Here's what it'll take to limit climate change to 1.5 degree C by 2100

As per researchers, achieving a 1.5 degree Celsius world is feasible, at least from a purely technological standpoint.

International Institute for Applied Systems Analysis (IIASA), the Potsdam Institute for Climate Impact Research (PIK) and others' study examines scenarios for the energy, economy and environment that are consistent with limiting climate change to 1.5 degreeC above pre-industrial levels, and compares them to scenarios for limiting climate change to 2 degreeC.

IIASA's Joeri Rogelj said that actions for returning global warming to below 1.5 degreeC by 2100 are in many ways similar to those limiting warming to below 2 degreeC, but the more ambitious 1.5 degreeC 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 degreeC 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.

The study identifies key elements that would need to be in place in order to reach the target, like accelerated energy efficiency gains and CO2 removal.

Faster improvements in energy efficiency also emerge as a key enabling factor for the 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 other land use requirements, most notably food production.

The study is published in the journal Nature Climate Change.