Farmers and climate activists alike were presented with a challenging perspective about trees and our industrial climate crisis at a recent Science Wairarapa talk.
The guest speaker was Greg Briner, head advisor to the Parliamentary Commissioner for the Environment, who summarised two recent studies and Commissioner Simon Upton’s views.
The main message from Wellington was that trees are not good for carbon offsets.
Farmers have been earning money through a greenhouse gas offset programme, which involves growing trees to balance out and reduce carbon dioxide pollution produced by factories and farms alike.
The second message was that pine plantations might still be useful in reducing warming effects over the short term, but it would take a lot of land to provide enough trees for a small effect.
Trees are also increasingly at risk.
“Trees are increasingly in danger from wind, fire, pests, and diseases … These are all more common in a warming world,” Briner said.
The bottom line message: trees are not as useful in our fight against industrial greenhouse gas pollution as we thought.
To reduce the heating effect of the methane burped by one cow, a farmer would need to plant 0.6 hectares of pine trees.
“To get the equivalent of a 10 per cent reduction in [national herd] livestock methane emissions, you’re talking about 770,000 hectares of pine plantation forests.
“To put this into perspective, we currently have just under two million hectares of plantation forest. If we double this, we can offset methane instead of CO2 and it would give you an extra 23 per cent or so [in reduction of warming].”
Briner also said a new Climate Change Commission [CCC] study showed the need for a reduction of gross greenhouse gases, not merely net greenhouse gases. In other words, we cannot use trees as an excuse to continue polluting.
Speaking after the event, a beef and sheep farmer attendee acknowledged he felt sensitive over the methane issue and its challenge to his livelihood and career.
Meanwhile, dairy farmer Jim Western said the world is in deep trouble – “We need to use more sustainable electricity and reduce fossil fuel use now” – although he also thought the presentation showed cows in a bad light and accused Briner of “misleading by omission” regarding other causes.
Publisher Julian Bateson, who owns land with pine and native trees, found the talk informative with a lot of detail new to him that was clearly explained. “It was well worth attending,” he said.
Another participant was recent Masters-level geology graduate Robyn Ramsden, who said she didn’t find anything “radically new” in the talk, although it did help her think more deeply about the problem of methane.
“Perhaps we need to be taking reducing methane seriously by actually reducing the causes.”
“We can’t hope to reduce methane or carbon if we are blinded by the trees,” she said.
Information on Science Wairarapa bi-monthly meetings available here: https://waiscience.weebly.com/
