The Canadian federal and Ontario provincial governments’ 2025 policy decisions were focused on affordability and competitiveness-focused responses to trade pressure and rising electricity demands. The influence of this on Ontario’s climate can be seen in all of the climate adjacent policy decisions made regarding energy, infrastructure, land-use and fiscal decisions that either increased the pace of low-carbon buildout or weakened environmental guardrails and climate accountability, depending on the file.
At the provincial level, one of the most environment-adjacent legislative changes came on June 5 when Bill 5, Protect Ontario by Unleashing Our Economy Act, 2025, received Royal Assent and created new tools to speed up selected projects. The Ontario government pitched the Bill as a way to “cut red tape,” “streamline approvals” and accelerate critical minerals development.
A central mechanism in Bill 5 was the Special Economic Zones Act, 2025, which allows Cabinet to designate zones, projects and proponents and then exempt or modify the application of specified provincial rules for those projects, alongside provisions that can extinguish certain causes of action.
First Nations leadership organizations and environmental groups publicly opposed Bill 5, describing that it would weaken environmental protections and limit opportunities for consultation and consent, particularly in treaty territories and areas linked to mining development. Reporting on the government’s subsequent draft approach to special economic zones noted Indigenous requests for accountability and transparency measures, which the province did not adopt in its draft consultation materials.
Bill 5 also replaced Ontario’s prior species law architecture by enacting the Species Conservation Act, 2025 and repealing the Endangered Species Act, 2007, among other related changes.
In the fall of 2025, Ontario posted the core implementation package for public comment through the Environmental Registry, including ERO 025-0909 and related guidance, prompting responses from numerous environmental groups.
The Canadian Environmental Law Association (CELA) filed submissions criticizing aspects of the proposed regulatory/guidance approach under the new Act.
Ontario Nature published joint/coalition material objecting to the proposal package, arguing that it would weaken protections for biodiversity and species-at-risk.
NFU-Ontario similarly argued that allowing the proposal would further undermine progress on Ontario biodiversity and imperil vulnerable species.
The Ontario Federation of Agriculture urged the province to adopt a clear, science-based and practical regulatory framework with transparent criteria and compliance supports for farmers.
On the electricity system, Ontario’s 2025 policy activity mixed long-lead infrastructure planning with attempts to re-tune regulatory mandates. The province introduced Bill 40, Protect Ontario by Securing Affordable Energy for Generations Act, 2025 to amend core energy statutes. External legal summaries characterized the Bill as formalizing “economic growth” as an objective in electricity-sector governance and adding new powers relevant to large loads such as data centres.
Ontario’s system planner, the IESO, launched the first window of its LT2 competitive procurement on July 3, targeting three TWh of energy and 600 MW of capacity. The Renewables Association described this first window as seeking new energy resources, such as wind or solar, and new capacity resources such as storage, arguing renewables are a low-cost, quickly deployable option for Ontario’s growing demand.
The IESO’s 2025 Annual Planning Outlook framed grid expansion partly around enabling a more decarbonized system over time while acknowledging near-term reliability constraints and discussed planning considerations including reduced reliance on existing local natural-gas generation in the GTA and transmission expansion to enable future low-carbon supply, such as SMRs.
Nuclear policy decisions were another major 2025 climate-relevant thread because they affect Ontario’s long-run electricity emissions profile. Federally, the Canadian Nuclear Safety Commission issued a construction licence on April 4 to Ontario Power Generation (OPG) to construct one BWRX-300 SMR at the Darlington New Nuclear Project site. Ontario also approved OPG’s plan to begin construction steps for the first of four SMRs at Darlington earlier in 2025, as summarized in legal/sector reporting.
Ontario’s most explicit 2025 change to climate accountability rules arrived through Bill 68, Plan to Protect Ontario Act (Budget Measures), 2025 (No.2), which received Royal Assent in late November and, among other items, repealed sections of the Cap and Trade Cancellation Act, 2018 that required Ontario to establish greenhouse gas reduction targets and to prepare and report on a climate plan.
Ecojustice, representing youth litigants in the Mathur climate case, condemned those legislative changes as stripping away climate obligations shortly before a landmark hearing.
Journalistic coverage of the change also reported criticism that the amendments were buried in budget legislation and not posted for public consultation on Ontario’s Environmental Registry, with Greenpeace Canada’s legal counsel quoted raising accountability concerns.
Oversight institutions also weighed in on Ontario’s trajectory in 2025. The Ontario Auditor General reported that Ontario is projected to miss its 2030 emissions target by at least 3.5 Mt. They also reported that the Ministry of the Environment’s January 2025 projection likely overestimated emissions reductions expected from initiatives across sectors.
Federally, a policy shift with immediate impacts for Ontarians was the end of the consumer carbon price effective Apr. 1. Reporting on the change noted that Conservatives had long campaigned against the consumer carbon tax and that industry groups like the Canadian Fuels Association expected noticeable pump-price reductions and consumer savings.
Ottawa also stated that, after removing the consumer fuel charge, federal carbon pricing would focus on industrial pricing systems, and CRA guidance reflected the end of fuel-charge filing requirements for registrants.
In late November, Prime Minister Mark Carney reached an energy deal with Alberta that included scrapping certain clean-electricity rules. Reuters reported that the deal was praised by oil industry leadership and criticized by environmentalists and by the Pembina Institute in a statement.
International rules with Ontario spillovers were most visible through trade and shipping. The EU Carbon Border Adjustment Mechanism (CBAM) remained in its transitional phase through 2025 ahead of the definitive regime to be enacted in 2026.
In shipping, the International Maritime Organization (IMO) announced approval in April of draft net-zero regulations combining emissions limits and a pricing mechanism, and Reuters reported that October negotiations over the shipping emissions deal sharpened geopolitical disagreements — including U.S. opposition — around global maritime carbon pricing.
Overall, Ontario’s 2025 policy activity is described by the provincial, federal and international governments as environment-adjacent reforms, from critical minerals to conservation governance, as red-tape reduction and service-delivery modernization. In response, First Nations organizations and multiple environmental-law and nature groups have contested the same reforms as weakening environmental protections and undermining consultation, biodiversity safeguards, or climate accountability.