The event is being publicised by a German-based political outfit called the European Institute for Climate and Energy (EIKE), with which all of the event’s speakers have a previous association. The think tank’s vice-president also advises Hilse.

The move to challenge the scientific consensus on climate change is relatively new to the EU, but has a storied history in the US — and there is evidence of ties to groups across the Atlantic.

EIKE is known for its annual climate conference, which is co-sponsored by the Heartland Institute, a US think-tank which has long financed projects which appear to undermine public confidence in climate science, and the US Committee for a Constructive Tomorrow (CFACT), another climate sceptic conservative organisation.

EIKE also shares an address with CFACT Europe, a group which was set up by current EIKE president Holger Thuss.

An Unearthed analysis of financial disclosure forms in the US has revealed CFACT Europe received financial support from its American namesake.

Though Heartland and CFACT have historic ties to the fossil fuel industry, transparency campaigners say it is now hard to identify the sources of their income, much of which comes from trusts and foundations which do not have to reveal the source of their donations.

A CFACT spokesperson told Unearthed the think tank takes no money directly from fossil fuel firms adding: “4% [of funding] comes from corporations, and zero of our funding comes from any major oil or fossil fuel company. 45% of our funding comes from thousands of small donors who contribute what they can to promote our message of free-market environmentalism, technology, and human and environmental progress.”

Thuss told Unearthed that CFACT Europe “no longer exists,” and that it was effectively – though not formally – rendered defunct in 2013.

‘Nazi youth’

Tuesday’s event coincides with a surge in AfD digital communication on climate matters, according to exclusive data from ISD.