The world is striving to reach net-zero emissions as we try to ward off dangerous global warming. But will getting to net-zero actually avert climate instability, as many assume?
Our new study examined that question. Alarmingly, we found reaching net-zero in the next few decades will not bring an immediate end to the global heating problem. Earth’s climate will change for many centuries to come.
We found Earth’s climate would continue to evolve under all simulations, even if net-zero emissions was maintained for 1,000 years. But importantly, the later net-zero is reached, the larger the climate changes Earth would experience.
Even just a five-year delay would affect on the projected climate 1,000 years later. Delaying net-zero by five years results in a higher global average surface temperature, a much warmer ocean and reduced sea ice extent for many centuries.
Australia is close to the Southern Ocean, which is projected to continue warming for many centuries even under net-zero emissions. This warming to Australia’s south means even under a net-zero emissions pathway, we expect the continent to continue to warm more than almost all other land areas on Earth.
For example, the models predict Melbourne would experience 1°C of warming over centuries if net-zero was reached in 2060.
Net-zero would also lead to changes in rainfall in Australia. Winter rainfall across the continent would increase—a trend in contrast to drying currently underway in parts of Australia, particularly in the southwest and southeast.
One thing is very clear: there is a pressing need to push for net-zero emissions as fast as possible.