The "Keep 1.5 °C Alive!" rallying cry of climate change activists is a fantasy. But a new study in Nature calculates that it may be possible to keep average global temperatures from rising 2 degrees Celsius above preindustrial levels.
Signatories to the 2015 Paris Climate Change Agreement are pledged to "holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels." In order to stay on track toward meeting the 1.5 C goal, the United Nations notes that carbon dioxide emissions must be cut by 45 percent by 2030. Cuts that deep imply global fossil fuel production falling by roughly 6 percent per year and emissions dropping 7.6 percent per year from 2020 to 2030.
Keeping in mind its vested interests, ExxonMobil projects that the global production and consumption of oil, natural gas, and coal in 2030 will be higher than now. An October 2021 United Nations report essentially concurs, warning that big energy producing countries currently "plan to produce around 110 percent more fossil fuels in 2030 than would be consistent with the 1.5°C limit."
It´s clear that the 1.5 C goal is unrealistic. So what about keeping the increase in average temperatures below 2 degrees Celsius above preindustrial levels? A new Nature study says it's possible, supposing that all of the countries that have made pledges to reach net zero emissions of greenhouse gases by 2050 keep their promises. As the U.N. notes, "net zero means cutting greenhouse gas emissions to as close to zero as possible, with any remaining emissions re-absorbed from the atmosphere, by oceans and forests for instance."
"Warming can be kept just below 2 degrees Celsius if all conditional and unconditional pledges are implemented in full and on time," the researchers conclude. "Peak warming could be limited to 1.9–2.0 degrees Celsius." Instead of assuming deep emissions cuts by 2030, researchers in the recent study forecast that global greenhouse gas emissions will peak sometime during this decade. Of course, any expectation that politicians 30 years hence will keep promises made by politicians today is likely to be fantasy, too.
The new study bolsters the conclusions of another study by University of Colorado climate policy scholar Roger Pielke Jr. and his colleagues published earlier this year in the journal Environmental Research Letters. "All of the plausible scenarios," explains Pielke in his Substack newsletter The Honest Broker, "envision less than 3 degrees Celsius total warming by 2100. In fact, the median projection is for 2100 warming of 2.2 degrees Celsius."
Pielke asked then, "Is the world ready for good news on climate?" The new Nature study adds to that good news.