Right now, a broad coalition made up of farmers, steelworkers, tribes, rural citizens and environmentalists is mounting an effort to stop a network of pipelines designed to carry Canadian tar sands oil into the United States.

The tar sands oil carried by the pipelines is the dirtiest oil on earth. Its extraction has destroyed large swaths of boreal forest and poisoned birds in Canada, and its production creates more global warming pollution than any other type of crude oil.

The three massive pipelines – the Enbridge Alberta Clipper pipeline, the Transcanada Keystone I pipeline, and the Keystone XL pipeline—would run through Montana, North Dakota, South Dakota, Wisconsin, Illinois, Minnesota, Nebraska, Oklahoma, and Texas.

While our groups have many different reasons to oppose the pipelines, we all share one major concern: Safety.

Farmers and ranchers worry about the risk of spills, because companies like TransCanada have proposed much lower safety standards, including pipe thickness and pressure, where pipelines run through rural communities. One North Dakota firefighter said last week that his rural fire department hasn't even seen an emergency response plan for the pipelines designed to run right across his farmland.

Steelworkers have voiced concerns about the potential for corrosion from tar sands bitumen, along with lax standards for pipeline thickness and pressure, which could lead to spills.

In addition to the risk of spills, the pipelines threaten to gobble up disappearing farmland across the Midwest. And tribes say oil spills could destroy waterways, lakes, and bald eagle nesting grounds on their reservations.

The Department of State and Department of Transportation are in the process of deciding whether or not to allow these pipelines to move forward. To do so would place America's farmland and rural communities at risk. It would invite the dirtiest oil on earth into our country at a time when our nation should be investing in the kind of clean energy that will create good, sustainable jobs and help combat global warming. Building these dirty tar sands pipelines simply doesn't serve our national interest.

This is an excellent opportunity--for the State Department in particular--to show that America is a global leader in the clean energy economy, by supporting solutions like wind, solar, and efficient vehicles instead of more of the dirty energy of the past.