Upton told a meeting of the Middle Districts branch of the Farm Forestry Association in Feilding carbon dioxide emitters will pursue forest offsets on a potentially huge scale, which could see millions of hectares of land go into forestry by the second half of the century.
The Bill allows carbon dioxide emissions from the combustion of fossil fuels to be offset by planting trees, an approach that worries him.
“For forests to be a legitimate offset for fossil carbon dioxide emissions there needs to be a broad alignment between the warming caused by emissions and the climate mitigation benefits of the sinks that are meant to be offsetting them. The problem is that there is no such alignment.”
Fossil carbon dioxide emitted into the atmosphere has a warming effect that lasts for centuries to millennia.
“By contrast, most forests store carbon on timescales that last decades to centuries.
“Furthermore, forests are vulnerable to many threats, including fire, pests and diseases, which will be further exacerbated by climate change itself.”
Allowing fossil fuel emitters to use the landscape as a place to store emissions will put farmers in direct competition with fossil fuel emitters for land, he said.
An Upton report, Farms, Forests and Fossil Fuels, advocates a progressive shift to zero carbon dioxide emissions without relying on forest sinks.
“My report made it clear that to safeguard against dangerous climate change we need to reduce carbon dioxide emissions as our top priority.
“The Earth’s average temperature will not stabilise at any level until carbon dioxide emissions reach zero.
“Progress on nitrous oxide and biological methane can help to reduce peak warming but only if fossil carbon dioxide emissions are on a trajectory towards zero.
“By contrast, I concluded that the use of forest sinks as one means of mitigating biological emissions was more justifiable because the durations of the warming effects of biological emissions are better aligned with the duration of the climate mitigation benefits of trees and because it makes practical sense to manage land – whether for forestry or for farming – in an integrated way.
“There is no question that we need to reduce our gross emissions of biological gases.
“But to the extent that we can’t, forest offsetting is a much less risky business than it is with respect to carbon dioxide.”
Upton said allowing only biological emissions to be offset by trees has the advantage of letting farmers balance sources and sinks across the landscape and address other environmental and socio-economic concerns in parallel.
“Land-use change would be driven largely by landowners seeking to rebalance the natural capital on which they depend rather than a largely external grab for sink space by the fossil economy. That re-balancing would ideally be done across property boundaries to get the right trees in the right place and the right animals on the right land, taking into account the multiple environmental problems we’re trying to fix.”
It’s what he calls the landscape approach, which aims to integrate climate mitigation with efforts to address soil erosion, biodiversity loss and water quality.
The Environment Select Committee is considering the Zero Carbon Bill. Submissions close on July 16.
