The Cape Grim Baseline Air Pollution Station situated on the northwest tip of Tasmania acts as one of the world’s key sentinels of atmospheric composition change. During ‘baseline’ periods, air reaching the station has travelled across the Southern Ocean for many thousands of kilometres and is thus as free from local anthropogenic and terrestrial signals as anywhere on the planet. Therefore, the baseline record at Cape Grim tells the ongoing story of underlying and accelerating global atmospheric composition change in the modern era.

In 2015 the landmark Paris Climate Agreement aimed to catalyse action to rapidly reduce greenhouse gas emissions in order to limit global warming to well below 2ᵒC above pre-industrial levels and avoid tipping points in the climate system that might unleash runaway positive feedbacks on radiative forcing. If we are not too late to avoid tipping points in the natural system, successful global action reducing anthropogenic emissions should be evident in a slowing of the growth rate of the major greenhouse gases at Cape Grim.

In this presentation, we will review the growth rates of carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) at Cape Grim in recent years to see if there’s any evidence for progress towards the aspirations of the Paris Agreement.