For the first time, scientists have incorporated multiple human and natural factors into a climate projection model. They predict that increased carbon dioxide in the atmosphere, due to changes in the carbon cycle, combined with a decrease in human-produced sulphates, may cause accelerated global warming during the 21st century, as compared with simulations without these feedback effects.
Results of the study, completed by Chris D. Jones and colleagues at the Met Offices Hadley Centre for Climate Prediction and Research in Bracknell, United Kingdom, appear in the journal Geophysical Research Letters, published by the American Geophysical Union.
Previous studies have indicated that human activities, such as carbon dioxide and sulphate emissions, as well as natural factors, such as changes in solar radiation, emissions from volcanic eruptions and interactions between climate and the carbon cycle, are important mechanisms for causing climate change. No previous climate studies have, however, integrated all of these factors into a single climate experiment.
The climate-carbon cycle experiment completed by Jones and his colleagues is the first to take a more comprehensive Earth-systems approach to climate modeling. This "all-forcings experiment," or ALL, incorporates carbon dioxide emissions, non-carbon dioxide greenhouse gases, human-produced sulphate aerosol levels, the reflection of solar radiation associated with sulphate in the atmosphere (the "albedo effect"), atmospheric ozone levels, levels of solar radiation, the effects of volcanic eruptions, and climate-carbon cycle feedbacks.
Discrepancies between observed temperature trends in the 20th century and climate simulations that consider only a limited number of factors have hindered the ability of some models to predict future climate change. The ALL model was, however, able to recreate observed temperature records for the 20th century, illustrating the importance of including multiple factors in climate change projections. Also, the rise in carbon dioxide simulated by ALL more closely matches the observed carbon dioxide rise than did previous models. The researchers say that this indicates that mechanisms other than direct carbon dioxide emissions caused by human activity also contribute to the observed trend. Jones and his colleagues were also able to replicate estimates of the amount of carbon currently stored in the oceans and on land worldwide.
With regard to future climate predictions, ALL shows that predicted reductions in human sulphate emissions will cause a reduction in the cooling effect associated with sulphates in the atmosphere, or a net warming. The model predicts that the resultant warming will enhance soil respiration, meaning that the increased amounts of carbon stored in the soil during the 20th century will be released into the atmosphere, causing a faster rise in atmospheric carbon dioxide. By the end of the 21st century, the authors state, the increase in carbon dioxide and decrease of sulphates will cause a substantially higher global warming of 5.5 degrees Celsius [9.9 degrees Fahrenheit] compared with 4 degrees Celsius [7 degrees Fahrenheit] when these interactions are neglected.
The research was supported by the UK Department for the Environment, Food and Regional Affairs.
Harvey Leifert | AGU
Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft
How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology