4. The role of the ocean in climate change
The IPCC and its supporters also betray a remarkable ignorance about the role of the worldwide ocean in climate change. First, they argue that the extra contribution to global CO2 by human emissions is dangerous because the ocean has reached saturation point with carbon dioxide. They believe that this extra contribution from human emissions is causing sea levels to rise.
a) Are human emissions of CO2 causing sea level to rise?
One of the main scare tactics employed by the IPCC and its supporters is to claim that human emissions of CO2 are causing sea level to rise in a way that will threaten much of the world. There is in fact no evidence that sea level is rising in the way that climate models predict.
Statements made by the IPCC and its followers talk about “sea-level change” as if this were a simple matter. It is not. For a start, it is necessary to distinguish between eustatic changes, which relate to a notional world-wide average; and local relative sea-level (LRSL), which corresponds to changes in actual sea-levels at real and particular coastal locations.
Figure 1 displays eustatic changes in sea-level based on evidence from many sites since the end of the last ice-age. It shows a dramatic rise in sea-level, of about 130 m between about 20,000 years and 7,000 years before the present (BP), with a much milder rise since, of much less than a metre in the last 1,000 years. It should be noted, however, that such data do not permit the prediction of future shore-line positions at any one location, which would need to take into account local uplift or subsidence of the land substrate and also local sediment supply.
Post-glacial sea-level rise (Global Warming Art (2011))
As Robert Carter has stated: …the geological substrates differ from place to place and are rarely absolutely stable; rather the substrate is sinking in some places (for example, on delta coasts, such as around the Gulf of Mexico or in Blangladesh) and rising in others (for example, in many, but again not all, places in earthquake-prone countries like Japan or New Zealand). As a result, we see around the world a complex pastiche of different rates of local sea-level rise or fall, with the position of the shoreline at any one time or place being dependent on the interaction of three things – the rate of substrate movement up or down, the rate of sediment supply from rivers versus marine transport or erosion, and the rate of change in eustatic sea-level. (see Carter, 2010,Climate: the counter-consensus,p. 92)
All the evidence in fact shows that contrary to the IPCC’s claims, sea-level rise is not accelerating. UK oceanographer Simon Holgate (2008) analysed nine long sea-level records for the period 1904-2003. He found that between 1904 and 1953, sea-level rise was 2.03 mm per year, compared with 1.45 mm per year for the period 1953-2003.
Further proof that sea-level rises are not increasing, as the climate models predict, comes from a paper by Phillip Watson (2011). Based on century-long tide gauge records from Fremantle, Western Australia (1897 to present); Auckland Harbour in New Zealand (1903 to present); Fort Denison in Sydney Harbour (1914-present); and Pilot Station at Newcastle (1925 to present), Watson concluded there was a consistent trend of weak deceleration from 1940 to 2000. Climate change researcher Howard Brady of Macquarie University was quoted in The Australian of Friday 22 July 2011, p. 1, as saying that the recent research meant sea level rises accepted by CSIRO were already dead in the water as having no sound basis in probability. He added that divergence between sea-level trends from climate models and sea-level change from the tide-gauge records was now so great that it was clear there is a serious problem with the model.
b) Can human emissions of CO2 warm the oceans?
This view that human emissions are the cause of rises in sea level can in part be rejected in terms of the Earth’s actual annual Carbon Budget, which is discussed at greater length in the document 6 Is CO2 a threat? As is pointed out there, the total emissions from the earth range from 192 to 224 gigatonnes of carbon per year (Gt C/ year), while human emissions in 2011 amounted to 10 Gt C/ year. Note that the human emissions are considerably less than the natural variability in the total emissions. So how can the 0.05% of emissions due to human emissions be upsetting the balance?
Secondly, the IPCC has claimed on numerous occasions that human emissions of CO2 are heating the ocean. Robert M. Carter, 2010, Climate: the counter consensus, ch.4 has pointed out that the ocean has a heat capacity 3,300 times more than the atmosphere. I believe that even this figure is an underestimate. It is easy to see why this is so. At standard temperature and pressure (0°C and 100 kPa) dry air has a density of 1.2754 Kg/m3. The density of water at 0°C is 999.8395 kg/m3. In other words, water has 783.94 times the density of air. In addition, we must consider the total mass of both the atmosphere and the oceans. The oceans of the world have a far greater mass than the atmosphere: 1.5 x 1018 tonnes compared with 5 x 1015 tonnes. In consequence, the mass of the ocean is about 300 times that of the atmosphere. It follows from this that the ocean has a far greater heat capacity than the atmosphere, specifically 783.94 x 300 = ~235,000 times more. The oceans of the world have an average depth of 5 km. If all the available heat in the atmosphere were applied to the ocean, it would warm only the upper 0.21 meters of the worldwide ocean to the same temperature as the atmosphere. Thus it is impossible for the atmosphere to exert a significant heating effect on the ocean, as the IPCC and its supporters have claimed.
Far from the atmosphere warming the ocean, it is the ocean that controls the warmth of the lower atmosphere in three main ways: through direct contact; by infrared radiation from the ocean’s surface; and by removal of latent heat by evaporation. We have had a demonstration of the power of oceans to influence the atmosphere in that fact that in late 2010, a strong El Niño event raised world temperature by ~0.55°C, according to the University of Alabama’s satellite-based measurement of temperatures. The strong La Niña event, in early 2011, which followed, caused a rapid fall of ~0.65° to a decline of -0.10°C below average. Incidentally, the 2010 El Niño rise was preceded by a fall in temperature averages of -0.30°C during 2009.
A further point made by Professor Carter is that while the time constant of the atmosphere, during which a molecule of CO2 may be circulated worldwide, is about one year, that of the ocean is one thousand years or longer. Thus it is quite likely that the outgassing of CO2 evident in the twentieth century may have been caused by the Medieval Warm Period, of about 1,000 years ago.