Consider, for example, this clause in Article 2 of the text:
Parties [shall][agree to] to take urgent action and enhance [cooperation][support] so as to (a) Hold the increase in the global average temperature [below 2 °C][below 1.5 °C][well below 2 °C][below 2 °C or 1.5 °C] [below 1.5 °C or 2 °C][as far below 2 °C as possible] above pre-industrial levels by ensuring deep cuts in global greenhouse gas [net] emissions.
The precise target the parties set for an acceptable rise in the global temperature above levels before the Industrial Revolution could have implications for everything from how many hundreds of millions of people suffer from flooding and drought to how many plant and animal species lose significant chunks of their habitats. Many scientists estimate that if greenhouse-gas emissions continue unabated, the average temperature could increase by four degrees Celsius or more by the end of the century—a scenario that might, as Elizabeth Kolbert wrote recently in The New Yorker, “transform the globe into a patchwork of drowned cities, desertifying croplands, and collapsing ecosystems.” If countries instead abide by the pledges to cut carbon emissions after 2020 that they each made voluntarily ahead of the Paris climate summit, the average temperature will likely go up by at least two degrees Celsius, a less-than-catastrophic situation that could “still destroy most coral reefs and glaciers and melt significant parts of the Greenland ice cap, bringing major rises in sea levels,” according to The Guardian.
Ultimately, national commitments to counter climate change will likely not be enough to keep warming from exceeding two degrees, which means Paris negotiators will be seeking some mechanism to build on these commitments and to avoid crossing that threshold (whether, at this point, crossing that threshold can actually be avoided, deal or no deal, is a matter of dispute). The fundamental question at the Paris summit, according to Kolbert, “is who should be allowed to emit the tons [of carbon]” that scientific estimates suggest can still be released this century without pushing average warming above two degrees. “The world has already consumed around two-thirds of this budget,” Kolbert writes.
But as Deconstructing Paris, a New Zealand-based site dedicated to parsing the draft agreement, has observed, the bracket-ridden text also leaves open the possibility that no global-temperature target will even be set, and that no formula will be established for how to divvy up permissible carbon emissions over time. Behold this mind-addling paragraph on national plans to “mitigate” climate change by reducing or preventing emissions:
[Each Party][All Parties] [recognizing the principle of common but differentiated responsibilities and respective capabilities] [shall][should][other] regularly [formulate] [prepare], [communicate] [submit], [maintain] [update] and [shall][should][other] [implement] [fulfill] [intended][nationally determined mitigation [commitments][contributions][actions]] [nationally determined mitigation commitments and/or contributions] [a nationally determined contribution with a mitigation component], [, which can be in the form of co-benefits resulting from [its] [the Party’s] adaptation contributions and economic diversification plans] [programmes containing measures to mitigate climate change] (NDMC/NDMCC)
Take heart: At least all the parties agree that whatever they’ll be doing, they’ll be doing it “regularly.”