How Fast Could Climate Really Change?

So far the climate change models omit the effects of trees and plankton.

by Bruce Torrie

As we enter 2002, let's examine our understanding of the science and politics of climate change. In November 1989, Dr. Gordon McBean, then a UBC geography professor and a lead author of the first report of the Intergovernmental Panel on Climate Change (IPCC), was giving a speech at the Vancouver Court House just prior to the release of the 1st IPCC Scientific Assessment.

I asked Dr. McBean: "What about the Antarctic ozone hole's effect on the rate at which climate change occurs? Won't the ultra violet radiation above Antarctica and its surrounding oceans destroy the plankton? Won't this dramatically accelerate the rate at which carbon dioxide accumulates in the atmosphere, speeding up climate change?"

Dr. McBean replied that the IPCC models on climate change did not account for the role of life – mostly plankton and forests – in assessing the carbon cycle and carbon dioxide (CO2) loading of the atmosphere.

This is a serious omission, because it is the plankton and forests that absorb CO2 and release oxygen. The carbon is incorporated by the trees as wood and the plankton similarly builds tiny shells out of the carbon which at the end of the plankton's life sink to the bottom of the ocean, removing vast amounts of carbon from the atmosphere and storing it in a stable form on the bottom of the ocean.

The oceans around Antarctica are by far the richest of the world's oceans in plankton. Until the early 1990s, scientists thought that plankton was about 1 – 10 times as abundant in polar and sub polar oceans compared to the temperate and equatorial oceans. Plankton likes it cold and is very vulnerable both to warming and enhanced levels of ultra violet radiation. With the discovery of nano and pico planktons – very tiny organisms – scientists changed their calculation to "plankton is 100 – 1,000 times as abundant in the polar and sub polar oceans as compared to the temperate and equatorial oceans."

I believe that this means that most of the world's biomass has perished under the southern polar ozone hole over the last sixteen years since the ozone hole first opened. Each year since 1985 the radiation has affected an ever larger area, destroying more plankton, leading to the increased accumulation of atmospheric CO2. At the same time, we have been deliberately destroying the world's forests – the terrestrial carbon sink – at a rate almost too fast to calculate.

So what will the numbers be if we integrate the plankton and forest destruction in our models of CO2 loading of the atmosphere driving climate change? In about 1997, the IPCC Scientific Committee charged with this responsibility, chaired by Dr. McBean, now ADM in charge of Environment Canada, met in Victoria. Dr. McBean told me: "You will be pleased to hear that our committee is now beginning to consider the effect of plankton and forest die off on the climate change models."

Unfortunately, the committee has not published its conclusions as part of the Third IPCC Scientific Assessment on Climate Change. This means that the role of plankton and forest die off has still not been integrated into the IPCC scientific assessment.

In Great Britain, the Hadley Centre of the UK Meteorological Office has begun to integrate the role of life, mostly the plankton and forests, into its "coupled climate-carbon cycle model" This model is early and as yet does not include the decimation of plankton caused by ultra violet radiation in southern polar and sub-polar oceans. It is still a major step forward in understanding just how dire the situation is and the critical role humanity has played in destroying the forests and the ozone layer.

Richard Betts has published papers integrating the effect of logging and forest die back into the model and has concluded that the atmospheric concentrations of CO2 will build up about 30% faster than suggested by the "lifeless" IPCC model, based on business-as-usual emissions. This means that if we include forest die back the average global temperature increase will be over 8°C (from 1860 – 2100) compared to the IPCC prediction of 5.8°C.

Ninety per cent of the planet's biomass — life — is in the oceans. Most of this is plankton. Ten per cent of the biomass is on land. This is mostly forests. When the plankton die back is added to the models it will demonstrate that climate change will progress much more quickly than even the Hadley Center's coupled climate-carbon cycle model currently predicts.

When CNN interviewed physicist Stephen Hawking on Larry King Live, December 25, 1999 they asked: "So, Professor Hawking, what do you see in the future?" He replied: "If it were only a few degrees, that would be serious, but we could adapt to it. But the danger is that the warming process might be unstable and runaway. We could end up like Venus, covered in clouds and with the surface temperature of 400 degrees."

The main variable that cools the planet is the cloud cover over the oceans that reflects the sun's radiation back to space. Clouds over the oceans also protect the plankton from ultra violet radiation. Some planktons emit sulphur compounds which rise into the atmosphere to become the condensation nuclei around which water vapour condenses to form clouds. If we have less of the plankton, we will have less condensation nuclei and less clouds so it becomes warmer. This negative feed back is only one of many negative feed backs which could drive global warming into Stephen Hawkings "Venus scenario." None of these negative feed backs has been included in the IPCC models, so they are of little utility in predicting the rate at which global warming will really happen.

So what can we do to help protect ourselves and our families? It is clear that we must act, for government has done nothing to avert the problem or warn the population on measures to be taken to adapt to a very inhospitable future of extreme weather events.

* Footnotes:

1 Richard A. Betts: "Offset of the potential carbon sink from boreal forestation by decrease in surface albedo, " Nature, Vol 408 9 November, 2000; "Biophysical impacts of land use on present day climate; near surface temperature change and radiative forcing," Atmospheric Science Letters, Volume1, No. 10.

2 Hawkings quote. See:, Millennium interviews. Stephen Hawking quoted at p. 221, Stormy Weather, Dauncey

[From WS February/March 2002]

5 Issues/yr — $25 print; $15 digital