While much of the global climate debate has focused on rising temperatures over the past four decades, some researchers and commentators argue that a return to glacial conditions could represent an even greater long-term threat to human civilisation.
They note that Earth remains technically within the Quaternary Ice Age, a period that began about 2.58 million years ago and is characterised by the presence of permanent ice sheets at the poles. Despite concerns about “global warming”, around 10 per cent of the world’s land area remains covered by glacial ice, with Antarctica alone containing roughly 90 per cent of the planet’s ice volume.
Australian climate researcher and journalist Peter Clack points out that modern civilisation developed during the relatively warm and stable Holocene interglacial period, which began about 11,700 years ago following the end of the last major glaciation. Previous warm periods, including the Eemian interglacial around 130,000 years ago, are believed to have experienced temperatures higher than those recorded today.
Any return to ice age conditions could trigger a crisis unmatched in all human history.
Earth is still technically in an ice age and average global temperatures of around 15°C degrees are still much lower than the long-term global average of 16°C to 18°C A global warming scare… pic.twitter.com/7hCAG6DpMD
— Peter Clack (@PeterDClack) June 5, 2026
Clack argues that Earth’s climate has historically been shaped by long-term natural cycles, including changes in the planet’s orbit known as Milankovitch cycles, as well as tectonic shifts that influenced ocean circulation and polar ice formation.
The Antarctic ice sheet remains the dominant ice mass on Earth, covering around 14 million square kilometres and reaching depths of nearly five kilometres in some locations. During the Last Glacial Maximum between 26,000 and 19,000 years ago, global ice coverage was approximately three times greater than it is today.
Clack says that if another glacial period were to begin sooner than expected, the consequences for agriculture, infrastructure and global population centres could be severe. He notes that modern cities, transport networks and food production systems were established during an unusually warm climatic interval and may be poorly adapted to advancing ice sheets or major cooling.
However, mainstream climate science continues to project that “human-driven greenhouse gas emissions” are causing global temperatures to rise and are likely to delay the onset of any future glaciation for many thousands of years.
The reality is pollution and environmental degradation are the real problems. Climate change a nice distraction and money making Ponzi scheme for the venture capitalists, who are also in large part the worst polluters/environmental vandals. I see too they now want to mine NZ conservation land.
Humans will adapt we’ll have no choice
Great, now we can get rid of NZs climate change obligations and RCP 8.5 worst case scenario modelling based on temp rises. There’s no excuse for more warming taxes when the evidence says the opposite.
Oh. And stop the sun-shielding and rain forming exercises. We see you pilots out there drawing chemical lines in our skies. You’re fiddling with systems you cant even guess at, let alone forecast. NIWA -here’s looking at you.