Paris pledges ‘wishful thinking, not optimism’: Bjorn Lomborg

Implementing all carbon pledges would cut global temperature rises by less than 0.05C by 2030, analysis finds.

The effects of pre-Paris climate commitments.

Full implementation of all carbon-dioxide savings pledges made at the Paris climate change conference would reduce global temperature increases less than 0.05C by 2030, analysis by policy researcher Bjorn Lomborg has found. Even if the promised actions were continued for the following 70 years and there was no “CO2 leakage” to noncommitted nations, the reduction in temperature increases since before the industrial age would be just 0.17C by 2100, the peer-reviewed paper says.

Dr Lomborg’s findings are at odds with official statements and comments by UN climate chief Christiana Figueres that a Paris agreement could lead to a 2.7C rise instead of a 4C or 5C increase by 2100.

Dr Lomborg said Ms Figueres had “entirely misrepresented the world’s options”.

He said adopting pledges made before this month’s Paris conference by countries representing the vast majority of global greenhouse gas emissions would do little to stabilise the climate and any benefits would be undetectable for many decades.

Using accepted modelling and methodology, the Lomborg paper, to be published today, rates individual pledges made by major emissions nations China, the US and EU and the world combined.

Published in the journal Global Policy, the Lomborg paper said the best-case scenario for President Barack Obama’s pledges for the US, if continued for a century, was a reduction in temperature increases of 0.031C.

For China, it was 0.048C and for the EU it was 0.053C.

Australia is included in the “rest of the world” where combined policies had a maximum potential of reducing global ­temperature increases 0.036C by 2100.

The paper concluded: “If we want to reduce climate impacts significantly we will have to find better ways than the ones currently proposed.”

Dr Lomborg has been a controversial figure in the climate change debate despite accepting that rising levels of CO2 from human sources will have an ­impact on global temperatures.

Academic protests have blocked attempts to open a res­earch centre in Australia, either in Perth or Adelaide, with backing from the federal government.

Rather than rejecting climate science, Dr Lomborg’s core position has been that greater attention needs to be paid to the economics of combating climate change.

Releasing his new paper, he said negotiators in Paris were trying to tackle global warming in the same way that had failed for 30 years.

He said this included making prom­ises that were individually expensive, that would have little impact even in 100 years and that many governments would try to avoid.

“This didn’t work in Kyoto, it didn’t work in Copenhagen, it hasn’t worked in the 18 other ­climate conferences or countless more international gatherings,” Dr Lomborg said.

“The suggestion that it will make a large difference in Paris is wishful thinking.”

He said a Copenhagen Consensus on Climate project involving 27 of the world’s top climate economists and three Nobel Laureates found the best strategy would be to invest in green research and development.

“Instead of trying to make fossil fuels so expensive that no one wants them, which will never work, we should make green energy so cheap everybody will shift to it,” Dr Lomborg said.

Climate change negotiators have said the Paris pledges are a starting point.

The conference will convene on November 30.

In a statement, COP21 president Laurent Fabius, France’s Foreign Minister, said national contributions could make a difference and help avoid the worst-case scenario of global warming of 4C-5C or more.

“It confirms that it is possible to achieve a trajectory where warming is kept below 1.5C-2C by the end of the century, but this will ­require additional efforts over time,” Mr Fabius said.

“Some estimates put us on a trajectory of a 2.7C-3C increase by the end of the century.

“This confirms the importance of reaching an agreement at COP21 in Paris that will lay down the rules for periodically ­revising the national contributions upwards.”

Ms Figueres, the executive ­secretary of the UN Framework Convention on Climate Change, said a Paris agreement could lead to a 2.7C rise instead of 4C or 5C increase.

Dr Lomborg said Ms Figueres had “entirely misrepresented the world’s options”.

“The 2.7C comes from the International Energy Agency and essentially assumes that if governments do little in Paris and then right after 2030 embark on incredibly ambitious climate reductions, we could get to 2.7C,” Dr Lomborg said.

“Figueres’s own organisation estimates the Paris promises will reduce emissions by 33Gt CO2 in total. To limit rises to 2.7C, about 3000Gt CO2 would need to be ­reduced — or about 100 times more than the Paris commitments. That is not optimism, it is wishful thinking.”

The latest Lomborg paper uses the MAGICC climate model, which has been used across all five IPCC reports and was co-funded by the US Environmental Protection Agency.

Dr Lomborg said it had been run with standard parameters, and sensitivity analysis had shown that different assumptions of climate sensitivity, carbon cycle model or scenario did not substantially change the outcome.

Dr Lomborg said the paper had used the same basic methodology of climate scientist, Tom Wigley, who analysed the Kyoto Protocol in a much-cited paper in 1998.