Bipolar volcanic synchronization of abrupt climate change in Greenland and Antarctic ice cores during the last glacial period Climate of the Past DOI 10.5194/cp-16-1565-2020 8 September 2020 We identify signatures of large bipolar volcanic eruptions in Greenland and Antarctic ice cores during the last glacial period, which allows for a precise temporal alignment of the ice cores. Thereby the exact timing of unexplained, abrupt climatic changes occurring during the last glacial period can be determined in a global context. The study thus provides a step towards a full understanding of elements of the climate system that may also play an important role in the future. Read more
ESD Ideas: Global climate response scenarios for IPCC assessments Earth System Dynamics DOI 10.5194/esd-11-751-2020 8 September 2020 Policy making on climate change routinely employs socioeconomic scenarios to sample the uncertainty in future forcing of the climate system, but the Intergovernmental Panel on Climate Change has not employed similar discrete scenarios to sample the uncertainty in the global climate response. Here, we argue that to enable risk assessments and development of robust policies this gap should be addressed, and we propose a simple methodology. ESD Ideas: Global climate response scenarios for IPCC assessments">Read more
Effective radiative forcing and adjustments in CMIP6 models Atmospheric Chemistry and Physics DOI 10.5194/acp-20-9591-2020 3 September 2020 The spread in effective radiative forcing for both CO 2 and aerosols is narrower in the latest CMIP6 (Coupled Model Intercomparison Project) generation than in CMIP5. For the case of CO 2 it is likely that model radiation parameterisations have improved. Tropospheric and stratospheric radiative adjustments to the forcing behave differently for different forcing agents, and there is still significant diversity in how clouds respond to forcings, particularly for total anthropogenic forcing. Read more
Emergent constraints on transient climate response (TCR) and equilibrium climate sensitivity (ECS) from historical warming in CMIP5 and CMIP6 models Earth System Dynamics DOI 10.5194/esd-11-737-2020 3 September 2020 One of the key questions in climate science is how much more heating we will get for a given rise in carbon dioxide in the atmosphere. A new generation of models showed that this might be more than previously expected. Comparing the new models to observed temperature rise since 1970, we show that there is no need to revise the estimate upwards. Air pollution, whose effect on climate warming is poorly understood, stopped rising, allowing us to better constrain the greenhouse gas signal. TCR) and equilibrium climate sensitivity (ECS) from historical warming in CMIP5 and CMIP6 models">Read more
Open weather and climate science in the digital era Geoscience Communication DOI 10.5194/gc-3-191-2020 1 September 2020 At the 14th IEEE International eScience Conference domain specialists and data and computer scientists discussed the road towards open weather and climate science. Open science offers manifold opportunities but goes beyond sharing code and data. Besides domain-specific technical challenges, we observed that the main challenges are non-technical and impact the system of science as a whole. Read more
A global analysis of climate-relevant aerosol properties retrieved from the network of Global AtmosphereWatch (GAW) near-surface observatories Atmospheric Measurement Techniques DOI 10.5194/amt-13-4353-2020 1 September 2020 The paper establishes the fiducial reference of the GAW aerosol network providing the fully characterized value chain to the provision of four climate-relevant aerosol properties from ground-based sites. Data from almost 90 stations worldwide are reported for a reference year, 2017, providing a unique and very robust view of the variability of these variables worldwide. Current gaps in the GAW network are analysed and requirements for the Global Climate Monitoring System are proposed. GAW) near-surface observatories">Read more
Anthropogenic climate change and glacier lake outburst flood risk: local and global drivers and responsibilities for the case of lake Palcacocha, Peru Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-2175-2020 27 August 2020 There is increasing interest and need to analyze the contribution of anthropogenic climate change to negative impacts of climate change. We study the case of glacial lake Palcacocha in Peru, which poses a significant flood risk to the city of Huaraz. We found that greenhouse gas emissions; strong urbanization processes without appropriate land use planning; and social, cultural, political, and institutional factors all contribute to the existing flood risk. Read more
The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500 Geoscientific Model Development DOI 10.5194/gmd-13-3571-2020 27 August 2020 This study provides the future greenhouse gas (GHG) concentrations under the new set of so-called SSP scenarios (the successors of the IPCC SRES and previous representative concentration pathway (RCP) scenarios). The projected CO 2 concentrations range from 350 ppm for low-emission scenarios by 2150 to more than 2000 ppm under the high-emission scenarios. We also provide concentrations, latitudinal gradients, and seasonality for most of the other 42 considered GHGs. SSP) greenhouse gas concentrations and their extensions to 2500">Read more
Rainfall intensification increases the contribution of rewetting pulses tosoil heterotrophic respiration Biogeosciences DOI 10.5194/bg-17-4007-2020 25 August 2020 Carbon dioxide is produced by soil microbes through respiration, which is particularly fast when soils are moistened by rain. Will respiration increase with future more intense rains and longer dry spells? With a mathematical model, we show that wetter conditions increase respiration. In contrast, if rainfall totals stay the same, but rain comes all at once after long dry spells, the average respiration will not change, but the contribution of the respiration bursts after rain will increase. Read more
An overview of and issues with sky radiometer technology and SKYNET Atmospheric Measurement Techniques DOI 10.5194/amt-13-4195-2020 25 August 2020 This paper overviews the progress in sky radiometer technology and the development of the network called SKYNET. It is found that the technology has produced useful on-site calibration methods, retrieval algorithms, and data analyses from sky radiometer observations of aerosol, cloud, water vapor, and ozone. The paper also discusses current issues of SKYNET to provide better information for the community. SKYNET">Read more
