The speed with which temperatures change will continue to increase over the next several decades, intensifying the impacts of climate change
An analysis of changes to the climate that occur over several decades suggests that these changes are happening faster than historical levels and are starting to speed up. The Earth is now entering a period of changing climate that will likely be faster than what’s occurred naturally over the last thousand years, according to a new paper in Nature Climate Change, committing people to live through and adapt to a warming world.
In this study, interdisciplinary scientist Steve Smith and colleagues at the Department of Energy's Pacific Northwest National Laboratory examined historical and projected changes over decades rather than centuries to determine the temperature trends that will be felt by humans alive today.
"We focused on changes over 40-year periods, which is similar to the lifetime of houses and human-built infrastructure such as buildings and roads," said lead author Smith. "In the near term, we're going to have to adapt to these changes."
See CMIP run
Overall, the Earth is getting warmer due to increasing greenhouse gases in the atmosphere that trap heat. But the rise is not smooth -- temperatures bob up and down. Although natural changes in temperature have long been studied, less well-understood is how quickly temperatures changed in the past and will change in the future over time scales relevant to society, such as over a person’s lifetime. A better grasp of how fast the climate might change could help decision-makers better prepare for its impacts.
To examine rates of change, Smith and colleagues at the Joint Global Change Research Institute, a collaboration between PNNL and the University of Maryland in College Park, turned to the Coupled Model Intercomparison Project. The CMIP combines simulations from over two-dozen climate models from around the world to compare model results.
All the CMIP models used the same data for past and future greenhouse gas concentrations, pollutant emissions, and changes to how land is used, which can emit or take in greenhouse gases. The more models in agreement, the more confidence in the results.
The team calculated how fast temperatures changed between 1850 and 1930, a period when people started keeping records but when the amount of fossil fuel gases collecting in the atmosphere was low. They compared these rates to temperatures reconstructed from natural sources of climate information, such as from tree rings, corals and ice cores, for the past 2,000 years.
Taken together, the shorter time period simulations were similar to the reconstructions over a longer time period, suggesting the models reflected reality well.
While there was little average global temperature increase in this early time period, Earth's temperature fluctuated due to natural variability. Rates of change over 40-year periods in North America and Europe rose and fell as much as 0.2 degrees Celsius per decade. The computer models and the reconstructions largely agreed on these rates of natural variability, indicating the models provide a good representation of trends over a 40-year scale.
Now versus then
Then the team performed a similar analysis using CMIP but calculated 40-year rates of change between 1971 to 2020. They found the average rate of change over North America, for example, to be about 0.3 degrees Celsius per decade, higher than can be accounted for by natural variability. The CMIP models show that, at the present time, most world regions are almost completely outside the natural range for rates of change.
The team also examined how the rates of change would be affected in possible scenarios of future emissions [link to RCP release http://www.pnl.gov/news/release.aspx?id=779]. Climate change picked up speed in the next 40 years in all cases, even in scenarios with lower rates of future greenhouse gas emissions. A scenario where greenhouse gas emissions remained high resulted in high rates of change throughout the rest of this century.
Still, the researchers can't say exactly what impact faster rising temperatures will have on the Earth and its inhabitants.
"In these climate model simulations, the world is just now starting to enter into a new place, where rates of temperature change are consistently larger than historical values over 40-year time spans," said Smith. "We need to better understand what the effects of this will be and how to prepare for them."
This work was supported by the Department of Energy Office of Science.
Reference: Steven J. Smith, James Edmonds, Corinne A Hartin, Anupriya Mundra, and Katherine Calvin. Near-term acceleration in the rate of temperature change, Nature Climate Change March 9, 2015, doi: 10.1038/nclimate2552.
The Joint Global Change Research Institute is a unique partnership formed in 2001 between the Department of Energy's Pacific Northwest National Laboratory and the University of Maryland. The PNNL staff associated with the institute is world renowned for expertise in energy conservation and understanding of the interactions between climate, energy production and use, economic activity and the environment.
Interdisciplinary teams at Pacific Northwest National Laboratory address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. Founded in 1965, PNNL employs 4,300 staff and has an annual budget of more than $1 billion. It is managed by Battelle for the U.S. Department of Energy's Office of Science. As the single largest supporter of basic research in the physical sciences in the United States, the Office of Science is working to address some of the most pressing challenges of our time. For more information on PNNL, visit the PNNL News Center, or follow PNNL on Facebook, Google+, LinkedIn and Twitter.
Mobile: (208) 520-1415
Mary Beckman | newswise
New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences