The German economist Ottmar Edenhofer, who co-chaired the IPCC committee that wrote the most recent UN report, commented in the New York Times: “We cannot afford to lose another decade.” If we do it becomes extremely costly to achieve climate stabilization.
The way we have been buying time to date and may be able to forestall the day of climate reckoning even longer was suggested by James Lovelock in a recent Nature interview when he pointed out, ‘The thing we’ve all forgotten is the heat storage of the ocean — it’s a thousand times greater than the atmosphere and the surface. You can’t change that very rapidly.”
A study lead by Yair Rosenthal of Rutgers University notes that for the past 60 years heat has been accumulating in the oceans, which has acted like a buffer against global warming. Now however the oceans are absorbing heat 15 times faster than they ever have over the previous 10,000 years and although this may give scientists and policymakers more time to deal with the issue of climate change, Rosenthal says the problem is real and must be addressed.
“We may have underestimated the efficiency of the oceans as a storehouse for heat and energy,” he said. “It may buy us some time – how much time, I don’t really know – to come to terms with climate change. But it’s not going to stop climate change.”
A clue as to what has been happening since the turn of this century, when atmospheric warming appeared to level off, was revealed by the study lead by Professor Matthew England of the University of New South Wales (see video). It found that stronger than average trade winds, typically associated with La Nina events, was moving heat deeper into the western Pacific.
As can be seen from the following diagram, La Nina winds pile up warm surface water in the west where they mix the heat to deeper water.
When these winds subside the level of the western Pacific also subsides and the heat, as evidenced by the thermocline,comes closer to the surface in the west while the warm layer thickens in the east.
These El Niño events are typically associated with some of the warmest years on record as evidenced by the following NOAA graph of Global Annual Temperature Anomalies from 1950–2012.
It is anticipated this year is shaping up to be another El Niño year and as England notes the heat absorption of the oceans that brought about the hiatus may also reverse causing the ocean to lose the heat they have absorbed back to the atmosphere. In his words, “we expect quite rapid warming to occur”.
As can be seen from the following representation of the ocean thermocline there is about 20 times more ocean than the 230 meters that takes up heat in La Nina years.
By moving more heat below the thermocline, it can be diluted, with less likelihood of its rapid return.
By moving it to 1000 meters, the thermal expansion of the oceans, which causes about a third of currently measured sea level rise would also be reduced.
Massive deployment of this or similar type systems can buy us time as well as address the real problem of climate change. Such systems, which on a full cycle basis are one of the lowest producers of CO2/kwh of electricity, can provide us with as much energy as we currently derive from fossil fuels.