Mitigation Scenarios and Pathways

 ©Henrike Doebert / Climate Analytics
©Henrike Doebert / Climate Analytics

We explore the greenhouse-gas emission reductions necessary to achieve long-term global climate goals, such as holding warming below 1.5 and 2°C warming relative to pre-industrial levels. Analysing emissions scenarios from energy-economic models and other sources with coupled carbon-cycle/climate models leads to globally “allowed” ranges of emissions for different greenhouse gases, air pollutants and sectors, as well as associated time- and pathway-dependent mitigation costs and technology portfolios.


Together with the Australian Conservation Foundation, we have been analysing Australia’s emissions profile and policies. This factsheet focuses on Australia’s vehicle fleet and outlines how it compares with other countries, breaks down the main sources of vehicle emissions and evaluates whether there are policies in place to decarbonise the sector.  
Germany needs to phase coal out of its electricity sector by 2030 to meet its obligations under the Paris Agreement. This is earlier than the dates discussed so far by the Coal Commission, a body established to come up with a coal exit plan by the end of 2018. If Germany follows the Paris Agreement compatible pathway we propose here, it can also make significant steps towards meeting its 2020 emission reduction targets – something seen as impossible at the moment. Under a planned and structured coal phase out, energy security and reliability of electricity supply is not expected to be a major concern and will be manageable. As well as reduced health impacts, a coal exit from electricity generation by 2030 in Germany will bring added benefits in job creation, helping to smooth the transition to a zero-carbon energy system.  
Limiting global warming to 1.5 or 2.0°C requires strong mitigation of anthropogenic greenhouse gas (GHG) emissions. Concurrently, emissions of anthropogenic aerosols will decline, due to coemission with GHG, and measures to improve air quality. However, the combined climate effect of GHG and aerosol emissions over the industrial era is poorly constrained. This study shows the climate impacts from removing present-day anthropogenic aerosol emissions and compares them to the impacts from moderate GHG-dominated global warming.