Key findings – Intergovernmental Panel on Climate Change, Working Group III, “Mitigation of Climate Change.”
NTNU professors Edgar Hertwich and Daniel Beat Müller were among the lead authors of the WG III report “Mitigation of Climate Change”. We asked them to summarize what they considered to be the most important findings of the report, released 13 April 2014. Here is what they said:
• Greenhouse gas concentrations have risen at an unprecedented rate over the last 10 years, mainly because of the construction of coal-fired power plants in emerging economies, such as China.
• The steep increase in greenhouse gas emissions puts the world at the upper end – the worst case – for previous emissions scenarios published by the IPCC.
• Alternative technologies are available, and becoming more and more affordable. We can cut carbon emissions using wind power, solar heat and power, highly efficient building shells, and electric vehicles.
• Some – but not enough – climate policies have been implemented on national, regional and local levels. They will not halt the global rise in emissions, but have given policymakers experience with programmes such as emissions trading, carbon taxes, technology standards, and market penetration programmes.
• The next decade can’t be like the last decade. In fact, we have to stop CO2 emissions from fossil fuel combustion and industrial processes by the end of this century if we want to limit global average temperature increases to 2 or even 3 degrees.
• If we keep increasing our CO2 emissions over the next decade we will overshoot the 2 degree C target.
• Overshooting is risky and will be expensive. If we overshoot, the world would have to deploy expensive, unproven technologies as early as 2070 to remove CO2 from the atmosphere.
• A cool planet can mean cleaner air. Replacing fossil fuels with energy efficiency and a range of renewable and nuclear energy technologies, if properly chosen, may lead to a substantial reduction of pollution and associated health and ecological impacts.
• The world has gotten more efficient over the past decades, but not enough to cut emissions to the levels that are needed. We need to change the way we design cities to cut transportation and construction emissions and to allow for urban mining of recyclable materials, among other approaches.
Edgar Hertwich, Daniel Müller, March 2014
Also read: Cool climate – clean planet