2011-04-26 16:22:06Treehugger transcript #5: Understanding Climate Denial: Impossible Expectations
John Cook

With 97% of climate scientists and scientific academies all over the world convinced, we now have an overwhelming consensus that humans are causing global warming. Nevertheless, climate deniers still claim "the science isn't settled". They cite areas of uncertainty like the behaviour of clouds, arguing we should delay climate action until we understand every aspect of climate.

There will always be areas of our climate where we can improve understanding. Science is never 100% settled - it deals in probabilities, not certainties. Nevertheless, there are areas we understand with high confidence.

We're confident that humans are raising carbon dioxide levels in the atmosphere. This is confirmed by isotope measurements of the air, corals, oceans and tree rings. We're confident that this extra carbon dioxide is trapping heat. This is accurately calculated, double checked by satellites finding less heat escaping to space and triple checked by surface measurements finding more heat returning to Earth. We're confident that global warming is happening, with indications of warming being found all over the planet.

Because there are aspects of climate science still being investigated, climate deniers say "we don't know everything therefore we know nothing". This is denying all the evidence that tells us we know enough to act.

To say we shouldn't act on climate change until we achieve 100% certainty is to say we should never act. We put seat belts on our children with just the slightest chance of an accident. Why do we risk the world we'll hand over to our children when scientists say there is more than 90% chance that we are causing global warming?

2011-04-26 16:52:50
Alex C


Sorry John, I must have been away when this Treehugger transcript series started in this forum - what exactly are all of these for?  Are these going to be publications in Treehugger as part of a series of articles?

2011-04-26 17:27:39Audio recordings
John Cook

I'm going to record these as audio recordings, in my nasally Aussie twang, then Treehugger will add visuals to make them short web videos. More details at Transcript #1:


2011-04-26 19:13:20
Alex C


Ok, thanks John.

2011-04-27 07:45:30
Peter Miesler

I like the seat belt quote!

2011-04-27 13:32:57Seatbelts
James Wight


Seatbelts may not be the best analogy because they're mandatory.

2011-04-27 14:34:35analogy
Dana Nuccitelli

i like it as an analogy for protecting kids, who get to inherit the problem.  Even if it weren't mandatory, parents would buckle their kids in.