Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

What would it take to limit climate change to 1.5°C?

21.05.2015

A new study analyzes the required climate policy actions and targets in order to limit future global temperature rise to less than 1.5 degrees Celsius by 2100. This level is supported by more than 100 countries worldwide, including those most vulnerable to climate change, as a safer goal than the currently agreed international aim of 2 degrees Celsius – an aim which would already imply substantial greenhouse-gas reductions. Hence the interest for scrutinizing the very low end of greenhouse-gas stabilization scenarios.

Limiting temperature rise by 2100 to less than 1.5 degrees Celsius is feasible, at least from a purely technological standpoint, according to the study published in the journal Nature Climate Change by researchers at the International Institute for Applied Systems Analysis (IIASA), the Potsdam Institute for Climate Impact Research (PIK), and others.

The new study examines scenarios for the energy, economy, and environment that are consistent with limiting climate change to 1.5 degrees Celsius above pre-industrial levels, and compares them to scenarios for limiting climate change to 2 degrees Celsius.

“Actions for returning global warming to below 1.5 degrees Celsius by 2100 are in many ways similar to those limiting warming to below 2 degrees Celsius,” says IIASA researcher Joeri Rogelj, one of the lead authors of the study. “However, the more ambitious 1.5 degrees Celsius goal leaves no space to further delay global mitigation action and emission reductions need to scale up swiftly in the next decades.”

The authors note, however, that the economic, political, and technological requirements to meet even the 2 degrees Celsius target are substantial. In the run-up to climate negotiations in December 2015, such information is important for policymakers considering long-term goals and steps to achieve these goals.

Key elements: accelerated energy efficiency gains and CO2 removal

The study identifies key elements that would need to be in place in order to reach the 1.5 degrees Celsius target by 2100. One fundamental feature is the tight constraint on future carbon emissions.

“In 1.5 degrees Celsius scenarios, the remaining carbon budget for the 21st century is reduced to almost half compared to 2 degrees Celsius scenarios,” explains PIK researcher Gunnar Luderer, who co-led the study. “As a consequence, deeper emissions cuts are required from all sectors, and global carbon neutrality would need to be reached 10-20 years earlier than projected for 2 degrees Celsius scenarios.”

Faster improvements in energy efficiency also emerge as a key enabling factor for the 1.5 degrees Celsius target. In addition, all the scenarios show that at some point in this century, carbon emissions would have to become negative at a global scale. That means that significant amounts of CO2 would need to be actively removed from the atmosphere. This could occur through technological solutions such as bioenergy use combined with carbon capture and storage - a technology that remains untested on a large scale, increases the pressure on food supply systems and in some cases lacks social acceptance - or through efforts to grow more forests, sequestering carbon in tree trunks and branches. Afforestation, however, just like bioenergy plantations, would have to be carefully balanced against land use requirements for food production.

Overshooting the limit - and declining to 2100

In contrast to many scenarios examined in recent research, which set 2 degrees Celsius as the absolute limit and do not allow temperature to overshoot the target, the current set of scenarios looks at a long term goal, and what would need to happen to get temperature back down to that level by 2100.

“Basically all our 1.5 degrees Celsius scenarios first exceed the 1.5 degrees Celsius temperature threshold somewhere in mid-century,” explains Rogelj, “before declining to 2100 and beyond as more and more carbon dioxide is actively removed from the atmosphere by specialized technologies.”

The recent IPCC fifth assessment report did not describe in detail the critical needs for how to limit warming to below 1.5 degrees Celsius as the scenarios available to them did not allow for an in-depth analysis. Yet over 100 countries worldwide - over half of the countries in the United Nations Framework Convention on Climate Change (UNFCCC), including the Alliance of Small Island States (AOSIS) and the Least-Developed Countries (LDCs) - have declared their support for a 1.5 degrees Celsius target on climate change. The target itself is also up for debate at the upcoming climate negotiations. This new study fills this gap.

The authors make clear that an increase of international efforts to curb greenhouse gases is imperative to keep the 1.5 degrees Celsius target achievable.

“The 1.5 degrees Celsius target leaves very little leeway,” says Luderer. “Any imperfections - be it a further delay of meaningful policy action, or a failure to achieve negative emissions at large scale - will make the 1.5 degrees Celsius target unattainable during this century.”

Article: Rogelj, J., Luderer, G., Pietzcker, R.C., Kriegler, E., Schaeffer, M., Krey, V., Riahi, K. (2015): Energy system transformations for limiting end-of-century warming to below 1.5°C. Nature Climate Change [DOI: 10.1038/NCLIMATE2572]

Weblink to the article once it is published: http://dx.doi.org/10.1038/NCLIMATE2572

For further information please contact:

Jonas Viering, Sarah Messina, Mareike Schodder
PIK press office
Phone: +49 331 288 25 07
E-Mail: press@pik-potsdam.de
Twitter: @PIK_Climate

Katherine Leitzell
IIASA Press Office
Phone: +43 2236 807 316
Mob: +43 676 83 807 316
E-Mail: leitzell@iiasa.ac.at

Jonas Viering | Potsdam-Institut für Klimafolgenforschung
Further information:
http://www.pik-potsdam.de

More articles from Earth Sciences:

nachricht New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz

nachricht Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>