The protest group met with Councillor Denise Jeffery on November 28, three days before she officially took charge of the council for talks, which have been described as positive.
But in the letter, sent on November 29, Extinction Rebellion outlines its fierce opposition to a proposed £100m link road round Featherstone, which it says would be a "catastrophe" for the environment and "public relations disaster" for the council.
Written by the group's Pontefract co-ordinator, Dr Andrew Rollinson, the letter also claims Coun Jeffery said she was dissatisfied with the council's progress on becoming a carbon neutral organisation by 2030 - a promise it made in May.
Coun Jeffery has declined to comment on the contents of the letter, but council sources have stressed that the Featherstone link road is only a proposal in its very early stages, and is not certain to be built.
Chairing her first Cabinet meeting as leader on Tuesday, Coun Jeffery acknowledged concerns related to climate change about the road.
The outcome of a public consultation is likely to have a huge bearing on whether or not the road will be built, with one councillor suggesting it won't be built "if people don't want it".
Speaking on Tuesday, Dr Rollinson welcomed that development, and said that the meeting with the new leader had been constructive.
He said he had written the letter after reading about the link road proposals last week.
Asked about his meeting with Coun Jeffery, Dr Rollinson said: "She said she wanted to work with Extinction Rebellion on climate change and that a citizen's assembly would be set up in February. I did feel listened to.
"She said she was disappointed that nothing had been done by the council yet on climate change.
"Extinction Rebellion has got a lot of experience in how to do these things and she said she wanted our help. We left the meeting with the aim of meeting monthly to discuss it."
Dr Rollinson said it was crucial that the community is involved in reducing emissions, and reinforced Extinction Rebellion's position that no more roads should be built, to encourage people to give up their cars.
Another claim in the letter, that campaign group Client Earth has issued a legal challenge to Wakefield Council over perceived "inaction" on climate change has not yet been verified.
The letter in full, dated 29th November 2019 and released by Extinction Rebellion on Tuesday morning.
Thank you for meeting representatives of Extinction Rebellion yesterday. Something has prompted me to write to you so soon afterwards.
When I arrived home yesterday evening I read a news article from the Wakefield Express titled Plans to Build a New Link Road Round Featherstone..."
You will be aware of this as it went on to say that “Senior Wakefield councillors are set to sign off extra funding...”
In our meeting yesterday you asked for my help in guiding Wakefield Council to bring regional CO2 emissions down to net zero. You also expressed your desire and commitment to this cause when you take office as leader on 1st December.
In this capacity I must advise you that the proposal to build a link road would be an absolute catastrophe for any attempts to make Wakefield region net carbon zero, and any attempts to halt biodiversity loss in the region.
It would also be a total public relations disaster in relation to Wakefield’s declared Climate Emergency, for the sanctioning of such a project could never be reconciled with a commitment to sustainability.
I also feel it fair to advise you of Client Earth’s notice of legal challenge to Wakefield Council on climate inaction, and your own declared dissatisfaction (to me) that nothing so far has been done.
Scientifically, the phenomenon of ‘Induced Demand’ applies. This refers to the fact that making new roads always results in greater traffic levels and consequent pollution.
It is described as, "The one professional certainty that everyone thoughtful seems to acknowledge, yet almost no one is willing to act upon," particularly relevant since a third of Wakefield region’s CO2 emissions come from vehicular transport.
Secondly, there is biodiversity loss, with the proposed route cutting through mostly green space, farm and woodland, building on further loss of rural habitat due to urban sprawl, notably in Glass Houghton and Wakefield East.
The UK has lost 133 of its species since the 1970s.
I write to you at present in a personal capacity. As you know, I am however the representative of an international movement which is active in Pontefract and Wakefield.
Our members will not stand by and let this link road go unchallenged nor dramatically highlight the gross failure of Wakefield Council to act on its declared Climate Emergency.
It is a cliché, but we currently stand at the crossroads. As mentioned, on December 1 when you take over from the previous incumbent, a great opportunity exists for Wakefield Council to make a positive change in the right direction.
This is why I came to speak with you yesterday. I therefore advise you to make a clear announcement of your intent with respect to this link road venture, and to denounce it, on the basis that it is wholly incompatible with your immediate plans for a sustainable and biodiverse Wakefield region.
For my own personal information, and for the members whom I represent, I also ask if you will please respond to me by the end of today, to confirm your stance with respect to this proposed link road.
This includes specifically how you intend to vote on the proposal and what you intend to tell the press. I cannot stress enough the importance of this matter.
Local Democracy Reporting Service