On January 21, 98 U.S. senators voted to affirm that “climate change is real and not a hoax.”  But the media should not misconstrue that vote as evidence that the Republican-led Senate is now seeing eye-to-eye with scientists on the issue. Moments later, 49 senators voted to deny that “human activity significantly contributes to climate change” - the position held by the vast majority of climate scientists.

Climate scientists say that human activity is not only a “significant” cause of climate change; they say it's the primary cause. According to the latest report by the United Nations' Intergovernmental Panel on Climate Change (IPCC), “It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.” The IPCC defines “extremely likely” as having 95-100% probability.  NASA similarly notes: “Most climate scientists agree the main cause of the current global warming trend is human expansion of the 'greenhouse effect' -- warming that results when the atmosphere traps heat radiating from Earth toward space.”

But some Senators who deny the science may be hoping the media won't call them out on a sleight of hand in which they vote to acknowledge that “climate change is real” while continuing to maintain that it is only happening because of natural causes. This is akin to conservative media pundits and other climate science deniers who frequently declare that “the climate is always changing.”

When it comes to discussing climate change, the issue of causation is central. It's impossible to have a debate about how to address climate change without first agreeing that human activity -- specifically the burning of fossil fuels -- is causing it. Climate scientists settled that question a long time ago, but the debate continues to play out in the Senate, a point that should not get lost in media coverage of the Senate's acknowledgement that “climate change is real.”