The Obama Administration is currently deciding whether to approve the TransCanada Keystone XL pipeline, a new 2,000 mile pipeline which would bring nearly one million barrels a day of dirty tar sands oil from Canada to the Gulf of Mexico.

The BP Deepwater Horizon oil spill makes clear that when oil companies cut corners and operate without oversight and accountability, disaster will occur. We cannot trust that TransCanada – or any of the oil companies, for that matter – has its act together.

Tar sands is one of the dirtiest forms of oil production, emitting carbon dioxide at a rate three times higher than conventional oil, using significant amounts of water during extraction, and creating toxic lagoons in the process, which leak over a billion gallons of contaminated water each year.

President Obama has called for an end to business as usual in the government oversight prescribed to big oil. But if the TransCanada Keystone XL pipeline is approved, it will be big oil cutting corners and getting its way all over again. TransCanada has applied for a waiver from the federal government to use less steel to create a thinner pipeline that experts warn is incredibly vulnerable to leaks.

We have started to take a step forward, but Canadian tar sands oil and the Keystone XL pipeline would be two steps backwards. We can end oil dependence in a generation, but only if we resist Big Oil’s call to invest billions more in dirty fuel infrastructure.

Let’s start working for a clean transportation future. We must finally break our oil addiction. Let’s not start in a decade, when oil is dirtier and running out faster. Say no to tar sands oil!