Among many doom-and-gloom forecasts about the sustainability of the planet; and the risk of an ‘existential crisis’ due to rising temperatures, one scientist has made a simple statement:
It’s not as bad as it once looked
David Wallace Wells is a journalist and editor for New York magazine. He is not what many would call a ‘climate change denier’ – he’s written books such as The Uninhabitable Earth. Despite his possible bent towards alarmism, he has recently published an article noting that the worst case scenarios that have been postulated are unlikely to occur. The article notes:
The RCP8.5 scenario is one of four included by the IPCC in their last major assessment report, in 2014, to model possible paths forward — the worst one, tracing the highest arc of emissions and warming outcomes this century. It has shaped a lot of scientific research conducted in the interim; a very common approach is for a particular paper to highlight projected climate impacts in a low-end emissions scenario (either 1.5 degrees or 2 degrees Celsius) and a high-end one (somewhere in the neighborhood of 4 degrees), then describe the low-end outcome as the climate future “if we achieve the goals of the Paris accords” and the high-end one as “business as usual.” …
…the Breakthrough Institute … modeled the remainder of the century based on some very conservative assumptions. In one scenario, they assumed emissions would peak in 2040 and hold steady rather than decline until 2100; in the other, they assumed emissions would steadily grow from 2040 until the end of the century. They ran those emissions figures through the IPCC’s own basic temperature calculator and found “that transitions in the global energy system over the past decade mean that a conservative business-as-usual projection of current trends in the energy system continuing is now likely to lead to warming of around 3C by 2100.” Further, while they acknowledge a higher-emissions world than the IEA projects is possible, they conclude that “it may be possible under an optimistic business-as-usual case to have as little as 2.5C warming by the end of the century, though anything below that is very unlikely to happen in the absence of policy given the rate of emissions reductions required.”
http://nymag.com/intelligencer/2019/12/climate-change-worst-case-scenario-now-looks-unrealistic.html