The estimated economic costs associated with delaying measures to reduce the pace and magnitude of climate change mean policy action is required today, a report from the US Council of Economic Advisers at the White House has concluded.
Although delaying action can reduce costs in the short run, the council argues the net effect of such a hold-up is ultimately costly.
Because CO2 accumulates in the atmosphere, delaying action will increase concentrations.
The longer the delay, the greater the concentration of CO2 will be and the greater the risk. Costs will take the form of either more damage from climate change or financial ones associated with implementing more urgent remedial action.
According to the report, immediate action will substantially reduce the long-term cost of achieving climate targets by sending a signal to the market that will spur development of new low-emission technologies.
An analysis of the cost of delay in terms of hitting a specified climate target suggests net mitigation costs increase, on average, by about 40% for each decade of delay.
The report also concludes that climate change stemming from delayed action creates large estimated economic damages. For example, if delayed action causes the mean global temperature increase to stabilise at 3°C above pre-industrial levels, rather than 2°C, that delay will induce annual additional damages of 0.9% of global output.
The next degree increase would incur greater additional annual costs of 1.2% of global output. And these costs will be incurred year after year.
Potential costs from abrupt, large-scale catastrophic changes in climate reinforce the need to act now, the report states. If an ice sheet melts, for example, it cannot be reconstituted on any societally relevant timescale and could result in massive global costs.