So much for the "I'm not a scientist, so I can't tell if climate change is real" excuse.

The US Congress can now go down in history as having made zero effort to stop climate change despite officially recognizing that it is happening.

On Wednesday, the Congress approved a largely symbolic amendment (introduced earlier by Democrats) to the bill that would approve the final phase of the Keystone XL pipeline. The amendment states "that climate change is real and not a hoax."

The approved amendment was one of two that were introduced that called for a vote on whether climate change was real. One of them (the one that passed) said simply that climate change was real. The other (which didn't pass) said climate change was real and caused by humans.

This is an unsurprising turn of events for a party that made headlines as recently as November when one of its members acknowledged that humans were probably contributing to climate change. Sen. James Inhofe of Oklahoma still thinks the whole thing's a hoax; he even went so far as to write a book about it.

But seeing as most Americans do recognize that human-caused climate change is actually a thing, many had retreated to a seemingly more neutral position in recent months. "I'm not a scientist," George P. Bush, son of former Florida Gov. Jeb Bush, told ABC News in October.

That excuse won't fly anymore, though — not since the Senate voted 98-1 on Wednesday evening that climate change is real.

The amendment that included that language was attached to a bill designed to approve the Keystone XL Pipeline's final phase of construction (a bill that President Obama has already vowed to veto). The first three phases of the pipeline, designed to carry oil from Alberta, Canada, to Texas, have already been completed. Many Democrats worry the pipeline could accelerate climate change by spurning Canadian oil companies to expand existing shale mining (or "fracking") operations in the region's oil sands.

Studies suggest the pipeline's real effects on global warming aren't yet clear. While the US State Department's own environmental assessment of the pipeline concluded that any impact it could have would be negligible, environmental groups including the Natural Resources Defense Council say it would worsen climate change by keeping oil prices high. By ensuring mining projects stay profitable, the Keystone would encourage future mining and, in turn, destruction of large swaths of Canadian wilderness.

Whether or not Keystone XL worsens global warming, at least this is a hopeful sign that we all now agree that climate change is real and worsened by human activity.

About 99% of climate scientists agree that climate change — as it's happened over the past several decades — is largely caused by humans. Last year was the world's warmest year on record. Of the 15 hottest years, 14 of them have occurred since the year 2000.

Perhaps we're not all scientists. But it's about time we started listening to them.