With the COP29 global climate conference opening in Baku, Azerbaijan in less than two weeks (Nov. 11), it’s worthwhile looking at some of the recent and sometimes confounding science that will confront the delegates. Whether that science will directly influence the proceedings is doubtful.
It is worth noting that the affair, the 29th meeting of the “United Nations Framework Convention on Climate Change, given the record of the 28 that have come before, will have far less to do with climate science than with international (and often national) politics.
In 2015 at COP21 in Paris, the parties adopted what they called a “legally binding” goal to halt “the increase in the global average temperature to well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels.” Legally binding is, of course, fiction. The targets are only aspirational.
How is the world doing nine years later? According to NASA, the U.S. space agency that monitors global temperature, “May 2024 was the warmest May on the books, marking a full year of record-high monthly temperatures.” For the 12-month period, the average global temperature “was 2.34 degrees Fahrenheit (1.30 degrees Celsius) above the 20th century baseline (1951 to 1980). This is slightly over the 2.69 degree Fahrenheit (1.5 degree Celsius) level with respect to the late 19th century average.”
Does this mean that the 1.5°C goal has been clearly missed? It’s too early to tell. NASA notes that the El Niño and La Niña weather phenomena have an impact on global temperatures in both directions. NASA says that a strong El Niño that began in spring 2023 helped stoke last year’s extreme summer and fall heat.”
NASA reminds us that El Niño’s sister La Niña could cool things down this year. The Associated Press reported Oct. 16, “The National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Center says there is a 60% chance that a weak La Nina event will develop this autumn and could last until March.”
The period of 2020 to 2023 saw a rare La Niña triple dip. The AP quoted NOAA climate scientist Michelle L’Heureux, “We had three back-to-back winters where we had La Nina conditions, which was unusual because the only other case of that happening was back in 1973 to 1976.” La Niña tends to show up more often than El Niño and last longer.
While the world looks like it is nudging up against the aspirational goals of the COPs, are there signs that the various programs that countries around the world have adopted to reduce greenhouse gas emissions are having an impact? The picture is mixed.
The UN’s World Meteorological Organization on Monday (Oct. 28) warned that greenhouse gas concentrations increased in 2023, a record. The WMO said, “Carbon dioxide (CO2) is accumulating in the atmosphere faster than any time experienced during human existence, rising by more than 10% in just two decades.” The WMO said the 2023 increase in CO2, the primary greenhouse “was higher than that of 2022, although lower than that of the three years before that. The annual increase of 2.3 ppm marked the 12th consecutive year with an increase greater than 2 ppm.”
Is the increasing surge of greenhouse gases and atmospheric temperatures producing a detectable surge on the ground? A team of researchers led by Claudine Beaulieu of the University of California at Santa Cruz, in a report published Oct. 14 in the Communications Earth & Environment journal finds, “A current debate centers around whether there has been a recent (post-1970s) surge/acceleration in the warming rate. Here we investigate whether an acceleration in the warming rate is detectable from a statistical perspective…. Our results show limited evidence for a warming surge; in most surface temperature time series, no change in the warming rate beyond the 1970s is detected despite the breaking record temperatures observed in 2023.”
Also, New Scientist reports, This year is on course to be the hottest on record, with an average global surface temperature more than 1.5°C above pre-industrial levels. But there is some better news: the overall amount of heat energy being gained by the planet has fallen sharply from a record spike early in 2023.” The magazine points out that “The balance between heat gained from the sun and lost to space determines how fast the planet warms;”
Also, despite the hyperbolic claims of some activists and scientists that global warming is causing a greater frequency and intensity of extreme weather events, which has been widely adopted by conventional news media, the scientific evidence for these claims is so far missing, as the UN has acknowledged.
“Global emission reduction efforts continue to be insufficient to meet the temperature goal of the Paris Agreement.”
Finally, does society really have the tools and the willpower to reduce greenhouse gas emissions sufficiently to stall global temperature increases? That’s not clear. An Oct. 9 article in Nature by an international team led by Carl-Friedrich Schleussner of the International Institute for Applied Systems Analysis in Laxenburg, Austria, starts with the observation, “Global emission reduction efforts continue to be insufficient to meet the temperature goal of the Paris Agreement.”
That leads to the idea some have advocated for using advanced technologies to reverse course after the goals have been passed, such as sucking CO2 out of the atmosphere. This is given a faux-precision term “overshoot pathways,” — using technology to reverse conditions “that temporarily exceed a targeted global warming limit before drawing temperatures back down to safer levels.” The title of the Nature article is “Overconfidence in climate overshoot.”
The article concludes that “technical, economic and sustainability considerations may limit the realization of carbon dioxide removal deployment at such scales. Therefore, we cannot be confident that temperature decline after overshoot is achievable within the timescales expected today.”
With that background, what’s likely to come out of COP29? If the past is a reliable guide, there will be lots of rhetoric, plenty of disputes, self-aware chest-thumping, and pledges to get together in 2025 and do it all over again.
–Kennedy Maize
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