Some back of the envelope economics from a poor salesman.
September 1st 2024, before Trump was elected and before any tariffs had been discussed Alberta Oil (WCS) was selling in the States at 55.90 USD per barrel.
The WCS was displacing the homegrown WTI which the US was selling on the open market at 70.24 USD per barrel allowing the States to pocket 14.34 USD per barrel as gross revenue.
At that time the Canadian Dollar was trading at 74 US Cents on the Canadian Dollar.
At that price and exchange rate Alberta was pocketing 75.54 CAD per barrel.
And the Alberta budget was looking pretty healthy.
...
Changes.
...
Today WCS is selling in the States at 61.42 USD per barrel. The price the US refineries are paying has risen 10%.
WTI is selling for 72.53 USD per barrel giving allowing the US to pocket 11.11 USD per barrel as gross revenue. The revenue has fallen 22%.
Today the Canadian Dollar is trading at 69 US Cents on the Canadian Dollar. A 7% reduction in the value of the Canadian Dollar.
At today's price and exchange rate Alberta is pocketing 89.01 CAD per barrel. An 18% increase in the revenue stream to Alberta.
And the Alberta budget is looking even healthier.
...
Future with a 10% tariff added.
With a 10% tariff on top of today's price the US refineries will be paying 67.56 USD per barrel.
Assuming that WTI is still selling at today's price of 72.53 USD (a poor assumption) then the US will only be pocketing 4.97 USD per barrel
Alberta will still be pocketing 89.01 CAD per barrel.
Is it still worth the US refineries' effort? Possibly not.
...
Solution
Alberta sells oil at 75.54 CAD per barrel, its Sept 1 2024 price. With the weaker dollar and the reduced price then the US refineries will be paying 57.34 USD per barrel for the WCS and be selling WTI at 72.53 USD resulting in a revenue stream of 15.19 USD per barrel.
The refineries will actually be making 85 Cents a barrel more than they were before the tariff was imposed and Alberta is making exactly the same.
...
These types of changes are well within the "natural" flux the markets experience. There is nothing world ending about them.