Paris conference – in the best case – cannot achieve more than 0.17ºC impact on climate

Bjorn Lomborg has a new survey paper out in Global Policy

Impact of Current Climate Proposals, Bjorn Lomborg, Global Policy, Article first published online: 9 NOV 2015, DOI: 10.1111/1758-5899.12295

Lomborg’s survey and calculations only reinforce my view that the coming Paris climate conference is almost completely irrelevant to climate. So called climate policy is fundamentally flawed since the climate effect of the actions emanating from the policies cannot be measured, predicted or monitored.

Paris is essentially about wealth redistribution and that too based on ineffective tools. In fact, the primary tool, which is the reduction of carbon dioxide emissions, is not even known for certain to be a tool. Lomborg shows that assuming that climate models are correct in their assumptions of the impact of CO2 (which they are not), and assuming that all promises are binding (which they will not be), and assuming that all countries live up to their “promises” (which they won’t), then by 2100 the impact on climate could, at worst be 0.048ºC, and at best, be all of 0.17ºC.


This article investigates the temperature reduction impact of major climate policy proposals implemented by 2030, using the standard MAGICC climate model. Even optimistically assuming that promised emission cuts are maintained throughout the century, the impacts are generally small. The impact of the US Clean Power Plan (USCPP) is a reduction in temperature rise by 0.013°C by 2100. The full US promise for the COP21 climate conference in Paris, its so-called Intended Nationally Determined Contribution (INDC) will reduce temperature rise by 0.031°C. The EU 20-20 policy has an impact of 0.026°C, the EU INDC 0.053°C, and China INDC 0.048°C. All climate policies by the US, China, the EU and the rest of the world, implemented from the early 2000s to 2030 and sustained through the century will likely reduce global temperature rise about 0.17°C in 2100. These impact estimates are robust to different calibrations of climate sensitivity, carbon cycling and different climate scenarios. Current climate policy promises will do little to stabilize the climate and their impact will be undetectable for many decades.



Based on climate model simulations, the emission cuts that have been proposed by the US, the EU, China and the RoW will reduce temperature increases by the end of the century, but almost all of the expected warming will still take place by 2100.

Because the climate policy impacts from individual countries are almost additive, they can be almost perfectly partitioned as is evidenced in Table 1. This shows that in the optimistic case, the EU and China each reduce mean global temperature by 2100 of about 0.05°C, and the US and the RoW each reducing a bit more than 0.03°C.

Table 1. Impact of climate policies, optimistic and pessimistic, for RCP8.5, using MAGICC, summary of finds described throughout the text
Change in temperature
°C year 2100 Pessimistic Optimistic
US INDC 0.008 0.031
US CPP 0.004 0.013
EU INDC 0.017 0.053
EU 2020 0.007 0.026
China INDC 0.014 0.048
RoW INDC 0.009 0.036
Global INDCs 0.048 0.170

As Wigley (1998) found for the Kyoto Protocol, the emissions reductions promised until 2030 will do little to stabilize the climate and their impact will be undetectable for many decades. This clearly indicates that if we want to reduce climate impacts significantly, we will have to find better ways than the ones currently proposed.

There will be much spin after Paris. Whether agreement is reached or not, and whether promises made are binding or not, it will surely be spun to seem to be a resounding success.

But it will all be, in the most optimistic case, for achieving all of a 0.17ºC impact on climate. And based on climate models which don’t work. And on unnecessary and pointless actions for a 100 years, which will achieve nothing of their objectives, but which will make life more difficult, especially for the energy-poor.

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One Response to “Paris conference – in the best case – cannot achieve more than 0.17ºC impact on climate”

  1. La conferenza di Parigi, nel migliore dei casi, non riuscirà ad avere un impatto sul clima maggiore di 0,17°C : Attività Solare ( Solar Activity ) Says:

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