A109 Light Utility Helicopter flight with mayor Gisborne City from the air in November 2023.
Opinion
The World Meteorological Organisation caused a stir last month when it raised its assessment of the likelihood the global average temperature would cross the 1.5C threshold for heating the planet since its pre-industrial state in one year sometime over the next five years to 66 percent; a year ago this
was seen as a 48 percent likelihood. The WMO sees a 98 percent chance one of the next five years will be the hottest on record.
Even when world leaders signed up to the 2015 Paris agreement to keep the temperature rise to 1.5C, or if not then “well below 2C”, it had seemed unlikely that emission reductions would happen fast enough to avoid the 1.5C mark being crossed; and not in one year like being talked about now but for several years, which would constitute breaching the agreement.
Greenhouse gas emission reduction commitments made since 2015 have lowered worst-case scenarios for climate change but the commitments need to be met, and it is clear that drastic action is required to keep the average rise within 2C. In fact, stopping emissions is not going to be enough to keep “well below 2C” — vast amounts of carbon dioxide will likely need to be sucked out of the atmosphere as well.
More radically, the world could be cooled by cutting the amount of sunlight that reaches the Earth’s surface, probably by spraying a steady stream of sulphur into the stratosphere. Another solar geoengineering option is marine cloud brightening, discussed in Gwynne Dyer’s column in the Weekender today — along with the potential funding of such climate interventions by insurers and better-off parts of the world that are highly exposed to rising risks due to climate change, such as hurricane damage.
Solar geoengineering is a form of deliberate climate change with its own potentially dangerous side-effects, so would require extensive research before it could be considered.
