Emission pathways to achieve 2.0°C and 1.5°C climate targets

We investigated the feasibilities of 2.0°C and 1.5°C climate targets by considering the abatement potentials of a full suite of greenhouse gases, pollutants, and aerosols. We revised the inter-temporal dynamic optimization model DICE-2013R by introducing three features as follows. First, we applied a new marginal abatement cost curve derived under moderate assumptions regarding future socioeconomic development—the Shared Socioeconomic Pathways 2 (SSP2) scenario. Second, we addressed emission abatement for not only industrial CO2 but also land-use CO2, CH4, N2O, halogenated gases, CO, volatile organic compounds, SOx, NOx, black carbon and organic carbon. Third, we improved the treatment of the non-CO2 components in the climate module based on MAGICC 6.0. We obtained the following findings: (1) It is important to address the individual emissions in an analysis of low stabilization scenarios because abating land-use CO2, non-CO2 and aerosol emissions also contributes to maintaining a low level of radiative forcing and substantially affects the climate costs. (2) The 2.0°C target can be efficiently reached under the assumptions of the SSP2 scenario. (3) The 1.5°C target can be met with early deep cuts under the assumption of a temperature overshoot, and it will triple the carbon price and double the mitigation cost compared with the 2.0°C case

Reliability and importance of structural diversity of climate model ensembles

PublishedJournal ArticleWe investigate the performance of the newest generation multi-model ensemble (MME) from the Coupled Model Intercomparison Project (CMIP5). We compare the ensemble to the previous generation models (CMIP3) as well as several single model ensembles (SMEs), which are constructed by varying components of single models. These SMEs range from ensembles where parameter uncertainties are sampled (perturbed physics ensembles) through to an ensemble where a number of the physical schemes are switched (multi-physics ensemble). We focus on assessing reliability against present-day climatology with rank histograms, but also investigate the effective degrees of freedom (EDoF) of the fields of variables which makes the statistical test of reliability more rigorous, and consider the distances between the observation and ensemble members. We find that the features of the CMIP5 rank histograms, of general reliability on broad scales, are consistent with those of CMIP3, suggesting a similar level of performance for present-day climatology. The spread of MMEs tends towards being "over-dispersed" rather than "under-dispersed". In general, the SMEs examined tend towards insufficient dispersion and the rank histogram analysis identifies them as being statistically distinguishable from many of the observations. The EDoFs of the MMEs are generally greater than those of SMEs, suggesting that structural changes lead to a characteristically richer range of model behaviours than is obtained with parametric/physical-scheme-switching ensembles. For distance measures, the observations and models ensemble members are similarly spaced from each other for MMEs, whereas for the SMEs, the observations are generally well outside the ensemble. We suggest that multi-model ensembles should represent an important component of uncertainty analysis. © 2013 The Author(s).We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP. For CMIP the US Department of Energy’s Pro- gram for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. M.C. was partially supported by funding from NERC grants NE/I006524/1 and NE/I022841/1. MW is supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101). T.Y., J.D.A, H.S., S.E., M.Y., J.C.H. were supported by the Global Environment Research Fund of the Ministry of the Environment of Japan (S-10, Integrated Climate Assessment – Risks,Uncertainties and Society, ICA-RUS)

How do climate-related uncertainties influence 2 and 1.5 °C pathways?

We investigate how uncertainties in key parameters in the carbon cycle and climate system propagate to the costs of climate change mitigation and adaptation needed to achieve the 2 and 1.5 °C targets by 2100 using a stochastic version of the simple climate model for optimization (SCM4OPT), an integrated assessment model. For the 2 °C target, we find a difference in 2100 CO2 emission levels of 20.5 GtCO2 (− 1.2 GtCO2 to 19.4 GtCO2), whereas this difference is 12.0 GtCO2 (− 6.9 GtCO2 to 5.1 GtCO2) for the 1.5 °C target (17–83% range). Total radiative forcing in 2100 is estimated to be 3.3 (2.7–3.9) Wm−2 for the 2 °C case and 2.5 (2.0–3.0) Wm−2 for the 1.5 °C case. Carbon prices in 2100 are 482 (181–732) USD(2005)/tCO2 and 713 (498–1014) USD(2005)/tCO2 for the 2 and 1.5 °C targets, respectively. We estimate GDP losses in 2100 that correspond to 1.9 (1.2–2.5)% of total gross output for the 2 °C target and 2.0 (1.5–2.7)% for the 1.5 °C target

Changes in extremely hot days under stabilized 1.5 °C and 2.0 °c global warming scenarios as simulated by the HAPPI multi-model ensemble

The half a degree additional warming, prognosis and projected impacts (HAPPI) experimental protocol provides a multi-model database to compare the effects of stabilizing anthropogenic global warming of 1.5 °C over preindustrial levels to 2.0 °C over these levels. The HAPPI experiment is based upon large ensembles of global atmospheric models forced by sea surface temperature and sea ice concentrations plausible for these stabilization levels. This paper examines changes in extremes of high temperatures averaged over three consecutive days. Changes in this measure of extreme temperature are also compared to changes in hot season temperatures. We find that over land this measure of extreme high temperature increases from about 0.5 to 1.5 °C over present-day values in the 1.5 °C stabilization scenario, depending on location and model. We further find an additional 0.25 to 1.0 °C increase in extreme high temperatures over land in the 2.0 °C stabilization scenario. Results from the HAPPI models are consistent with similar results from the one available fully coupled climate model. However, a complicating factor in interpreting extreme temperature changes across the HAPPI models is their diversity of aerosol forcing changes

Half a degree additional warming, prognosis and projected impacts (HAPPI): Background and experimental design

Abstract. The Intergovernmental Panel on Climate Change (IPCC) has accepted the invitation from the UNFCCC to provide a special report on the impacts of global warming of 1.5 °C above pre-industrial levels and on related global greenhouse-gas emission pathways. Many current experiments in, for example, the Coupled Model Inter-comparison Project (CMIP), are not specifically designed for informing this report. Here, we document the design of the half a degree additional warming, projections, prognosis and impacts (HAPPI) experiment. HAPPI provides a framework for the generation of climate data describing how the climate, and in particular extreme weather, might differ from the present day in worlds that are 1.5 and 2.0 °C warmer than pre-industrial conditions. Output from participating climate models includes variables frequently used by a range of impact models. The key challenge is to separate the impact of an additional approximately half degree of warming from uncertainty in climate model responses and internal climate variability that dominate CMIP-style experiments under low-emission scenarios.Large ensembles of simulations (&gt;  50 members) of atmosphere-only models for three time slices are proposed, each a decade in length: the first being the most recent observed 10-year period (2006–2015), the second two being estimates of a similar decade but under 1.5 and 2 °C conditions a century in the future. We use the representative concentration pathway 2.6 (RCP2.6) to provide the model boundary conditions for the 1.5 °C scenario, and a weighted combination of RCP2.6 and RCP4.5 for the 2 °C scenario. </jats:p

EZH2 is a sensitive marker of malignancy in salivary gland tumors

BACKGROUND: The immunohistochemical detection of Enhancer of zeste homologue 2 (EZH2) proved to be a useful tool to recognize the malignant nature of tumors in a wide variety of neoplasms. The histological diagnostics of salivary gland tumors is a challenging task, and a reliable marker of malignancy would be extremely helpful. METHODS: EZH2 expression was investigated in 54 malignant and 40 benign salivary gland tumors of various histological types by standard immunohistochemistry. RESULTS: The majority (n = 52) of the malignant tumors stained positively, while all the investigated benign tumors were negative for EZH2. CONCLUSIONS: EZH2 expression in salivary gland tumors, similarly to the tumors of other organs is not characteristic for any tumor type, but is a solid marker of the malignant nature of the tumors

Cytokeratin 13, Cytokeratin 17, and Ki-67 Expression in Human Acquired Cholesteatoma and Their Correlation With Its Destructive Capacity

Objectives Cholesteatoma is a nonneoplastic destructive lesion of the temporal bone with debated pathogenesis and bone resorptive mechanism. Both molecular and cellular events chiefly master its activity. Continued research is necessary to clarify factors related to its aggressiveness. We aimed to investigate the expression of Ki-67, cytokeratin 13 (CK13) and cytokeratin 17 (CK17) in acquired nonrecurrent human cholesteatoma and correlate them with its bone destructive capacity. Methods A prospective quantitative immunohistochemical study was carried out using fresh acquired cholesteatoma tissues (n=19), collected during cholesteatoma surgery. Deep meatal skin tissues from the same patients were used as control (n=8). Cholesteatoma patients were divided into 2 groups and compared (invasive and noninvasive) according to a grading score for bone resorption based upon clinical, radiologic and intraoperative findings. To our knowledge, the role of CK17 in cholesteatoma aggressiveness was first investigated in this paper. Results Both Ki-67 and CK17 were significantly overexpressed in cholesteatoma than control tissues (P<0.001 for both Ki-67 and CK17). In addition, Ki-67 and CK17 were significantly higher in the invasive group than noninvasive group of cholesteatoma (P=0.029, P=0.033, respectively). Furthermore, Ki-67 and CK17 showed a moderate positive correlation with bone erosion scores (r=0.547, P=0.015 and r=0.588, P=0.008, respectively). In terms of CK13, no significant difference was found between cholesteatoma and skin (P=0.766). Conclusion Both Ki-67 and CK17 were overexpressed in cholesteatoma tissue and positively correlated with bone resorption activity. The concept that Ki-67 can be a predictor for aggressiveness of cholesteatoma was supported. In addition, this is the first study demonstrating CK17 as a favoring marker in the aggressiveness of acquired cholesteatoma

A comparison of bioclimatic conditions on Franz Josef Land (the Arctic) between the turn of the nineteenth to twentieth century and present day

The paper presents the variability of meteorological conditions: air temperature, wind speed and relative air humidity; and biometeorological indices: wind chill temperature, predicted clothing insulation and accepted level of physical activity on Franz Josef Land (in Teplitz Bay and Calm Bay) in the years 1899–1931. It employs meteorological measurements taken during four scientific expeditions to the study area. The analysis mainly covered the period October–April, for which the most complete data set is available. For that period of the year, which includes the part of the year with the Franz Josef Land’s coldest air temperatures, the range and nature of changes in meteorological and biometeorological conditions between historical periods and the modern period (1981–2010) were studied. The data analysis revealed that during the three oldest expeditions (which took place in the years 1899–1914), the biometeorological conditions in the study area were more harsh to humans than in the modern period (1981–2010) or similarly harsh. In contrast, during the 1930/1931 expedition, which represents the Early Twentieth CenturyWarming (ETCW), conditions were clearly more favourable (including predicted clothing insulation being 0.3 clo lower and 4.0 °C higher wind chill temperature than conditions observed nowadays)