Dynamic nowcast of the New Zealand greenhouse gas inventory
This provides timely emissions estimates for policymakers in New Zealand, though it is incremental as it applies existing methods to a new domain.
The authors tackled the problem of outdated greenhouse gas emissions reporting in New Zealand by developing a machine learning approach to nowcast national emissions with only a two-month latency, estimating a 0.2% decrease in gross emissions since 2020 as of July 2022.
As efforts to mitigate the effects of climate change grow, reliable and thorough reporting of greenhouse gas emissions are essential for measuring progress towards international and domestic emissions reductions targets. New Zealand's national emissions inventories are currently reported between 15 to 27 months out-of-date. We present a machine learning approach to nowcast (dynamically estimate) national greenhouse gas emissions in New Zealand in advance of the national emissions inventory's release, with just a two month latency due to current data availability. Key findings include an estimated 0.2% decrease in national gross emissions since 2020 (as at July 2022). Our study highlights the predictive power of a dynamic view of emissions intensive activities. This methodology is a proof of concept that a machine learning approach can make sub-annual estimates of national greenhouse gas emissions by sector with a relatively low error that could be of value for policy makers.