By Bruno Costelini
Oceanographer and PhD candidate in Law at Durham University
Now is the winter of our discontent
Made glorious summer by this sun of York;
And all the clouds that lour’d upon our house
In the deep bosom of the ocean buried.
These first lines of Shakespeare’s Richard III are meant to convey a transition in power in England. Spoken by Richard, the deformed brother of Edward (the sun/son of York, who has just re-ascended to the throne), they disguise his treacherous nature, for only a few lines later he confesses to his intentions of overthrowing the King, killing his other brother, locking up his nephews in the Tower of London, and finally taking over the crown. In the course of the play, Richard manages to carry out his plan, plotting and deceiving those around him. Before it ends, though, fate catches up to him, and he falls from his horse to his death in the Battle of Bosworth.
This week saw the release of the IPCC latest report on the state of our climate. It is only the first part of the Sixth Assessment cycle, delivered by Working Group I, dealing with the Physical Science basis for further reports, to be delivered by 2022. Thus, it synthesizes the latest science and accumulating evidence that explains the increasing temperatures throughout the globe, past, present and future.
The report presents some dreadful conclusions, beginning with the now inescapable (‘unequivocal’) fact of human-influenced warming, at a rate ‘unprecedented in at least the last 2000 years’, greenhouse gases emission being the main driver ‘since around 1750’, reaching a level of 410 ppm for CO2. When it comes to the ocean, the report deems virtually certain that the upper layer (0-700m) has warmed since 1970 due to the carbon dioxide uptake, leading to lower levels of oxygenation, to an increase in the sea level now at a rate of 3.7 mm per year, and to surface ocean pH levels ‘unusual in the last 2 million years’.
Worse, even at the most optimistic scenarios for the coming decades, the report sees a continued increase in temperatures, of at least 1.6 Celsius for 2041-2060, or up to 2.4 °C in the worst case. For 2081-2100, scenarios range from 1.4 °C to 4.4 °C, all according to their best estimates. Hence, even if immediate action is taken and emissions dramatically reduced, the effects of current and past releases will inevitably be felt.
Many changes are already deemed irreversible, ‘for centuries to millennia’, including again, ocean warming leading to upper ocean stratification, ocean acidification, and ocean deoxygenation. Global mean sea level rise in 2100 could range from 0.28-0.55m in the best scenario to 2m in the worst (and up to 5m by 2150), due not only to thermal expansion, but also due to ice sheet melt.
On an optimistic note, the report posits that it is not too late to mitigate some of those impacts, presenting the positive outcomes of reducing and removing CO2 and greenhouse gases in general. These could affect not only air quality but also trends in sea level rise, with effects being felt on a medium to long-term timespan.
Much like the court of London, or the audiences of Shakespeare’s play, for decades we have been prey to the charming discourses of the treacherous fossil fuel economy, sucking up oil and burning it like there is no tomorrow. Embodying their inner Richard III, the industries that profited from those activities masked their intentions and hid known facts about the mounting effects of gas emissions into the atmosphere.
But for a couple of decades now, the game has turned. The villain has shown its face, and we are being forced to acknowledge the hard facts and consequences. We have come to the Battle of Bosworth, and so it is time to abandon our sympathies for the dubious character that insists on clinging to his horse, offering a kingdom for it. Now is the winter of our discontent, and it is up to us to make it a glorious, not a burning summer, and hope those clouds do remain in the deep bosom of the ocean, buried.
Cover Image: An aerial view shows a wildfire in Yakutia, Russia. Available at: https://edition.cnn.com/2021/07/22/world/wildfires-siberia-us-canada-climate-intl/index.html
 William Shakespeare, Richard III, Act I, Scene I
 All quotes from the IPCC ‘Climate Change 2021, The Physical Science Basis, Summary for Policymakers’ Available at https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf
 See, for instance, Naomi Oreskes and Erik M Conway’s ‘Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming’ (Bloomsbury, 2010).