In the latest episode of 30 with Guyon Espiner, one of the first voices to sound the alarm on climate change, Dr Michael Oppenheimer, offers both stark warnings and cautious hope as the world grapples with the deepening climate crisis - and reveals his thoughts on climate activists like Extinction Rebellion.
As world leaders gather once again for global climate talks at COP29 in Azerbaijan, there is very little good news to be had.
National heat records across the world have tumbled this year, and there is evidence that the world may have already passed the 1.5 degree threshold agreed to in the 2015 Paris Accord.
Long before climate change dominated news cycles though, Princeton University professor of geosciences and international affairs Michael Oppenheimer was already in the fight.
His career has spanned four decades of groundbreaking work, including direct involvement with the Intergovernmental Panel on Climate Change (IPCC) for which he jointly received the Nobel Peace Prize in 2007, having made significant contributions to understanding the risks posed by a warming world.
He's studied how melting Antarctic ice threatens coastal cities and early on advised figures like Margaret Thatcher on the perils of global warming.
Despite his extensive knowledge of the catastrophic trajectory we are on, he remains, in his own words, an optimist. This optimism, however, is tempered by realism.
"Adapting to our changing climate isn't fatalism," he says. "It's the necessary response to a reality we can no longer ignore."
Michael Oppenheimer has been researching climate change for more than 40 years. Photo: RNZ
The new climate reality
The world has entered what Oppenheimer calls "a brand new climate era".
In his conversation with Espiner, he painted a vivid picture of the changes already underway.
"The climate has already changed. We're here," he says, warning of the extreme weather patterns that have become more frequent and more severe.
"We're seeing storms more intense than ever, sea levels rising to flood coastal areas even at high tide.
"Inland flooding is happening in places that have never experienced it before. And it's not just in the US - this is a global problem."
The effects of these changes are becoming impossible to ignore, Oppenheimer says.
That includes the grim reality of rising temperatures leading to increased heat-related deaths and the devastation of natural ecosystems.
"Almost everywhere on Earth is hotter than it used to be, even New Zealand, and because it's hotter than it used to be, most of those places are seeing more extremely hot days, and extreme heat kills," he says.
"Species are under threat, and certain ecosystems are shrinking, being displaced. We can't pretend this is a problem for the distant future. It's a problem for now."
Firefighters battle a wildfire north of Athens, Greece, in August. Photo: AFP
From greenhouse to hothouse
Originally trained in astrophysics, Oppenheimer pivoted to climate science after stumbling across an MIT alumni magazine article in the late 1960s, detailing the effect human activity was having on earth's natural greenhouse process.
"We've been pumping greenhouse gases into the atmosphere since the Industrial Revolution," he explains.
"It wasn't noticeable [then], but it was going to probably become noticeable over the next few decades."
He isn't happy to have been proved right.
Unlike conventional pollutants, gases like carbon dioxide linger for millennia.
"Even if we stopped all emissions today, the levels of carbon dioxide wouldn't simply wash away," he says. "We'd be dealing with an abnormal climate for centuries."
Yet Oppenheimer is optimistic there is still a path forward. The cost of renewable energy sources like wind and solar are falling, and many countries are already shifting away from coal dependency.
"The new energy sources are now cheaper," he says. "We have a solution to the problem. We just need to implement it faster."
* 30 with Guyon Espiner comes out every week on RNZ, Youtube, TVNZ+ and wherever you get your podcasts.
The Trump factor and fossil fuel obstacles
In the full, uncut interview, recorded just days before Donald Trump reclaimed the US presidency, Michael Oppenheimer is clear-eyed about the challenges ahead.
While Trump has softened his outright denial of climate change, his actions speak volumes, he says.
"His basic philosophy is, let's drill for oil and coal anywhere we can."
Despite this, Oppenheimer says there is still progress being made in the US, with a push towards electrification and a decline in emissions.
Since 2005, US carbon dioxide emissions from energy consumption have fallen by about 20 percent.
"But it's not enough," he says. "The trouble is, we're in a world where some nations are acting, and others aren't."
In addition to that, and despite its downward emissions trend, the US remains the second highest emitter of CO2 after China.
By many measures, humanity has already crossed into what Oppenheimer describes as a "climate danger zone".
This doesn't mean imminent apocalypse, but it does indicate escalating risks. "We're going to see extreme heat, torrential rains, and increased drying of soils, which makes farming and access to drinking water more difficult," he says.
"For a time, wealthier nations like New Zealand and the US may manage, but the strain will build, and poorer nations and communities are already feeling the brunt."
The disparity in resources is a pressing concern for Oppenheimer. In many developing countries, where air conditioning is rare, even a slight increase in temperature can have severe public health consequences, he says.
"We've created a terrible situation. We need to accelerate the transition to new energy sources and protect those who can't afford to protect themselves."
Coastal homes in Tuvalu. The low-lying South Pacific nation has been classified by the UN Development Programme as 'extremely vulnerable' to climate change. Photo: Mario Tama/Getty Images
A call for pragmatic activism
When it comes to climate activism, Oppenheimer supports efforts that educate rather than alienate. He says tactics like vandalising artworks may do more harm than good.
"I don't think it's a good idea and I wouldn't do it myself.
"Non-violent demonstrations and public challenges to politicians or corporations who aren't doing enough - that's the way forward," he says.
Students strike for the climate at Parliament in 2021. Oppenheimer says such non-violent protests and other forms of political pressure are the way forward. Photo: ©VNP / Phil Smith
"We need actions that bring attention and push for change without driving away potential supporters."
Despite the overwhelming evidence of a worsening climate crisis, Oppenheimer's belief in the possibility of change remains unshaken.
"We know what to do. We need to stop using fossil fuels as soon as feasible and scale up renewable energy," he says.
The key, he believes, is in accelerating this transition and ensuring that both mitigation and adaptation strategies are in place. The stakes are undeniably high, but Oppenheimer's message is clear: it's not too late to act.
"We need to plan for a different future and start protecting ourselves today, because the time to act is now, before the risks pile on top of each other."
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