The better Attenborough doco on climate change

Friday, 3 May 2019

Methane bubbling up through Arctic lakes like this could deliver the climate system another blow.

OPINION: If you watched David Attenborough's Netflix documentary series Our Planet, you were probably as horrified as I was at those now infamous scenes of walruses tumbling off cliffs to their deaths in Russia.

Attenborough has another documentary out, Climate Change: The Facts, which gives a less emotive and ultimately more enlightening picture of the future we face in a warming world.

The BBC doco hasn't screened here, but I found it easily on YouTube. It comes complete with its own troubling scene. In the Arctic Circle, Alaskan ecologist Dr Katey Walter Anthony is pictured stabbing her pen knife through the ice covering a frozen lake.

There's a hiss of gas. That's escaping methane, which is 20 to 30 times as potent as carbon dioxide as a greenhouse gas.

A walrus in trouble in a recent David Attenborough documentary upset many viewers.

* A bizarre bubbling lake symbolises the danger to Earth as the Arctic heats up

* Farm animals responsible for quarter of global warming, study shows

* Human role in climate change is clear**

Carbon gets most of the attention in the climate change debate because globally we emit more of it and it sticks around in the atmosphere longer than methane. But methane belched out by our sheep and cattle accounted for 42 per cent of New Zealand's total greenhouse gas emissions in 2017.

Scientists here have been employed for years with the task of trying to lower those emissions. Their colleagues overseas are attempting the same for rice paddies, where bacteria in the water and the rice plants themselves produce the gas.

That painstaking work, if successful, could amount to very little if we start to see methane bubbling up through the melting ice in Arctic lakes and escaping into the atmosphere in large quantities.

'If you look out across the millions of lakes in the Arctic, you start to wonder just how much methane all of those lakes could release,' says Walter Anthony, after igniting a bubble of methane.

The Arctic's permafrost, the land permanently locked up in ice, is melting also, which threatens to release even more methane, carbon dioxide and nitrous oxide, the other big heat-trapping gas.

A study last month estimated that the economic cost of warming in the Arctic will amount to about US$67 trillion even if we meet our current inadequate pledges under the Paris Agreement. If we can contain global warming to 1.5C, the cost drops to US$25 trillion and we may be able to avoid the ice melt that could trigger the feedback loop resulting in more warming.

It's a huge ask, but Attenborough, in the twilight of his life, isn't giving into despair.

'There is still time if we act now with determination and urgency.'