Climate action at COP28 held up by debate about the words

The UN Conference of the Parties meetings, as evidenced this year at COP28, have grown large and unwieldy, and with so many lobbyists it’s difficult to make progress on addressing the central issues of human-induced climate change. Much of the discussion involves negotiation of the exact wording.

From a scientist’s point of view, it’s not so complicated – the evidence has grown stronger and stronger, as warming and related weather extremes pile up. This year will become not only the hottest year on record but it will beat all previous years by an unprecedented amount. Helped by a strong El Niño that developed after April, the global temperature for the year looks like being about 1.2C above the 20th Century mean and 1.4C above pre-industrial conditions.

The warming is caused primarily by increased greenhouse gases in the atmosphere, particularly carbon dioxide emitted through human activities. Atmospheric carbon dioxide concentrations at Mauna Loa Atmospheric Baseline Observatory in Hawaii, for instance, are 50 percent higher than pre-industrial values. The causes of the increases are primarily the burning of fossil fuels, despite what the COP28 host Sultan Al Jaber might have us believe.

At the core of this year’s summit sits the Global Stocktake, a report card on where the world stands eight years after signing the Paris Agreement, and how countries plan to fix their inevitable shortcomings. After gathering all the relevant information, beginning two years ago, the data has been evaluated, and now the response has to be formulated and agreed to. 

At COP28, the EU, the US and climate-vulnerable countries have been trying to ensure new plans don’t exempt any industries and cover all greenhouse gases, not just carbon dioxide. China has apparently agreed to this but other countries, including Saudi Arabia and Russia, are pushing for the continued use of fossil fuels. India has been pitching itself as the voice of the global south.

Yet the sub-continent is massively dependent on coal and is the world’s third biggest carbon producer. With its population of 1.4 billion, India argues its per-capita emissions last year were less than a sixth of the US’s (population: 332 million). But the atmosphere and climate system care not one iota about per capita emissions – population matters enormously.

New Zealand has been added to the official list of more than 100 countries supporting a pledge to triple renewable energy and double energy efficiency by 2030. Climate change minister Simon Watts said the pledge’s targets were global in nature, leaving flexibility for individual countries to tailor their approaches. New Zealand already has a substantially higher share of renewable electricity than most other signatories, but we will need to expand supply of electricity to electrify cars, buses, trains and industrial processes that burn fossil fuels.

The second most important greenhouse gas is methane, and the story there is more ambiguous.  Methane is a potent greenhouse gas but has a short lifetime and turns into carbon dioxide and water vapor over about 12 years. The complications stem from the large biogenic sources of methane, from wetlands, agriculture, including rice paddies, and livestock while there are also substantial contributions from fossil fuel sources and the resulting fugitive emissions from leaky mines, pipelines, fracking, and so forth. 

Recent satellite sensing technology has enabled many leaks and sources of fugitive methane to be identified, and on December 4, the US Environmental Protection Agency announced its final rule on methane pollution, which the agency says will reduce emissions from the US oil and gas industry by about 80 percent.

The rule dictates how the oil and gas industry find and fix leaks, it strengthens provisions about flaring, and increases emissions standards for pumps. On the same day at COP28, it was announced that some 50 oil and gas companies worldwide have pledged to shore up leaky methane systems by 2030, and other oil and gas companies have vowed to fight such rules. 

The main focus at COP28 has been cutting fossil methane, which is doable and also necessary, because methane ends up as carbon dioxide. In contrast, biogenic methane is circular; it comes from carbon dioxide in the atmosphere that is taken up by grass during photosynthesis, eaten by cattle (for instance), and the fermentation in the animal’s stomach results in methane being expelled by the animal.

But in defence of cows, they, like trees, also take up carbon, to form beef, leather and dairy products. They help remove carbon dioxide from the atmosphere temporarily. The climate has already adjusted to methane levels from New Zealand cows and beef, and, provided there is no increase in stock, the biogenic methane produced won’t contribute to further climate change. 

However, there are major quandaries with methane because global concentrations continue to increase at alarming rates. It has been possible to identify the main sources as primarily from wetlands in the tropics. How much of this trend may be a consequence of climate change is quite uncertain as natural variability plays a strong role. Continuing tropical deforestation and conversion of land to ranches with cattle will undoubtedly exacerbate methane production. 

Regardless of these uncertainties, the pledges by many fossil fuel companies and countries to try to eliminate fugitive emissions of methane is most welcome.  Whether a phase-out or even a phase-down or “reduction” of fossil fuels will be endorsed will be interesting to see. Our world depends on what they finally agree on, including the words they use.