Dr. Tim Patterson
Moscow Times, Oct. 2, 2003
Referenced on the front page of The Moscow Times - http://www.moscowtimes.ru/
Andrei Illarionov, chief economic adviser to President Vladimir Putin, couldn't have been more correct when he said that the science backing the Kyoto accord is far from settled. Trying to understand what is really happening in the field is one of the main objectives of the World Climate Change Conference being held in Moscow this week.
As Dr. Yury Izrael, chair of the organizing committee for the conference, sums it up: "The most important issue is whether ratifying the Kyoto Protocol would improve the climate, stabilize it or make it worse. This is not very clear."
That is an understatement. Izrael is one of thousands of climate experts worldwide who are starting to conclude that the rush to implement drastic greenhouse gas reductions has been premature.
Although many recent developments illustrate this new trend in the scientific community, none is more dramatic than the blockbuster paper highlighted in the July issue of the Geological Society of America's journal, GSA Today. Co-authored by University of Ottawa geology professor Dr. Jan Veizer and Israeli astrophysicist Dr. Nir J. Shaviv, this paper fundamentally challenges the view that carbon dioxide is the principle cause of climate change. Veizer and Shaviv show that the primary driver of the Earth's major climate swings over the past half billion years almost certainly originates with supernovas -- the cataclysmic explosions of the galaxy's largest stars.
Scientists have long observed a consistent trend linking variations in the sun's brightness with the terrestrial climate. Throughout the 20th century, for example, the sun brightened and so, not surprisingly, the Earth warmed. This direct heating may be responsible for about a third of the warming observed. While acknowledging that the sun plays a role, pro-Kyoto scientists still argue that greenhouse gases are responsible for the majority of the warming.
But the models used by the Intergovernmental Panel on Climate Change to support Kyoto do not properly account for changes in cloud cover. This is important since, overall, clouds are likely a cooling influence, so anything that diminishes cloud cover will indirectly warm the Earth. Surprisingly, increases in solar activity tend to reduce cloud cover and so the sun's effects may be far more important than direct heating alone.
Clouds form more readily when tiny particles in our atmosphere known as aerosols pick up electric charges and so more effectively collect water droplets. Recent studies show that galactic cosmic rays, high-energy particles from deep space, act to charge aerosols and thereby create more low-lying clouds. So anything that reduces the galactic cosmic rays hitting the Earth will indirectly warm the planet.
Now, when the sun is more active, it emits more solar wind, which acts to deflect the galactic cosmic rays that would ordinarily hit the Earth. This results in less cloud formation and a diminished cooling effect. The reduction in cloud cover amplifies direct solar heating and so most of the past century's warming may be completely attributable to changes in the activity of our sun. This would imply that carbon dioxide emissions have had, and will continue to have, little effect.
When the IPCC report was assembled, specialists knew that this "natural amplification" of direct solar heating could explain recent warming. However, the IPCC merely labelled the idea "Very Low Scientific Understanding," partly because of insufficient data. It was also difficult to differentiate between the impact of carbon dioxide and solar activity when both were increasing in unison.
Thanks to Veizer and Shaviv, the missing data has now been provided.
By analyzing fossilized seashells, Veizer reconstructed a record of Earth's temperature for the past half billion years and found a repeating cycle of temperature increases and decreases every 135 million years. Although this periodicity corresponds with no known terrestrial phenomena, it does correspond well with our movement in and out of the bright arms of the Milky Way galaxy. Because interstellar matter bunches up in the galaxy's arms, we see the birth of large, very bright, but short-lived, stars that end their lives as supernovas while still inside the arms, giving off powerful bursts of galactic cosmic rays. This causes predictable changes in the amount of cosmic rays impacting our atmosphere, a phenomenon clearly visible in the geologic record.
Veizer and Shaviv found that changes in galactic cosmic ray intensity correlates quite well with the Earth's temperature variations over the past half billion years.
They conclude that 75 percent of the temperature variability of the last half-billion years is explained by cosmic ray changes as we move in and out of the galaxy's spiral arms. Yet, over the same time frame, the geologic record shows essentially no correlation between carbon dioxide levels and temperature.
Veizer and Shaviv use their study results to conclude that a doubling of today's carbon dioxide levels would result in a change in low-latitude sea temperatures of about 0.5 degrees Celsius. This translates into a global temperature rise of only about 0.75 degrees Celsius instead of the 1.5 to 5.5 degrees predicted by the IPCC. This new forecast compares favourably with other predictions as well as recent satellite measurements.
This study, in conjunction with a number of other recent papers, shows that the scientific rationale for Kyoto is now obsolete. President Vladimir Putin's decision to delay Kyoto ratification is clearly the right one.
Dr. Tim Patterson, a professor in the Department of Earth Sciences at Carleton University in Ottawa, Canada, specializes in paleoclimatology. He contributed this comment to The Moscow Times.