Sen. Ted Cruz (R-TX) has the poorest understanding of climate science of all the 2016 presidential candidates, according to a report card prepared for the Associated Press by eight climate and biological scientists.

On a scale from zero to 100, the scientists gave Cruz a six.

“This individual understands less about science (and climate change) than the average kindergartner,” Michael Mann, a meteorology professor at Pennsylvania State University, wrote about Cruz’s comments, according to the AP. “That sort of ignorance would be dangerous in a doorman, let alone a president.”

The AP asked eight scientists chosen by professional science societies to grade the anonymous statements of Republican and Democratic candidates about climate science.

While Cruz had the worst score among Republicans, former Florida Gov. Jeb Bush appears to have the best understanding of climate science in the GOP with a score of 64.

The scientists also docked points from Sen. Bernie Sanders’ (I-VT) score for once exaggerating that “the planet that we’re going to be leaving our kids and our grandchildren may well not be habitable.”

“I would not say that the planet will become uninhabitable. Regardless of what we do, some humans will survive,” Andrew Dessler, a climate scientist at Texas A&M University, said of Sanders’ comment, according to the AP.

Here are all the candidates’ scores, courtesy of the Associated Press: