If humanity stopped all production of greenhouse gases today, Earth would experience several decades more of additional global warming. That is not simply because the carbon dioxide, methane and other greenhouse gases thrown into the atmosphere by human activity won’t disappear in a day, but because the oceans can’t continue to act as shock absorbers.
Earth has tipped into a heat imbalance since 1970, and this excess heating has thus far been greatly ameliorated because the world’s oceans have absorbed 93 percent of the enhanced heating since the 1970s. This accumulated heat is not permanently stored, but can be released back into the atmosphere, potentially providing significant feedback that would accelerate global warming.
The latest in a series of scientific reports detailing the disastrous course of global warming, “Explaining Ocean Warming: Causes, Effects and Consequences,” concludes that the mean global ocean temperature will increase by as much as 4 degrees Celsius by 2100. In addition to the increasingly unstable weather, more potent tropical cyclones, displacements of aquatic life and boost to atmospheric temperatures that such a rise would cause, massive amounts of frozen methane hydrate in the depth of the seas could be thawed, adding a potent new source of greenhouse gases.
Dozens of climate scientists from around the world contributed peer-reviewed work to the report, research that in turn is based on more than 500 peer-reviews papers. The report builds on the work of the Intergovernmental Panel on Climate Change (IPCC), which in turn was the basis for the Paris climate summit in late 2015. That summit was noteworthy in setting a goal of limiting the increase in temperature to 1.5 degrees above pre-industrial levels, instead of the previous target of a 2-degree rise, often cited as the outer limit before uncontrollable changes are inevitable.
But even if all the national pledges of the Paris climate summit were achieved, global temperatures would rise 2.2 to 3.4 degrees C. by 2100, and the likelihood of all those pledges actually being met are minuscule as there are no enforcement mechanisms. A list of major countries’ pledges reveal a failure to make adequate progress, with many pledges dependent on “cap and trade” scenarios that often amount to subsidies for polluters.
Paris climate summit pledges inadequate
The “Explaining Ocean Warming” report does not sugar-coat that, stating in the conclusion that a fulfillment of the Paris pledges would not result in a return to hospitable conditions. The report says:
“[T]hey actually represent a ‘minimum ambition’ to prevent dangerous anthropogenic interference with the climate system. Achieving the ‘minimum ambition’ will already bring major changes in the functioning and resources of the ocean as we know them. Exacerbating an already concerning situation is the fact that the absorptive role of the ocean is also predicted to decline in the 21st Century, suggesting that the physics and chemistry of the ocean will be significantly different by 2100. As atmospheric CO2 continues to increase as a result of our activities, the solutions (i.e. mitigate, protect, repair, adapt) become fewer and less effective, thus decreasing the long-term ability of humankind to cope with the changes in the ocean that are now being observed.”
The report explains that, volume to volume, sea water is 4,000 more times efficient at retaining heat than is air, providing thus far a buffer to further global warming. But how long can the oceans do this? And at what cost? Coral reefs are dying, sea life patterns are changing, fisheries are in danger of collapsing and oceans are becoming more acidic. Further changes are locked in for decades ahead already, and humanity is ill prepared for this as the stresses on the seas through this excess warming are barely understood. The report says:
“[T]he consequences of increasing human activities have indeed injected vast quantities of heat into the ocean, shielding humanity on land, in so doing, from the worst effects of climate change. This regulating function, however, happens at the cost of profound alterations to the ocean’s physics and chemistry that lead especially to ocean warming and acidification, and consequently sea-level rise. … The problem is that we know ocean warming is driving change in the ocean — this is well documented — but the consequences of these changes decades down the line are far from clear.”
The 13 warmest years for sea surface temperatures have all occurred since 1997, with 2015 the highest yet and eclipsing the previous record of 2014. Parallel to that, August 2016 was the 16th consecutive month that overall global temperatures were the highest on record.
How high and fast will the seas rise?
The continuing building up of heat portends a potentially catastrophic rise in sea level. Two papers published last year calculate that, because of the greenhouse gases already emitted, humanity has already committed itself to a six-meter rise in sea level, and a paper published earlier this year predicts that seas could rise “several meters” in 50 to 150 years.
A still more pessimistic National Oceanic and Atmospheric Administration scientist, Margaret Davidson (giving her personal opinion, a NOAA publicist stresses), says that sea level could rise by as much as three meters by 2050 to 2060, a faster rise than current projections. She cites studies being done on the West Antarctic ice sheet. It is important to remember that the scientific controversy centers on the speed of global warming, not its existence — 97 percent of climate scientists agree that human activity is causing global warming, according to a NOAA study that also found the highest levels of agreement correlate with higher levels of expertise.
A major problem is that global warming, as with the associated environmental problems, can’t be solved within the capitalism that has caused, and is accelerating, the problem. All incentives under capitalism are for more growth and thus more greenhouse-gas emissions, and there is no provision to provide new jobs for the many people who would be displaced should the heavily polluting industries in which they work were to be shut down in the interest of the environment. The private capital that profits from environmental devastation is allowed to externalize the costs onto society, an inequality built into the system. The concept of “green capitalism” is a dangerous chimera.
There is no alternative to a dramatic change in the organization of the global economy and consumption patterns. That means significant reductions in energy consumption, an impossibility within a system that requires constant, unending growth. The rosy predictions of magical technology that will allow business as usual while scrubbing the atmosphere of new greenhouse gases, relied upon in the Intergovernmental Panel on Climate Change report that was in turn the basis for the Paris climate summit pledges, are not realistic, environmentalists say, and thus an illusion. Earth’s environment is crossing multiple points of no return — business as usual is impossible.
If we are to be serious about reversing global warming and repairing the environment, we have to create an economic system based on human need that is stable as a steady-state system and under democratic control, rather than our present authoritarian system that is designed to maximize private profit. That is necessary for economic and political reasons, but the environmental crisis adds another dimension. Otherwise, we “will sleepwalk ourselves into a nightmare, where no level of conservation action in the future will be enough,” in the concluding words of the “Explaining Ocean Warming” report. The task is enormous, but the consequences are even bigger.