Facts are then bandied to fit an argument for or against climate change, and on all sides, misconceptions abound. The confusion is not surprising – climate science is a very broad and complicated subject with experts working on different aspects of it worldwide. No single person knows everything about climate change. And for the average punter, it's hard to keep up with all the latest research and what it means. More surprising is the supreme confidence that non-experts (scientists and non-scientists alike) have in their own understanding of the subject. I am a full-time scientist whose area of expertise intersects with certain aspects of climate science. I, too, am not an expert on climate science.

But I do understand how science works. I understand that the current consensus has been reached by thousands of scientists working for decades. And I understand that the vast majority of scientists and scientific bodies, including the Australian Academy of Science, have reached broadly the same conclusions. The academy's "The science of climate change: questions and answers" report – a document written and reviewed by Australia's most expert climate scientists – explains what we know, what we don't know and how we might mediate future changes. These are the real experts on climate change and this is what they're saying: Earth's climate has changed over the past century. The atmosphere and oceans have warmed, sea levels have risen, and glaciers and ice sheets have decreased in size.

The best available evidence indicates that greenhouse gas emissions from human activities are the main cause.

Continuing increases in greenhouse gases will produce further warming and other changes in Earth's physical environment and ecosystems. My own scientific opinions in my areas of expertise are consistent with their conclusions.

Does that mean the academy's view above is endorsed by every expert? No. Like all areas of science, ideas are meant to be contested. The facts and conclusions in this document will be challenged – this is the scientific process that has served humanity so well. But this scientific process has led to a lot of confusion and, in some cases, I dare say, delusion within the broader community. The body of evidence on climate change is not contained in one paper, one set of observations, or by one person – rather it encompasses thousands of people's ideas and observations. This is why it is so important for the country's pre-eminent scientific body to write this document, synthesising all of this disparate information into a coherent assessment of the science. It's much like getting a medical diagnosis from a panel of the country's best doctors. And while some might search around for a different opinion until they get the answer they want to hear, that is not the best way to treat the underlying problem.

Having this information in one place means that the nation's decision-makers have the best scientific opinion on the subject, so that they can stop arguing about the science, and instead focus on their job, which is figuring out the most appropriate policy response to climate change, given the best available knowledge. The evidence is clear: human activities are changing the Earth's climate, and what we do now and into the future will strongly influence the world's weather in the decades and centuries to come. For the future health of our world and our country, Australians, let's quit self-diagnosing on climate change, and act on the expert opinion. Brian Schmidt is a Nobel Laureate and Academy of Science fellow and council member.