In a new article (subscription only, but link here will take you to a pre-edited version on Professor Anderson’s home page) published in the journal Nature Geoscience, Kevin Anderson of Tyndall Centre for Climate Change Research at the University of Manchester, argues that many of the recent scenarios for limiting temperatures to 2C or below are far too insouciant about the challenges ahead. Anderson contends that such “up-beat — and largely uncontested — headlines . . . are delivered through unrealistically early peaks in global emissions, or through the large-scale rollout of speculative technologies intended to remove CO2 from the atmosphere …”

By contrast, Anderson contends that the carbon budgets consistent with a 2C scenario requires “profound and immediate changes to the consumption and production of energy.” Among Anderson’s conclusions:

1. The IPCC’s 1000 Gt cumulative carbon budget (for having a 66% chance or better of avoiding passing the 2C threshold) requires cessation of all carbon emissions from energy systems by 2050, five decades earlier than projected by the IPCC in its 5th Synthesis Report;
2. Of 400 IPCC scenarios that have 50% chance or more of keeping temperatures below 2C, a whopping 344 require large-scale deployment of so-called negative emissions technologies (poster’s note: these include technologies such as Direct Air Capture and Bioenergy and Carbon Capture and Sequestration);
3. Limiting emissions to 1000 GtCO2, with energy production alone chewing up 140 GtCO2 of this budget from 2011 to 2014 alone (overall a fifth of the budget has been emitted in four years), “suggests a profoundly more challenging timeframe and rate of mitigation than that typically asserted by many within the scientific community;”
   1. To avoid exceeding the remaining 650 GtCO2 in the budget would require ratcheting up emissions reduction rates to 10% annually by 2025, continuing this rate to virtual elimination of carbon dioxide by 2050. This would most likely exclude the use of fossil fuels in the post-2050 period, even with deployment of carbon capture and storage, unless its life cycle carbon emissions could be reduced by an order of magnitude;
4. Given the need to avoid further imperiling the welfare of the global poor, developing countries should need to reduce carbon intensity by approximately 13% annually, higher still for the wealthiest developed countries.

Anderson’s piece could be an excellent reading for a module on long-term responses to climate change and what it will mean to reach the overarching objectives of the Paris Agreement. Among the questions that would be ripe for class discussion:

1. What would be the policy implications of seeking to meet the more ambitious objective under Paris of limiting temperature increases to 1.5C above pre-industrial levels?;
2. Anderson portrays negative emissions options as “speculative” or a deus ex machina; do you agree? Assuming that negative technologies can help to remove carbon from the atmosphere, are there any downsides to this approach?;
3. What are some of the measures that could be taken to effectuate the radical transformation of the world’s economy that could meet the objective of limiting temperatures to 2C?