Many people have heard the claim that 97 percent of scientists believe in global warming. Politicians from President Barack Obama to former Secretary of State John Kerry have cited the statistic.


But is it true? 


The Heartland Institute, a Chicago-based think tank and national nonprofit organization dedicated to research and education, recently released a video on their Youtube channel analyzing the claim.

As stated in their video, “The 98% claim (from 2009) was based on a single survey by a University of Illinois professor and a graduate student. They sent a 2-minute online survey to 10,257 earth scientists. They got 3,146 responses to only these two questions…”

The first question asked, “When compared with pre-1800 levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?” The second asked, “Do you think that human activity is a significant contributing factor in changing mean global temperatures?”

Ninety percent of the respondents said that the mean temp had risen, while 82 percent said that human activity was a significant factor. However, the term “significant” was never defined. Furthermore, according to the Heartland Institute, most skeptic scientists would agree with the statistic if the term was defined.



The video explains that when formulating the 97 percent statistic, researchers used only the responses from “climate scientists.” However, only 5 percent of the respondents – 79 people – were climate scientists.

So, out of 10,257 academics that the professor and graduate student identified as worthy survey participants, only 79 were in agreement with their final finding. When calculated, those 79 scientists – now accepted as 97 percent – make up a meager 0.77 percent of academics. And, since only 97 percent of the 79 answered positively (which would be 76.63 people – so we will round to 77), the percentage shrinks from 0.77 percent to 0.75 percent.

Is the Heartland Institute right to call this research project “phony science?”