precipitation are uncertain, hampering effective climate adaptation strategies globally. Our understanding of changes across multiple climate model simulations under a warmer climate is limited by this lack of coherence across models. Here, we address this challenge introducing an approach that detects agreement in drier and wetter conditions by evaluating continuous 120-year time-series with trends, across 146 Global Climate Model (GCM) runs and two elevated greenhouse gas (GHG) emissions scenarios. We show the hotspots of future drier and wetter conditions, including regions already experiencing water scarcity or excess. These patterns are projected to impact a significant portion of the global population, with approximately 3 billion people (38% of the world’s current population) affected under an intermediate emissions scenario and 5 billion people (66% of the world population) under a high emissions scenario by the century’s end (or 35-61% using projections of future population). We undertake a country- and state-level analysis quantifying the population exposed to significant changes in precipitation regimes, offering a robust framework for assessing multiple climate projections

THE CC1 PROJECT – SYSTEM FOR PRIVATE CLOUD COMPUTING

The main features of the Cloud Computing system developed at IFJ PAN are described. The project is financed from the structural resources provided by the European Commission and the Polish Ministry of Science and Higher Education (Innovative Economy, National Cohesion Strategy). The system delivers a solution for carrying out computer calculations on a Private Cloud computing infrastructure. It consists of an intuitive Web based user interface, a module for the users and resources administration and the standard EC2 interface implementation. Thanks to the distributed character of the system it allows for the integration of a geographically distant federation of computer clusters within a uniform user environment

A USCLIVAR Project to Assess and Compare the Responses of Global Climate Models to Drought-Related SST Forcing Patterns: Overview and Results

The USCLI VAR working group on drought recently initiated a series of global climate model simulations forced with idealized SST anomaly patterns, designed to address a number of uncertainties regarding the impact of SST forcing and the role of land-atmosphere feedbacks on regional drought. Specific questions that the runs are designed to address include: What are the mechanisms that maintain drought across the seasonal cycle and from one year to the next? What is the role of the leading patterns of SST variability, and what are the physical mechanisms linking the remote SST forcing to regional drought, including the role of land-atmosphere coupling? The runs were carried out with five different atmospheric general circulation models (AGCM5), and one coupled atmosphere-ocean model in which the model was continuously nudged to the imposed SST forcing. This paper provides an overview of the experiments and some initial results focusing on the responses to the leading patterns of annual mean SST variability consisting of a Pacific El Nino/Southern Oscillation (ENSO)-like pattern, a pattern that resembles the Atlantic Multi-decadal Oscillation (AMO), and a global trend pattern. One of the key findings is that all the AGCMs produce broadly similar (though different in detail) precipitation responses to the Pacific forcing pattern, with a cold Pacific leading to reduced precipitation and a warm Pacific leading to enhanced precipitation over most of the United States. While the response to the Atlantic pattern is less robust, there is general agreement among the models that the largest precipitation response over the U.S. tends to occur when the two oceans have anomalies of opposite sign. That is, a cold Pacific and warm Atlantic tend to produce the largest precipitation reductions, whereas a warm Pacific and cold Atlantic tend to produce the greatest precipitation enhancements. Further analysis of the response over the U.S. to the Pacific forcing highlights a number of noteworthy and to some extent unexpected results. These include a seasonal dependence of the precipitation response that is characterized by signal-to-noise ratios that peak in spring, and surface temperature signal-to-noise ratios that are both lower and show less agreement among the models than those found for the precipitation response. Another interesting result concerns what appears to be a substantially different character in the surface temperature response over the U.S. to the Pacific forcing by the only model examined here that was developed for use in numerical weather prediction. The response to the positive SST trend forcing pattern is an overall surface warming over the world's land areas with substantial regional variations that are in part reproduced in runs forced with a globally uniform SST trend forcing. The precipitation response to the trend forcing is weak in all the models

Global exposure of population and land‐use to meteorological droughts under different warming levels and SSPs: a CORDEX‐based study

Global warming is likely to cause a progressive drought increase in some regions, but how population and natural resources will be affected is still underexplored. This study focuses on global population, forests, croplands and pastures exposure to meteorological drought hazard in the 21st century, expressed as frequency and severity of drought events. As input, we use a large ensemble of climate simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX), population projections from the NASA-SEDAC dataset and land-use projections from the Land-Use Harmonization 2 project for 1981–2100. The exposure to drought hazard is presented for five Shared Socioeconomic Pathways (SSP1-SSP5) at four Global Warming Levels (GWLs: 1.5°C to 4°C). Results show that considering only Standardized Precipitation Index (SPI; based on precipitation), the SSP3 at GWL4 projects the largest fraction of the global population (14%) to experience an increase in drought frequency and severity (versus 1981–2010), with this value increasing to 60% if temperature is considered (indirectly included in the Standardized Precipitation-Evapotranspiration Index, SPEI). With SPEI, considering the highest GWL for each SSP, 8 (for SSP2, SSP4, SSP5) and 11 (SSP3) billion people, that is, more than 90%, will be affected by at least one unprecedented drought. For SSP5 at GWL4, approximately 2 × 10$^{6}$ km$^{2}$ of forests and croplands (respectively, 6% and 11%) and 1.5 × 10$^{6}$ km$^{2}$ of pastures (19%) will be exposed to increased drought frequency and severity according to SPI, but for SPEI this extent will rise to 17 × 10$^{6}$ km$^{2}$ of forests (49%), 6 × 10$^{6}$ km$^{2}$ of pastures (78%) and 12 × 10$^{6}$ km$^{2}$ of croplands (67%), being mid-latitudes the most affected. The projected likely increase of drought frequency and severity significantly increases population and land-use exposure to drought, even at low GWLs, thus extensive mitigation and adaptation efforts are needed to avoid the most severe impacts of climate change

Trees, forests and water: Cool insights for a hot world

Forest-driven water and energy cycles are poorly integrated into regional, national, continental and global decision-making on climate change adaptation, mitigation, land use and water management. This constrains humanity’s ability to protect our planet’s climate and life-sustaining functions. The substantial body of research we review reveals that forest, water and energy interactions provide the foundations for carbon storage, for cooling terrestrial surfaces and for distributing water resources. Forests and trees must be recognized as prime regulators within the water, energy and carbon cycles. If these functions are ignored, planners will be unable to assess, adapt to or mitigate the impacts of changing land cover and climate. Our call to action targets a reversal of paradigms, from a carbon-centric model to one that treats the hydrologic and climate-cooling effects of trees and forests as the first order of priority. For reasons of sustainability, carbon storage must remain a secondary, though valuable, by-product. The effects of tree cover on climate at local, regional and continental scales offer benefits that demand wider recognition. The forest- and tree-centered research insights we review and analyze provide a knowledge-base for improving plans, policies and actions. Our understanding of how trees and forests influence water, energy and carbon cycles has important implications, both for the structure of planning, management and governance institutions, as well as for how trees and forests might be used to improve sustainability, adaptation and mitigation efforts

The simulated impact of land cover change on climate extremes in eastern Australia

In this paper, we investigate the impact of historical land cover change on climate extremes in eastern Australia by analysing data from an ensemble of model simulations using CSIRO AGCM. The model simulations were performed for two sets of prescribed land surface parameters representative of pre- European and modern-day land cover conditions. To evaluate the impact of historical land cover change on Australian regional climate, the CSIRO AGCM was used to complete two sets of model simulations (ensemble of 10 each) for the period 1951-2003. In this study, we used the CSIRO climate model consisting of atmospheric and land surface components forced by observed sea surface temperature and sea ice data for the period 1951-2003 (Rayner et al., 1996). This experimental set-up followed the design of the Climate of the 20th Century project (Folland et al., 2002) and allows for direct comparison between observed and model simulated ENSO events which are known to strongly influence Australian climate. The only difference between the experiments was the land surface characteristics for Australian continent used by the CSIRO model. The first set of model simulations used the modern-day and the second used the pre-European land cover characteristics. Outside Australia, the land cover characteristics were set at modern day conditions for both experiments. The modern-day land surface conditions were derived using data from the AVHRR satellite imagery for the period 1981 to 2001 at an 8km spatial footprint (Lawrence, 2004). The monthly long-term average values of vegetation cover class, leaf area index, vegetation fraction and surface albedo were used as an input to the Simple Biosphere Model (SiB) derivation methods described in Sellers et al.(1986) to compute land surface characteristics used by the CSIRO climate model. Pre-clearing land surface parameters of vegetation fraction, leaf area index, surface albedo and stomatal resistance were generated by extrapolating the modern-day monthly values of remnant native vegetation to the pre-European coverage (see Lawrence, 2004). The extrapolation was performed for the Australian continent at an ~8×8km resolution and aggregated to ~200×200km resolution used by CSIRO AGCM using the approach of Shuttleworth, (1991), thereby ensuring the seasonal dynamics captured by satellite imagery were represented in pre-European parameters. The impact of land cover change on mean climate in Australia was described in McAlpine et al.(2007). The results showed a statistically significant increase in mean annual surface temperature and decrease in mean annual rainfall in southeast Australia. On a seasonal basis, the impact of land cover change was strongest during the summer season and was especially pronounced during strong El Nino events such as the 2002/03 event. In this paper, we focus on the impact of land cover change on the climate extremes by analysing the daily statistics of rainfall and temperature change over the period 1951-2003. To quantify the changes in annual distribution of daily rainfall and temperature, we computed the probability distribution functions (pdfs) of daily maximum surface temperature (tmax) and daily rainfall for selected locations in eastern Australia. In addition, the daily rainfall and temperature data was used to derive climate extreme indices of dry days (number of days with rainfall <1 mm), daily rainfall intensity (total annual rainfall / number of rain days), rain days (number of days with rainfall ≥1 mm) and hot days (number of days with tmax ≥35ºC) (Frich et al., 2002). The analysis results showed statistically significant changes in the annual pdfs of rainfall and temperature in southeast Australia, which corresponds well with areas with largest fragmentation of pre-European vegetation cover. The fragmentation of vegetation resulted in an increase in the number of hot days, a decrease in daily rainfall intensity and a decrease in cumulative rainfall on rainy days in southeast Australia. These changes were especially pronounced during strong El Nino events

Bubbles about history. Polish historical comics

Praca jest spojrzeniem na komiks historyczny w Polsce.Rozdział pierwszy przedstawia chronologiczny rozwój komiksu w Polsce i na świecie, przedstawia również przegląd definicji pojęcia komiks, porusza również problem lektury, czytelnika i jego umiejętności w odczytywaniu treści komiksów.Rozdział drugi jest próbą wyodrębnienia komiksu historycznego jako gatunku, a także omówieniem strategii ukazywania historii w obrazkowych opowiadaniach.Ukazuje również rozwój komiksu historycznego w naszym kraju, a także krótką analizę treści omawianych tytułów.Rozdział trzeci jest próbą szczegółowej analizy trzech komiksów historycznych:"Maus" Arta Spiegelmana, "Achtung Zelig! Druga Wojna" Krystiana Rosińskiego i Krzysztofa Gawronkiewicza, "Westerplatte: Załoga śmierci” Krzysztofa Wyrzykowskiego i Mariusza Wójtowicza-PodchorskiegoThe diploma paper is an attempt to look at historical comics in Poland.First chapter presents chronological development of comics both in Poland and in the world. Is also covers some definitions of comics, problems in reading ,reader and abilities to understand the content.Second chapter shows historical comics as a separate type and a strategy of presenting a story in drawings(pictures).It presents the evolution of historical comics in Poland, and a short analysis of covered texts.The last chapter is an attempt to detailed analysis of three historical comics:"Maus" by Art Spiegelman, "Achtung Zelig! Druga Wojna" by Krystian Rosiński & Krzysztof Gawronkiewicz, "Westerplatte: Załoga śmierci” by Krzysztof Wyrzykowski & Mariusz Wójtowicz-Podchorsk

Reasons for decline in eastern Australia's rainfall

The CSIRO Global Climate Model set up was used to conduct attribution experiments to investigate the impact of changes in long-term radiative forcing due to solar variability, increasing CO, and stratospheric ozone depletion on the regional rainfall trends. Results show that both increasing CO and decreasing stratospheric ozone contribute to observed mean sea level pressure changes in the Southern Hemisphere, with ozone having the strongest impact during the austral spring and summer, and CO during the austral winter. Furthermore, CO and ozone changes have opposite effects on rainfall changes in eastern Australia and the South Pacific Convergence Zone