This could be a critical error and shortcoming on the part of modelers and planners in projecting costs imposed by inadequate efforts to move away from fossil fuels. Current projections are vital to governments in calculating financial risks and benefits to slashing global greenhouse emissions. The biggest problems with the current projections, as found in this study, is the short-term focus on costs imposed by climate change. There appears to be a nearly unspoken assumption that extreme weather and climate events have short-term, readily calculable costs but these costs are not effectively factored into much longer time spans. In other words, the costs are fixated on the short-term impacts.

As summarized in phys.org, a weekly publication of the American Physics Association: “Extreme events like droughts, fires, heat waves and storms are likely to cause long-term economic harm because of their impact on health, savings and labor productivity.”

Because the economic costs over this century are not being properly modeled to include the long-term economic harm, the international team of scientists wanted to define a more reliable range focused on one widely used climate costs model. They found global GDP due to economic impacts could be 37% lower, compared to the previous study’s figure of 6%. This underestimation, they have found, would be due to the lack of inclusion of the long-term impacts being added to the recognized short-term impacts. Based on the new study’s conclusion, this would mean the climate costs model underestimates the costs by a factor of 6.

The authors recognize there remains considerable uncertainty on exact percentages and, for example, in their range of calculations the upper range number was a 51% drop in GDP. The study did not find much supporting evidence the figure could be much below the 37% number chosen so, in that sense, the authors were conservative. Study co-author Dr. Chris Brierley told phys.org “Climate change makes detrimental events like the recent heat wave in North America and the floods in Europe much more likely. If we stop assuming that economies recover from such events within months, the costs of warming look much higher than usually stated. We still need a better understanding of how climate alters economic growth, but even in the presence of small long-term effects, cutting emissions becomes much more urgent.”

Outside of the scientific and economic issues covered in this study, the authors seem to imply there is something analogous to our short attention span and rapid news cycle that has been ongoing in these previous climate cost models. That is, most of us not in or near Louisiana will not think much of the long-term economic impacts from Hurricane Ida in a few months, even though those impacts will surely extend into years, not just a few months. The same can be said for the terrible wildfires in the West. Even the Pacific Northwest heat wave in late June, now long out of the news cycle, killed several hundred people in British Columbia and dozens in Oregon and Washington. What are the long-term costs of such loss of life? The excess mortality was due to a high pressure heat dome which was truly unprecedented, and strongly tied to climate change.

While it is necessary to undertake costly mitigation and adaptation measures to deal with already ongoing impacts from the warming climate, the study findings confirm it would be less costly to drastically reduce greenhouse emissions rather than to focus more on mitigation. Based on the accelerating pace of warming and its impacts, it would be extremely unlikely the projected costs over this century will be in the older modeled lower GDP range.