He later graduated from McGill University and received a diploma from Vanier College, and began working with the Conservation Council of New Brunswick.

In 1989, Coon stated that "the mere possibility of a serious accident with the reactor or radioactive waste stored at the site is too great a risk to justify expansion of nuclear power in the province," further adding that "It's one of the newest and it cost us a billion dollars – it better work.

[27] During his running for leadership of the New Brunswick Greens, Coon proposed to serve as leader full-time;[8] at the time he was the conservation council's executive director.

[29] In 2013, following the opening of a Starbucks in Moncton which only had English menus, Coon advocated for sign legislation similar to that enforced in the neighbouring, largely-Francophone city of Dieppe, which would, due to New Brunswick's official bilingual status, require for international businesses to include both English and French signage.

[30] In March 2014, Coon demanded for the provincial government under David Alward to publicly release a contract they signed with J. D. Irving to "guarantee wood supply from Crown land."

He criticized the agreement, which allowed for 21% more softwood to be cut, and argued that "New Brunswickers and First Nations have a right to know what David Alward has signed away to the Irvings."

"[31] In May 2014, Coon criticized the provincial government's proposal, through the Department of Natural Resources, to extend the moose hunting season deadline, calling it "completely political."

Arguing that the proposal prioritized efforts to garner votes over environmental protection, Coon stated that "politicians can't buy people's votes with a bottle of rum anymore and they can't afford to buy them with tax cuts so what are they left with?"

[32] During the 2014 provincial election, Coon campaigned for the newly created seat of Fredericton South in the Legislative Assembly; his campaign was supported by a number of former NDP members, including former candidate Penny Ericson and former leader Allison Brewer, who said that he "offers a unique perspective to politics.

[37] Coon won the seat with 31% of the vote against three other candidates, including Craig Leonard, the previous Energy Minister for the Progressive Conservatives.

[38] Since his election in 2014, Coon has introduced private member's bills aimed at increasing local food security and expanding local agriculture, creating jobs in energy efficient building renovations and renewable energy, lowering the voting age, protecting citizens against frivolous lawsuits.

He has championed improving access to both mental and primary health care, alleviating poverty, the provision of midwifery services, climate action, and forest management that is socially and ecologically sound.

[40] During his political career, Coon has advocated for the government to fulfill calls to action made by the Truth and Reconciliation Commission.

[41] In 2016, he called for government funding towards mandatory public school programs which would introduce the endangered Maliseet language to curriculums, which he had been advocating for since 2010.

[42] Later that year, Coon spoke with University of New Brunswick director David Perley, which led to him introducing a private member's bill focused on improving the public school curriculum on indigenous education.