“Current climate change policy suggests a ‘one size fits all’ approach to dealing with emissions,” says Professor Dave Frame, head of Victoria University’s Climate Change Research Institute. “But there are two distinct types of emissions, and to properly address climate change and create fair and accurate climate change policy we must treat these two groups differently.”
The two types of emissions that contribute to climate change can be divided into ‘long-lived’ and ‘short-lived’ pollutants.
“Long-lived pollutants, like carbon dioxide, persist in the atmosphere, building up over centuries. The carbon dioxide created by burning coal in the 18th century is still affecting the climate today,” says Dr Michelle Cain from the Oxford Martin School at the University of Oxford. “Short-lived pollutants, like methane, disappear within a few years. Their effect on the climate is important, but very different from that of carbon dioxide, yet current policies treat them all as equivalent.”
The research collaboration proposes a new approach to climate change policy that would address the effects of these different emissions. This would be particularly relevant to one of New Zealand’s biggest industries: agriculture.
“We don’t actually need to give up eating meat or dairy to stabilise global temperatures,” says Professor Myles Allen from the University of Oxford, who led the study. “We just need to stop increasing emissions from these sources. But we do need to give up dumping carbon dioxide into the atmosphere. Climate policies could be designed to reflect this.”
“Under current policies, industries that produce methane are managed as though that methane has a permanently worsening effect on the climate,” says Professor Frame. “But this is not the case. Implementing a policy that better reflects the actual impact of different pollutants on global temperatures would give agriculture a fair and reasonable way to manage their emissions and reduce their impact on the environment.
“Implementing a policy like this would show New Zealand to be leaders and innovators in climate change policy. It would also help New Zealand efficiently manage their emissions, and could even get us to the point where we manage them so well we stop contributing to global climate change at all.”
This work is funded by the Oxford Martin Programme on Climate Pollutants: https://www.oxfordmartin.ox.ac.uk/research/programmes/pollutants. A briefing note based on this work, “Climate metrics under ambitious mitigation”, can be found at: https://www.oxfordmartin.ox.ac.uk/publications/view/2601.