In the 2000s, the question of how strong agreement is
among climate scientists that climate change is happening and that
it's human-caused began to gain prominence.
A few papers
answer the question using various different
approaches, ultimately pinning the level of consensus at around
97 or 98 per cent.
Last year, a study by
University of Queensland climate scientist and founder of the
Skeptical Science website, John Cook, revisited consensus on
climate change within the scientific literature.
The researchers examined 12,000 studies. Similar to
other studies, Cook et al.
concluded that 97 per cent of the papers that expressed a
position on the causes of climate change pointed to human activity
as the main driver.
The study received a lot of media coverage at the
11th among new science papers receiving the most attention
online in 2012, and even earning a mention from the US president.
But it's alsoprompted some heated discussion.
Most recently, economics professor Richard Tol
critique of the paper in the journal Energy Policy. Tol
takes no issue with the paper's conclusion about an overwhelming
scientific consensus in the literature. Instead, the crux of his
argument is with specifics of the methodology.
Consensus is complicated. And reducing a complex
question to a simple number is going to be fraught. So why do it?
We asked climate scientists what consensus means to them, if it can
be measured and how they use consensus in their own work.
Why measure consensus?
Climate scientists overwhelmingly agree that recent
warming is being driven by human activity rather than by naturally
occurring processes. That's typically what people mean when they
talk about a 'scientific consensus' on climate change.