How do scientists reach consensus

consensus /kənˈsɛnsəs/
noun
1. a general agreement.
"there is a growing consensus that the current regime has failed."

Did you know that 97% of published peer-reviewed climate papers with a position on human-caused global warming agree global warming is real and we are the cause. (See http://theconsensusproject.com)

But how do all these scientists get to agree, considering that the field of climate change science is made up of different disciplines, like atmospheric science, the study of ice, ecosystems, water, energy, agriculture, political and social science researchers?

Many think consensus is reached by the worlds top scientists all voting on an issue at hand with the majority votes then becoming the consensus.

But arriving at a consensus in science is different. 

There is no vote.

The first key to how the process works is to understand the term “peer-reviewed.” When a paper has been peer-reviewed, it means that it has been evaluated by a number of qualified scientists and found to have followed legitimate scientific methods. This is obviously a critical step.

Scientists can then argue about the findings of the peer-reviewed paper. The arguments stop when the sheer volume of consistent evidence becomes too compelling to ignore. 

Scientists change their minds on the basis of the evidence at hand, and a consensus emerges over time. 

Once they stop arguing and debating, ie a general agreement is reached about the conclusions, they start relying on each other's work. When one scientist builds on the work of another, he or she acknowledges the work of others before them through something known as citations.

Here’s what is important about citations. The work that forms the foundation of climate change science is today cited with great frequency by many other scientists, showing that the theory is widely accepted by the scientific community - and relied upon.

All this is important background to have because there is a lot of misinformation on the topic of climate change and the consensus that exists among experts from different fields. In the US for example, only 16% of adults know that the expert consensus on this topic across disciplines is 97%!

The truth is the worlds top scientific experts from the various disciplines agree we are on a human-caused global warming trajectory with dire consequences to all life on earth including our own. 

(See this study: Consensus on consensus: a synthesis of consensus estimates on human-caused global warming)