Intergovernmental Panel On Climate Change AR4 Research Articles

The evolution of 21st century sea-level projections from IPCC AR5 to AR6 and beyond

AbstractSea-level science has seen many recent developments in observations and modelling of the different contributions and the total mean sea-level change. In this overview, we discuss (1) the evolution of the Intergovernmental Panel on Climate Change (IPCC) projections, (2) how the projections compare to observations and (3) the outlook for further improving projections. We start by discussing how the model projections of 21st century sea-level change have changed from the IPCC AR5 report (2013) to SROCC (2019) and AR6 (2021), highlighting similarities and differences in the methodologies and comparing the global mean and regional projections. This shows that there is good agreement in the median values, but also highlights some differences. In addition, we discuss how the different reports included high-end projections. We then show how the AR5 projections (from 2007 onwards) compare against the observations and find that they are highly consistent with each other. Finally, we discuss how to further improve sea-level projections using high-resolution ocean modelling and recent vertical land motion estimates.

Evaluation of Flood and Drought Events Using AR5 Climate Change Scenarios in Indonesia

Indonesia is an archipelagic country located on the equator. The issue of climate change has become a global issue that has impacted several sectors in Indonesia recently. The presence of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) has contributed to conducting studies on flood and drought events. This review paper summarized 16 published papers that have gone through peer-review, both in the form of publications in journals and at conferences. Since the release of the IPCC AR5 to date, ten studies on flooding and six studies on drought events have been conducted. The most publications on this in 2019 were five publications. Of the various types of the Representative Concentration Pathway (RCP) scenarios used with various methods, the most widely used scenario RCPs is RCP4.5. From the climate change scenario, precipitations parameter is the main parameter that is used in assessing flood or drought events. There are studies conducted on a district / city, provincial scale, and some are even carried out on a watershed scale. The location or province that most flood studies have been carried out is in the capital of Jakarta. The results of these studies generally indicate that the incidence of floods and droughts will increase in the future. Therefore, adaptation steps are needed to deal with unfavorable conditions in the future. Moreover, as the capital city, Jakarta has been estimated that the projected flood incidence will increase. Several publications have provided steps to deal with these challenges on the positive side.

Assessment on Shoreline Retreat in Response to Sea Level Rise – Chennai Coast

Dhanalakshmi, S. and Kankara, R.S., 2020. Assessment on shoreline retreat in response to sea level rise – Chennai coast. In: Sheela Nair, L.; Prakash, T.N.; Padmalal, D., and Kumar Seelam, J. (eds.), Oceanic and Coastal Processes of the Indian Seas. Journal of Coastal Research, Special Issue No. 89, pp. 145-149. Coconut Creek (Florida), ISSN 0749-0208.In the present condition, the rise in sea level due to climate change is a serious threat for the environment. Global average sea levels are predicted as 1.8 mm/y during 1870-2009 and nearly 2.8 mm/y along the Indian Coast by Intergovernmental Panel on Climate change (IPCC). Impacts of rise in sea-level will be the loss of land in coastal areas through erosion, submergence of the coastal landscape and the threat of inundation. Shore erosion causes the shoreline to retreat and this leads to affecting the erosion zone by moving the shoreline inland. In this study, the attempt is made to demarcate the impact of sea level rise along the Chennai coast (Tamil Nadu) located along the southeast coast of India. This area experiences threat from many disasters such as storm, cyclone, flood, tsunami and long-term sea level rise. The shoreline has been extracted and using DSAS tool in ArcGIS, long-term (1990-2012, 1990-2013, 1990-2014, 1990-2015 and 1990-2016) were analyzed using Linear regression Rate and Weighted Linear Regression. 36.7% of the coast was seen with eroding condition. Overall long-term analysis trend suggest that more than 60% of the region falls in stable to low accretion. Projection of climate change-induced SLR at different RCPs (2.6, 4.5, 6, 8.5) of IPCC AR5 on different time scale (2025, 2050, 2075, 2100) for the coasts of Chennai. The values range from 7.1 cm to 36.87 cm for RCP 2.6; 7.37 cm to 49.84 cm for RCP 4.5; 7.16 cm to 51.75 cm for RCP 6; 7.38 cm to 77.88 cm for RCP 8.5. Shoreline retreat to an increase in local sea level was mapped using the Bruun Rule. Since the Bruun Rule (BR) has some limitations, the modified Bruun rule was used to analyze the inundation factor. The area of horizontal inundation is estimated as ∼1.6 km (Bruun rule) and ∼1.1 km (Modified Bruun Rule). The required data was processed using GIS environment. Since we adhere to the fact that the coastal change is not a periodical accumulation per year, but that it entraps a value of future crisis assessment and gives a literal warning about the shore to be persevered.

Flood Risk Assessment Based on Fuzzy Synthetic Evaluation Method in the Beijing-Tianjin-Hebei Metropolitan Area, China

Flooding is one of the most devastating natural events and leads to enormous and recurring loss of life, properties, and resources around the globe. With climate change and accelerating urbanization, flood disasters in China have increasingly affected the sustainable development of metropolitan areas. Risk assessment is an essential step in flood management and disaster mitigation, which provide a quantitative measure of flood risk. However, the difficulty of flood risk zoning is dealing with the uncertainty of the evaluation process and the complicated non-linear relationship between indicators and risk levels. To address this issue, a fuzzy synthetic evaluation (FSE) method based on combined weight (CW) was utilized in this paper to generate flood risk maps at a grid-scale (1 × 1 km). For the case study in the Beijing-Tianjin-Hebei metropolitan area (BTH) in China, fourteen indicators were selected to construct the flood risk assessment model based on the FSE approach integrated with ArcGIS. The research demonstrates that moderate, high, and very high risk zones are distributed in the southeast fluvial plain of the BTH area, accounting for 31.36% of the total land area. Meanwhile, low and very-low risk zones occupy 68.64% of the total land area, and are primarily located in the high plateau and mountain regions in the northwest. We analyzed the risk level of each county and proposed risk mitigation measures based on field investigations. The verified risk assessment results were spatially consistent with the historical flood disaster records and loss positions, indicating the accuracy and reliability of the risk assessment map using the FSE approach. Compared with the IPCC (Intergovernmental Panel on Climate Change) TAR (Third Assessment Report) and AR5 (Fifth Assessment Report) methods, FSE has significant advantages in handling uncertainty, complexity, and the non-linear relationship between indices and risk grades. This study provides a novel quantitative method for flood risk assessment in metropolitan areas and practical implications for urban flood management.

Sea Level Rise Scenario for 2100 A.D. in the Heritage Site of Pyrgi (Santa Severa, Italy)

Sea level rise is one of the main risk factors for the preservation of cultural heritage sites located along the coasts of the Mediterranean basin. Coastal retreat, erosion, and storm surges are posing serious threats to archaeological and historical structures built along the coastal zones of this region. In order to assess the coastal changes by the end of 2100 under the expected sea level rise of about 1 m, we need a detailed determination of the current coastline position based on high resolution Digital Surface Models (DSM). This paper focuses on the use of very high-resolution Unmanned Aerial Vehicles (UAV) imagery for the generation of ultra-high-resolution mapping of the coastal archaeological area of Pyrgi, Italy, which is located near Rome. The processing of the UAV imagery resulted in the generation of a DSM and an orthophoto with an accuracy of 1.94 cm/pixel. The integration of topographic data with two sea level rise projections in the Intergovernmental Panel on Climate Change (IPCC) AR5 2.6 and 8.5 climatic scenarios for this area of the Mediterranean are used to map sea level rise scenarios for 2050 and 2100. The effects of the Vertical Land Motion (VLM) as estimated from two nearby continuous Global Navigation Satellite System (GNSS) stations located as close as possible to the coastline are included in the analysis. Relative sea level rise projections provide values at 0.30 ± 0.15 cm by 2050 and 0.56 ± 0.22 cm by 2100 for the IPCC AR5 8.5 scenarios and at 0.13 ± 0.05 cm by 2050 and 0.17 ± 0.22 cm by 2100, for the IPCC Fifth Assessment Report (AR5) 2.6 scenario. These values of rise correspond to a potential beach loss between 12.6% and 23.5% in 2100 for Representative Concentration Pathway (RCP) 2.6 and 8.5 scenarios, respectively, while, during the highest tides, the beach will be provisionally reduced by up to 46.4%. In higher sea level positions and storm surge conditions, the expected maximum wave run up for return time of 1 and 100 years is at 3.37 m and 5.76 m, respectively, which is capable to exceed the local dune system. With these sea level rise scenarios, Pyrgi with its nearby Etruscan temples and the medieval castle of Santa Severa will be exposed to high risk of marine flooding, especially during storm surges. Our scenarios show that suitable adaptation and protection strategies are required.

Facilitating Climate-Smart Investments

The financial sector will play a key role in transitioning toward low-carbon and climate-resilient development, but financial decision makers need tailored information to guide climate-smart investment decisions. Here, we reflect upon the Sustainable Edge report and investor engagement to pilot a new approach to climate-risk assessment for companies.

Volcanic Radiative Forcing From 1979 to 2015

AbstractUsing volcanic sulfur dioxide emissions in an aerosol‐climate model, we derive a time series of global‐mean volcanic effective radiative forcing (ERF) from 1979 to 2015. For 2005–2015, we calculate a global multiannual mean volcanic ERF of −0.08 W/m2 relative to the volcanically quiescent 1999–2002 period, due to a high frequency of small‐to‐moderate‐magnitude explosive eruptions after 2004. For eruptions of large magnitude such as 1991 Mt. Pinatubo, our model‐simulated volcanic ERF, which accounts for rapid adjustments including aerosol perturbations of clouds, is less negative than that reported in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) that only accounted for stratospheric temperature adjustments. We find that, when rapid adjustments are considered, the relation between volcanic forcing and volcanic stratospheric optical depth (SAOD) is 13–21% weaker than reported in IPCC AR5 for large‐magnitude eruptions. Further, our analysis of the recurrence frequency of eruptions reveals that sulfur‐rich small‐to‐moderate‐magnitude eruptions with column heights ≥10 km occur frequently, with periods of volcanic quiescence being statistically rare. Small‐to‐moderate‐magnitude eruptions should therefore be included in climate model simulations, given the >50% chance of one or two eruptions to occur in any given year. Not all of these eruptions affect the stratospheric aerosol budget, but those that do increase the nonvolcanic background SAOD by ~0.004 on average, contributing ~50% to the total SAOD in the absence of large‐magnitude eruptions. This equates to a volcanic ERF of about −0.10 W/m2, which is about two thirds of the ERF from ozone changes induced by ozone‐depleting substances.

The FGOALS climate system model as a modeling tool for supporting climate sciences: An overview

Climate system models are useful tools for understanding the interactions among the components of the climate system and predicting/projecting future climate change. The development of climate models has been a central focus of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (LASG/IAP) since the establishment of the laboratory in 1985. In China, many pioneering component models and fully coupled models of the climate system have been developed by LASG/IAP. The fully coupled climate system developed in the recent decade is named FGOALS (Flexible Global Ocean-Atmosphere-Land System Model). In this paper, an application-oriented review of the LASG/IAP FGOALS model is presented. The improved model performances are demonstrated in the context of cloud-radiation processes, Asian monsoon, ENSO phenomena, Atlantic Meridional Overturning Circulation (AMOC) and sea ice. The FGOALS model has contributed to both CMIP5 (Coupled Model Intercomparison Project-phase 5) and IPCC (Intergovernmental Panel on Climate Change) AR5 (the Fifth Assessment Report). The release of FGOALS data has supported the publication of nearly 500 papers around the world. The results of FGOALS are cited ~106 times in the IPCC WG1 (Working Group 1) AR5. In addition to the traditional long-term simulations and projections, near-term decadal climate prediction is a new set of CMIP experiment, progress of LAGS/IAP in the development of near-term decadal prediction system is reviewed. The FGOALS model has supported many Chinese national-level research projects and contributed to the national climate change assessment report. The crucial role of FGOALS as a modeling tool for supporting climate sciences is highlighted by demonstrating the model’s performances in the simulation of the evolution of Earth’s climate from the past to the future.

Evaluation of intra‐seasonal oscillation simulations in IPCC AR5 coupled GCMs associated with the Asian summer monsoon

ABSTRACTIn this study, we systematically evaluate the intra‐seasonal oscillation (ISO) associated with the Asian summer monsoon region in coupled general circulation models (GCMs) participating in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). Results show that most of the models simulate reasonable climatological circulation patterns in boreal summer, but insufficient precipitation over the Bay of Bengal (BOB) and western North Pacific summer monsoon region. Most models underestimate the variance of 12–90‐day ISO mode but overestimate the percent variance of 12–90‐day ISO accounting for raw precipitation anomalies. There remains a wide gap between model simulations and observations in the simulations of eastward‐propagating ISO (30–80‐day), while the models perform better in the northward propagation of the 30–80‐day mode and the westward propagation of the 12–24‐day mode.In addition, mean state circulation, atmospheric internal dynamic process, air–sea interactions and model resolution have varying degrees of impacts on the ISO simulation. The local Hadley and Walker cell biases are investigated in this study, which might relate well with the precipitation bias in models. Within the similar background of vertical easterly shear, few models have the capacity to simulate the equivalent barotropic vorticity to the north of the convection centre. Furthermore, many models have difficulty in reproducing the strong air–sea interactions over the Indian Ocean and the BOB. Our results indicate that simply improving model resolution is not an effective method to obtain more reasonable propagation characteristics of the ISO, especially for eastward propagation. Therefore, further improving the capacity of the ISO simulation remains a great challenge for future development of climate system models.

Global warming projections to 2100 using simple CO2 greenhouse gas modeling and comments on CO2 climate sensitivity factor

As global climate change auspiciously transcends national boundaries, it is imperative to make effective treaties to reduce greenhouse gas (GHG) emissions (e.g., CO2 in particular) while improving energy usage efficiency. The scientific community through the Intergovernmental Panel on Climate Change (IPCC) has made reasonable anthropogenic global warming (AGW) predictions. However, the IPCC models have failed to predict the global warming pause since ca. 2000 to 2014. The 1880–2015 global temperature anomaly (GTA) can be modelled by the equation proposed in part by Loehle and Scafetta, 2011, Open Atmos. Sci. J. 5, 74–86 with the incorporation of the CO2 sensitivity factor (c) in this work: GTA=a∗cos(ω∗(y−1880)+ϕ)+c∗ln([CO2]y/[CO2]1958)+d∗(y−1958)+e where a (amplitude) = 0.15 °C, ω (angular frequency) = 2.π/58 rad y−1, ϕ (phase shift) = −0.05 rad, c (climate sensitivity factor) = 2.52 °C, y = year, d = 0.0013 °C y−1 (global warming since the Little Ice Age), [CO2] is the atmospheric CO2 concentration (in ppm), and e (constant) = −0.02 °C. The extracted model CSF (2.52 °C (CSF)) is in excellent agreement with an earlier value of 2.52 °C (Callendar, 1938, Quart. J. Roy. Meteorol. Soc. 64, 223–240 – corresponds to 283 K, a water vapor pressure of 1,000 Pa, and a [CO2] range of 100–600 ppm), but is significantly smaller than the average IPCC AR5 CSF (4.33 °C). Hence, a more reasonable CSF would be 2.52 °C based on actual GTA data in the present work modeling. From that equation, the 2100 GTA is projected to be −0.3, 0.7, and 1.8 °C under 3 representative 100.Δ[CO2]/([CO2].Δyear change scenarios of −0.5, 0.0, and 0.5%.y−1, respectively, compared to the 2015 GTA of 0.9 °C. The COP21 agreement calls for the GTA to be less than 1.4 °C (preferrably 0.9 °C) by 2100, and this can only be achieved if the increase in atmospheric CO2 level after 2015 is maintained at 0.0% per year.

FAOSTAT estimates of greenhouse gas emissions from biomass and peat fires

The Global Fire Emissions Database (GFED3) and the FAOSTAT Emissions database, containing estimates of greenhouse gas (GHG) emissions from biomass burning and peat fires, are compared. The two datasets formed the basis for several analyses in the fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5), and thus represent a critical source of information for emissions inventories at national, regional and global level. The two databases differ in their level of computational complexity in estimating emissions. While both use the same burned area information from remote sensing, estimates of available biomass are computed in GFED3 at tier 3 using a complex dynamic vegetation model, while they are computed in FAOSTAT using default, tier 1 parameters from the Intergovernmental Panel on Climate Change (IPCC). Over the analysis period 1997–2011, the two methods were found to produce very similar global GHG emissions estimates for each of the five GFED aggregated biomass fire classes: i) Savanna; ii) Woodland; iii) Forest; iv) Deforestation; v) Peatlands; with total emissions ranging 6–8 Gt CO2eq yr-1. The main differences between the two datasets were found with respect to peat fires, with FAOSTAT showing a lower 1997–1998 peak in emissions compared with GFED3, within an otherwise good agreement for the rest of the study period, when limited to the three tropical countries covered by GFED. Conversely, FAOSTAT global emissions from peat fires, including both boreal and tropical regions, were several times larger than those currently estimated by GFED3. Results show that FAOSTAT activity data and emission estimates for biomass fires offer a robust alternative to the more sophisticated GFED data, representing a valuable resource for national GHG inventory experts, especially in countries where technical and institutional constraints may limit access, generation and maintenance of more complex methodologies and data.

Present Simulation and Future Typhoon Activity Projection over Western North Pacific and Taiwan/East Coast of China in 20-km HiRAM Climate Model

A High Resolution Atmospheric Model (HiRAM) at 20-km resolution is adopted to simulate tropical storm (TS) activity over the western North Pacific (WNP) and Taiwan/East Coast of China (TWCN) at the present time (1979 - 2003) and future climate (2075 - 2099) under the Intergovernmental Panel on Climate Change (IPCC) fifth assessment report (AR5) representative concentration pathway (RCP) 8.5 scenarios. The results show that in contrast to TS simulation activities in most of the low-resolution climate models, TS activities except intensity over the WNP and TWCN region are well simulated by HiRAM at 20-km resolution. The linkage between large-scale environments and TS genesis simulated by HiRAM are dramatically superior to those in low-resolution fifth Coupled Model Intercomparison Project (CMIP5) models. During 2075 - 2099, both TS genesis numbers and TS frequency over the WNP and TWCN are projected to decrease consistent with the IPCC AR5 report. However, the rate of decrease (49%) is much greater than that projected in IPCC AR5. The decrease in TC genesis numbers under global warming is primarily attributed to the reduction in mid-level relative humidity and large-scale ascending motion, despite the warmer sea surface temperature (SST) providing more favorable conditions for TS formation. TS intensity and the maximum precipitation rate are projected to increase under global warming. At the end of the 21^(st) century, the mean precipitation rate within 200 km of TS storm center over the TWCN region is projected to increase by 54%.

Decarbonizing the Global Energy System: An Updated Summary of the IPCC Report on Mitigating Climate Change

AbstractThe third volume of the 5th Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) published in 2104 provides a comprehensive assessment of options for mitigating climate change through limiting greenhouse gas (GHG) emissions. The entire AR5 serves as the main scientific input for the 21st Conference of the Parties (COP21) to the Framework Convention on Climate Change (UNFCCC) in Paris at the end of 2015. The assessment was carried out by Working Group III (WG III) of the IPCC by taking into account literature that has been accepted for publication before October 2013. Meanwhile, important publications were released describing the technical progress made and the recent cost trends seen in the field of low carbon energy supply technologies. On the basis of a brief summary of the energy‐related content of the WG III contribution to AR5, this Essay provides an overview of the latest trends. It further describes the associated implications that should be considered while interpreting the results of IPCC AR5.

Changing Climate in the MENA Means Changing Energy Needs

The leading authority on climate change, the Intergovernmental Panel on Climate Change (IPCC) has concluded that warming of the climate system is unequivocal, and will continue for centuries. The regions in the Middle East and Northern Africa (MENA) have experienced numerous extreme climate events over the past few years including the 2009 flooding in Jeddah, Kingdom of Saudi Arabia; the 2005 dust storm in Al Asad, Iraq; water scarcity throughout the Arab MENA; and the rising sea levels on the Nile Delta coast, Egypt. A climate baseline can be developed for regions in the MENA by locating climate stations in the study area using observations made in the Global Climate Observing System (GCOS). For projections of future climate, global climate models (GCMs), mathematical equations that describe the physics, fluid motion and chemistry of the atmosphere, are the most advanced science available. The Climate Research Lab at the University of Prince Edward Island has a dataset available to researchers, called the Climate, Ocean and Atmosphere Data Exchange (COADE), that provides easy access to the output from forty global climate models used in the deliberations of the Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report (AR5) including monthly global climate model projections of future climate change for a number of climate parameters including temperature and precipitation. Over the past 50 years, climate changes in the MENA Region have led to increases in annual mean temperatures and decreases in annual total precipitation. Applying all four greenhouse gas emission futures on a base climate normal of 1981-2010 to an ensemble of forty global climate models used in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5) results in future temperature increases for the MENA Region ranging from 1.6 to 2.3 degrees Celsius, and in a range of future precipitation changes from reductions of 11 percent to increases of 36 percent by the 2050s (2041-2070). These preliminary results should assist the MENA Region in planning its energy needs and its needs for renewable energy through increasing the understanding of how climate has impacted the region in the past, and how climate will impact in the future.

Global observed long-term changes in temperature and precipitation extremes: A review of progress and limitations in IPCC assessments and beyond

Abstract The Intergovernmental Panel on Climate Change (IPCC) first attempted a global assessment of long-term changes in temperature and precipitation extremes in its Third Assessment Report in 2001. While data quality and coverage were limited, the report still concluded that heavy precipitation events had increased and that there had been, very likely, a reduction in the frequency of extreme low temperatures and increases in the frequency of extreme high temperatures. That overall assessment had changed little by the time of the IPCC Special Report on Extremes (SREX) in 2012 and the IPCC Fifth Assessment Report (AR5) in 2013, but firmer statements could be added and more regional detail was possible. Despite some substantial progress throughout the IPCC Assessments in terms of temperature and precipitation extremes analyses, there remain major gaps particularly regarding data quality and availability, our ability to monitor these events consistently and our ability to apply the complex statistical methods required. Therefore this article focuses on the substantial progress that has taken place in the last decade, in addition to reviewing the new progress since IPCC AR5 while also addressing the challenges that still lie ahead.

An updated synthesis of the observed and projected impacts of climate change on the chemical, physical and biological processes in the oceans

The 5th Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) states with very high certainty that anthropogenic emissions have caused measurable changes in the physical ocean environment. These changes are summarized with special focus on those that are predicted to have the strongest, most direct effects on ocean biological processes; namely, ocean warming and associated phenomena (including stratification and sea level rise) as well as deoxygenation and ocean acidification. The biological effects of these changes are then discussed for microbes (including phytoplankton), plants, animals, warm and cold-water corals, and ecosystems. The IPCC AR5 highlighted several areas related to both the physical and biological processes that required further research. As a rapidly developing field, there have been many pertinent studies published since the cut off dates for the AR5, which have increased our understanding of the processes at work. This study undertook an extensive review of recently published literature to update the findings of the AR5 and provide a synthesized review on the main issues facing future oceans. The level of detail provided in the AR5 and subsequent work provided a basis for constructing projections of the state of ocean ecosystems in 2100 under two the Representative Concentration Pathways RCP4.5 and 8.5. Finally the review highlights notable additions, clarifications and points of departure from AR5 provided by subsequent studies.

The Core Conclusions and Interpretation of Working Group II Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change

Intergovernmental Panel on Climate Change (IPCC) released the Working Group II contribution to the Fifth Assessment Report (WGII AR5) IPCC Climate Change 2014: Impacts, Adaptation, and Vulnerability in March 2014. This paper introduces and interprets this report, making well organization of the main conclusions, analyzing the new enlightenment to China's response to climate change. WGII AR5 focuses on the assessment and management of climate change risks. According to the latest scientific literature and evidences, this report elaborates climate change's broader impacts on water resource, food production, and other natural and human social systems since 2007 IPCC Fourth Assessment Report (AR4). Via the assessment of different areas, regions, and key risks in the future, the report indicates the risk level of climate change faced with the globe under different temperature rise; aiming at risk management, the report emphasizes the significance of promoting and establishing the sustainable development society with recovery capacity through adaptation and mitigation of climate change. As an important scientific basis for international community to recognize and cope with climate change, the publication of IPCC AR5 one after another will have a significant influence on Durban Platform negotiations on post-2020 international climate regime which have been in a difficult stage, and the 2014 United Nations climate change summit [IPCC. 2014. Climate Change 2014: Impact Adaptation, and Vulnerability. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. United Kingdom and New York, NY, USA: Cambridge University Press].

Sea‐level scenarios for evaluating coastal impacts

Global‐mean sea‐level rise will drive impacts and adaptation needs around the world's coasts over the 21st century and beyond. A key element in assessing these issues is the development of scenarios (or plausible futures) of local relative sea‐level rise to support impact assessment and adaptation planning. This requires combining a number of different but uncertain components of sea level which can be linked to climatic and non‐climatic (i.e., uplift/subsidence of coastal land) factors. A major concern remains about the possibility of significant contributions from the major Greenland and Antarctic ice sheets and this must be factored into the assessments, despite the uncertainty. This paper reviews the different mechanisms which contribute to sea‐level change and considers a methodology for combining the available data to create relative (or local) sea‐level rise scenarios suitable for impact and adaptation assessments across a range of sophistication of analysis. The methods that are developed are pragmatic and consider the different needs of impact assessment, adaptation planning, and long‐term decision making. This includes the requirements of strategic decision makers who rightly focus on low probability but high consequence changes and their consequences. Hence plausible high end sea‐level rise scenarios beyond the conventional Intergovernmental Panel on Climate Change (IPCC) range and which take into account evidence beyond that from the current generation of climate models are developed and their application discussed. Continued review and development of sea‐level scenarios is recommended, starting with assimilating the insights of the forthcoming IPCC AR5 assessment. WIREs Clim Change 2014, 5:129–150. doi: 10.1002/wcc.253This article is categorized under: Assessing Impacts of Climate Change > Scenario Development and Application

Revisiting the Indian summer monsoon–ENSO links in the IPCC AR4 projections: A cautionary outlook

The climate change experiments under the fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC), namely the twentieth century simulations (20C3M) and Special Report on Emissions Scenarios (SRES) A1B, are revisited to study whether these models can reproduce the ENSO and ENSO Modoki patterns as the two important modes from statistical linear analysis as observed. The capability of the models in simulating realistic ENSO/ENSO Modoki teleconnections with the Indian summer monsoon, and also the implications for the future are also explored. Results from the study indicate that only ~1/4th of the models from 20C3M capture either ENSO or ENSO Modoki pattern in JJAS. Of this 1/4th, only two models simulate both ENSO and ENSO Modoki as important modes. Again, out of these two, only one model simulates both ENSO and ENSO Modoki as important modes during both summer and winter.It is also shown that the two models that demonstrate ENSO Modoki as well as ENSO associated variance in both 20C3M and SRESA1B represent the links of the ISMR with ENSO reasonably in 20C3M, but indicate opposite type of impacts in SREA1B. With the limited skills of the models in reproducing the monsoon, the ENSO and ENSO Modoki, it is difficult to reconcile that the teleconnections of a tropical driver can change like that. All these indicate the challenges associated with the limitations of the models in reproducing the variability of the monsoons and ENSO flavors, not to speak of failing in capturing the potential impacts of global warming as they are expected to. More research in improving the current day simulations, improving model capacity to simulate better by improving the Green House Gases (GHG) and aerosols in the models are some of the important and immediate steps that are necessary.

Interannual variability of rainfall over the Arabian Peninsula using the IPCC AR4 Global Climate Models

ABSTRACTThe interannual rainfall variability derived from the 22 Global Climate Model (GCM) simulations of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) for the duration 1979–2000 is analysed and compared with the gridded observed dataset over the Arabian Peninsula. The annual cycle of the rainfall derived from these models is validated for the entire Arabian Peninsula, and separately for its two sub‐regions, named northern and southern Arabian Peninsula. The spatial patterns of the rainfall and the mean sea level pressure are analysed to judge the ability of the models to simulate the mean climatology of the Peninsula. This analysis reveals that out of the 22 IPCC AR4 GCM multi‐model datasets, only one group (composed of 5 models) is relatively better than all the others in simulating the interannual variability of the wet season rainfall for the northern sub‐region, and another group (also composed of 5 models) is likewise for the dry season rainfall climatology of the southern sub‐region, compared with the gridded dataset. The above two groups of models tend to fall within one‐sigma standard deviation of the mean seasonal rainfall derived from the gridded dataset. Moreover, only one model [CCCMA‐CGCM3 (T47) from Canada] is found to be relatively better in simulating the rainfall climatology for both the wet and the dry seasons (i.e. for the northern and the southern sub‐regions) simultaneously, compared with the observed data.