In Paris, in 2015, an alliance of island nations and climate justice advocates succeeded in making 1.5° C a formal target, as a limit on global warming. With a flashy, interactive graphic opinon piece in The New York Times, Andrew P. Jones, Stuart A. Thompson and Jessica Ma did that victory a disservice.
Success in getting off fossil fuels, and staying below 1.5° C of warming "would significantly reduce the risks and impacts of climate change," according to that Paris Agreement.
The line about the 1.5° C limit is a nod to the fact that already, with over 1.0° C we’re seeing record-breaking wildfires, rainfalls, flooding and hurricane intensities. It is also a recognition that between 1.5° C and 2.0° C, nasty feedback loops are likely to kick in, further destabilizing the climate.
That is, between 1.5° C and 2.0° C of warming, scientists expect numerous so-called climate tipping points to be surpassed. Examples range from melting Arctic oceans and the Greenland ice sheet (leading to runaway sea-level rise) to thawing permafrost (leading to the release of more greenhouse gases into the atmosphere).
The Intergovernmental Panel on Climate Change has provided estimates of the carbon dioxide amounts that can be emitted, corresponding to different probabilities of staying below the otherwise arbitrary 1.5° C and 2.0° C thresholds, respectively.
Jones, Thompson and Ma drew from those estimates to illustrate what it would take to meet the 2.0° C target. With an assist from MIT, they fiddled with emission trajectories to set the year 2060 as an acceptable target on the horizon. That is, roughly 43 years to get off fossil fuels and reach “near zero” greenhouse gas emissions.
This discounts the peril that lies between the 1.5° C and 2.0° C targets. It also stands in stark contrast to the current destruction of communities and the upending of lives due to already existing climate impacts (severity and intensification of hurricanes Harvey and Irma (and Jose?) this year, flooding elsewhere around the world, wildfires, ocean acidification.
As the Times piece notes, some 2100 Gigatonnes of CO2 has already been emitted globally. If we’re to have a decent chance of staying below 1.5 of warming, then the starting point would be 2250 GT, not 2900 Gt.
That means there’s about 150 Gt CO2 remaining in the decent-chance-of-staying-under-1.5° C -degrees-of-warming budget, or about four years at current global emissions rates.
The authors of the Times piece would do well to provide a similar graphic for the 1.5 target, so to not sweep this urgency under the rug.
Climate scientists clearly recommend that we maximize the amount of fossil fuels we keep in the ground.
Children today face coastal flooding, severe storms, and variance from seasonal norms that are all unprecedented in human history, with enormous human and economic costs.
Simply put, it’s now time to move off fossil fuels, rapidly and completely.