How to have a conversation with a climate change denier.


These days climate change deniers — or climate change sceptics, as some prefer to be called — don’t actually tend to dispute that the climate is changing.

After all the numbers are there: the six warmest years on record since 1880 were 2014-2019; average sea-levels have risen 23 cm since the late 1880s; ice sheets are shrinking by more than one hundred billion tonnes every year; and so on, and so on.

Instead, their ‘denial’ typically centres around the role of humans in contributing to that change. They don’t think we’re to blame, nor that we should panic. All those kids marching in the streets? Brainwashed, they say. The activists warning of the unfolding threat to ecosystems and human lives? Alarmist greenies.

Watch: Jane Goodall on leaving a better world for our children.

Video by ABC

But the thing is, unlike climate change sceptics, those ‘alarmists’ actually have science on their side; decades of credible, peer-reviewed research undertaken by thousands of scientists around the world.

Below, we take a look at some of the key findings so that you can effective conversation with someone who denies the human-driven climate change emergency.

But first, a quick refresher…

Climate change is…
changes in typical weather patterns (and related changes in oceans, land surfaces and ice sheets), occurring over a long period of time.


Climate change is caused by…
excessive greenhouse gases entering the atmosphere. The most important greenhouse gases are water vapour, carbon dioxide and methane. A certain amount occur naturally and act like, well, a greenhouse, in that they trap heat radiation and warm the lower atmosphere, making the planet warm enough for us to inhabit. But since the industrial revolution of the late 1700s, we humans have been adding more and more gasses to that greenhouse, mainly by burning fossil fuels and deforestation. And well, we’re startin’ to really sweat in here.


With that context under your belt, here are five of the most common arguments put forward by climate change sceptics and how you can refute them.

‘Scientists are divided on whether humans have caused climate change.’

Not true. A 2013 analysis of nearly 12,000 studies showed that at least 97 per cent of actively publishing climate scientists agree that climate-warming trends over the past century have been caused by human activity.

In fact, the lead author of that review recently estimated that figure is now likely to have passed 99 per cent.

On top of that, almost 200 leading scientific organisations around the world have issued public statements endorsing this position — think N.A.S.A., the Australian Bureau of Meteorology, the C.S.I.R.O..

So, science is very, very much united.

‘Global warming is part of a natural cycle. It’s been happening throughout history.’

It’s true that the earth has gone through many periods of cooling and warming, driven by greenhouse gas events. And yes, during certain periods millions of years ago, the earth was even warmer than it is today. (Side note: there were mass extinctions then, too).


BUT… research has shown that the warming that’s occurring right now is doing so at a rate that’s:
A) exceptional. That is, at least 10 times faster than any climate shift in the past 65 million years; and
B) cannot be natural.

The ‘not natural’ part is clear given when this change happened.

A study using 700 climate records, showed that the only time in the last 2000 years that the climate around the world has changed at the same time and in the same direction (ie. heating or cooling) has been in the last 150 years. In that time, over 98 per cent of the surface of the planet has warmed.

This has occurred in tandem with an unprecedented recent increase in the amount of greenhouse gases in the atmosphere. In fact, atmospheric carbon dioxide levels, alone, have jumped by 45 per cent since the industrial revolution.

That boost means that carbon dioxide and other greenhouse gases are now at their highest concentrations for more than 800,000 years! (We know this thanks to analysis of air bubbles trapped in ancient Antarctic ice.)

‘Changes in the climate are due to sunspots.’

You may have heard Senator Barnaby Joyce spout this one. But it’s not accurate.

Yes, sunspots (storms on the sun’s surface that come with intense magnetic activity) have the power to modify the climate on Earth.

But as Mark Maslin, Professor of Earth System Science at University College London, pointed out via The Conversation, “scientists using sensors on satellites have been recording the amount of the sun’s energy hitting Earth since 1978 and there has been no upward trend. So they cannot be the cause of the recent global warming.”


‘They can barely predict the weather for next week, let alone years in advance.’

That’s where the difference between climate and weather comes in. Weather refers to the day-to-day fluctuations in the atmosphere, while climate refers to the long-term average of weather patterns.

This is why global warming (a climate event) can exist even though there’s, let’s say, a cold snap (weather event) in Wagga Wagga.

Because climate trends rely on patterns recorded over an extended period of time, they are far easier to predict. This is done using ‘global climate models’: a complex mathematical representation of the major components of Earth’s climate system — atmosphere, land surface, ocean and sea ice — and how they interact.

Listen: The Quicky chats to an expert from the C.S.I.R.O about what Australia’s climate future looks like.

Complicated, sure. But legit.

As Prof. Maslin points out, “There are over 20 major international centres where teams of some of smartest people in the world have built and run [global climate models] containing millions of lines of code representing the very latest understanding of the climate system… Having so many different models constructed and calibrated independently means that we can have confidence when the models agree.”

‘There are more important problems that the Government needs to spend money on right now.’

Of course, there are other problems facing Australia. But some of the most pressing, that is drought and extreme weather events including bushfires, are directly linked to climate change and they’re costing us billions — not to mention human lives and wildlife. By acting now, we could help ease the impact of such events in the future.


Scientists are telling us it is possible to reverse current global warming trends, with shifts to renewable energy and so on (We’ve outlined some of the most viable climate change solutions in a previous article). But the longer we wait the more expensive it will get.

The long-term consequences of inaction are grim for Australia. Our financial regulators acknowledge that climate change is now a central concern for the economy and financial stability; we’re talking farmers producing less, damage to property and infrastructure by extreme weather events and commodity price hikes.

Need something closer to home? If we don’t act on climate change, within a decade, your house will likely be worth less and your insurance will be higher, due to increased extreme weather events and rising sea levels.

Regardless of how you think we found ourselves in this mess, there’s no disputing that there is one. So why not do what we can to clean it up? Even if moving away from reliance on fossil fuels has no impact on climate change (scientists tell us it will, but for the sake of argument…), what’s wrong with having an economy that’s more stable in the long-term, breathing cleaner air and not relying on a sources of energy that are predicted to run out?

Featured image: Getty.

As a media company, Mamamia has never and will never publish any articles or opinions that deny the existence or impact of climate change. Research shows that at least 97 per cent of climate scientists agree: climate change is real and driven by human activity. We vow to choose decades of rigorous, peer-reviewed research over falsehoods that will only stall action on the climate emergency.