Conor Whitten: Facts of climate change can’t be denied

Conor Whitten: Facts of climate change can’t be denied
Photo credit: Getty Images.

OPINION: The first step towards recovery is admitting you have a problem. 

One-in-eight New Zealanders still struggle with this.

I'm not talking about binge drinking, gambling or domestic violence - I'm talking instead about climate change. A survey this year of 9000 people found one in eight Kiwis don't believe humans are to blame.

My esteemed colleague Peter Williams, the Magic Talk host, is one of those concerned. He asks why the sceptics are labelled as deniers, and why questions cannot be asked. 

He's right - we should all be allowed to ask questions. But some questions have answers, which should not be ignored.

Peter says today's "climate deniers" are compared to those who denied the holocaust. The difference, he says, is the physical proof.

"The thing is, we know the Holocaust happened. We have physical evidence of graves, of concentration camps, of gas chambers and of people being loaded onto trains to go there and never be seen again."

But we also have real, physical evidence of how greenhouse gases are changing the world. The level of C02 in the atmosphere is measured from the air all around us - you cannot see it, but it's physical proof.

It tells us C02 in the Earth's atmosphere has dramatically increased in the last two centuries, to levels not seen in 3 million years.

Peter asks why we should care about 3 million-year records. After all, the Earth is 4.5 billion years old.

But our societies - and our species - did not exist in those conditions. Modern humans evolved 200,000 years ago. The livestock and crops we rely on for food have been farmed for only the last 12,000. And the cities of Miami, New York and Dunedin - cities put at risk by rising sea levels - are mere hundreds of years in age. Extreme weather, drought, food shortages and rising tides were of little concern 3 million years ago.

The result of all this extra carbon also has real, physical proof. It's called the greenhouse gas effect, and it's been known to science since 1896.

Most of the planet's atmosphere is nitrogen and oxygen, gases which have little effect on heat. But greenhouse gases like carbon dioxide and methane don't allow heat to pass through them - instead, they reflect it back to the Earth. More greenhouse gases means higher temperatures. It is simple cause and effect.

Physical data also tells us the Earth's average temperature has risen nearly 1C since 1880. It tells us we just sweated through the hottest June on record, and 2015-2018 was the warmest four years on record too.

He asks why the Earth has been through warm and cool periods over the last 2000 years. If the Earth can naturally grow warmer and cooler, how do we know this change is our fault?

This question, too, has an answer. Scientists do believe there was a Medieval Warm Period beginning around 1000 years ago. It was followed by what's called the Little Ice Age, which ended about 160 years ago.

But the change the world has seen since 1880 is dramatically faster. Between 950AD and 1850 temperatures changed by fractions of a degree. The change since 1880 is bigger, and instead of taking a millennium, it's occurred in 140 years.

What's changed? An explosion of greenhouse gases, caused by humans, which isn't slowing down.

Those who have questions should always ask them. But they should come prepared to listen to the answers - otherwise "denial" seems a fitting word.

Conor Whitten is Newshub's Australia correspondent, based in Sydney.