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The heat's in the sun
LAWRENCE SOLOMON, Financial Post
Published: Friday, March 09, 2007
We live in extraordinarily hot times, says Sami Solanki of the Max Planck Institute for Solar System Research in Germany. In 2004, he led a team of scientists that, for the first time, quantitatively reconstructed the sun's activity since the last Ice Age, some 11,400 years ago. Earth hasn't been this hot in 8,000 years and, he predicts, the hot spell will carry on for a few more decades before the sun turns down the heat.
The 19th and 20th centuries are especially noteworthy. "The sun is in a changed state. It is brighter than it was a few hundred years ago and this brightening started relatively recently -- in the last 100 to 150 years," he says. "The sun has been at its strongest over the past 60 years and may now be affecting global temperatures."
Dr. Solanki gives cold comfort to those who claim that global warming took off with the Industrial Revolution, and that the warming we've seen over the last century is mostly man-made. To demonstrate how unlikely this is, Dr. Solanki shows an almost perfect correlation between solar cycles and air temperatures over the land masses in the Northern hemisphere, going back to the mid 19th century.
For example, when the length of solar cycle increased dramatically, as it did in from 1910 to 1940, so did the temperature on Earth; when it decreased, as it did from the 1940s to the 1960s, so too did Earth temperatures. Dr. Solanki's startling correlation marked a pivotal point in the climate change debate: Its publication, more than any other single event, caused researchers around the world to examine the role that the sun plays in heating and cooling our planet.
Not that Dr. Solanki discredits the role of man-made greenhouse gases, such as carbon dioxide. These have probably played a large role in Earth's climate, he believes, but only since 1980 or so, when the sun's almost perfect correlation with Earth temperatures ended. He also believes that evidence that greenhouse gases have played a larger role in climate change may some day turn up, because his near-perfect correlation does not constitute proof. To date, however, he hasn't seen anything compelling that undermines his own findings.
The answer to most of the global warming we have seen over the past century, Dr. Solanki believes, will likely be somehow associated with the sun, and involve one or more of its parameters. It could be the sun's total irradiance, he states, citing work by others that he respects, or it could be the solar spectral irradiance, in particular with regard to ultraviolet radiation in the stratosphere. Or it could be the sun's open magnetic flux, which modulates the galactic cosmic-ray flux. Or it could be other factors -- many potential solar drivers of our climate exist.
Dr. Solanki is especially taken with the work of the Danish National Space Agency, which demonstrated the dramatic effect that cosmic rays can have on cloud formation, and thus temperatures -- "the mechanism is just too beautiful to ignore," he offers.
Among the factors that he believes hold great promise, and that cry out for investigation, are the sun's irradiance and its magnetic field, which underlie all solar activity. "Unfortunately, regular and detailed measurements of the sun's surface magnetic field are only available for a few decades, not long enough for comparison with climate," he says on his Web site. "Records of the solar irradiance are available for an even shorter length of time" -- accurate measurements began in 1978 using instrumentation aboard spacecraft. With knowledge of these fundamental determinants of Earth's climate still in their infancy, we cannot act with confidence on climate change.
Dr. Solanki's recommendation: more research, and lots of it. To uncover a possible connection between solar irradiance and magnetic-field variations and climate, he thinks it necessary to extend the irradiance record to earlier times with the help of models. To understand the mechanisms responsible for variations in solar brightness, it is necessary to study solar variability on time scales of days to centuries.
Until the research is in, he believes, the story of what drives climate change remains unknown.
LawrenceSolomon@nextcity.com
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Bob Brinsmead
The amount of CO2 or carbon inhaled is just as important as the amount exhaled. It is not fair to focus alone on the amount of CO2 or GHG that the US produces without taking into account how much the country absorbs. According to Huber (Hard Green) the US manages to balance out the carbon budget by absorbing as much as it exhales - in forests, agriculture and landfill (garbage disposal) etc. Garbage is mostly carbon. Secure landfills is a means of sequesting away millions of tons of carbon instead of returning it to the atmosphere. This is another argument against a lot of effort (and GHG) put into recycling. At the end of the day some recycling is not cost effective, and if it is not cost/energy effective it is not helping to balance things out.
Of course the really big gap in understanding the carbon cycle is the micro organisms in the soil and in the sea, amounting to more than two thirds of the world's biomass. How much CO2 does this two-third plus absorb and emit? We now know that cows and sheep emit more GHG by farting than the entire human transport system. About 12 months ago the Max Planck Institute learned something new - that living trees and other green stuff produce from 10 to 30% of all emited methane. Prior to this discovery, it was thought that methane was produced only in the absence of oxygen. But this is all dwarfed by what two-thirds of the world's biomass is doing all the time. Some of the micro organisms are plants and some are animals, and some are not exactly one or the other. Yet they have a vital impact on the carbon cycle. Do they emit or absorb more when things warm up a bit, and how much? There is currently a big argument on how much trees and agricultural crops grow faster when the air is enriched with CO2 and how much this helps to keep everything in balance. But the bigger question is how do the tiny plants/animals under the sod and in the sea react to CO2 enrichment and/or change in temperature.
People used to worry that the earth would run out of oxygen if more trees were cut down in the Amazon. But if a meteor hit the earth and killed every animal and plant on the face of the earth, it would not wipe out all the micro-organisms. They make the oxygen. So after the passage of time this ferment of life would replenish the earth, complete with a diversity of plants and animals. The earth is a lot more resiliant than generally believed.
The carbon cycle is just like the water cycle. What goes up must eventually come down. What is emitted in water vapour must eventually be returned to the earth in precipitation. All the carbon emited in CO2 must also be returned to the earth in the photosynthesis and other carbon absorbing processes - although this is not as rapid a recylcing process as it is in the case of water - but the principle is the same.
Apparently it is established that in the recent warming process over the last 100 years, most of the warming is (1) at night (2) in the winter months and (3) in the Northern Hem. It is not really global warming in the sense that there has been almost no increase in temperature at all in the Southern Hem. Whilst there is melting in the Artic and over-all loss of ice, the opposite is true of the Antartic as a whole - infact, temperatures there have dropped. None of this was foreseen by the Computer Modelling.
It seems also that GHG, necessary for the earth to be livable, acts to cushion to equalize temperature variations around the world. More GHG may not be so bad in that it may moderates climate variations north to south, night to day, winter to summer. Anyhow, the greatest GHG by far (95%) is water vapour. Increased solar activity causes more evaporation and hence more GHG which forms clouds and causes more precipitation, and the consequent moderating effect. The CO2 GHG effect appears to be much less than the sun/water vapour effect.
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Wendell Krossa
Yes, because for every good and service we consume there is an energy cost. And this footprint idea comes from Bill Rees at UBC. The ecological footprint was originally his design. What Bill Rees did not take into account fully was such things as the technological improvements in agriculture that enable us to grow more on less land. This is a lessening of the human footprint and it has led to large amounts of farmland being returned to forest in the US, Europe and probably elsewhere. Also, energy use has improved in places like the US due to increased efficiency in the way we use energy. This too lessens the human footprint. Again, human ingenuity is not factored fully into Rees’s calculations. His solutions also do not grasp the efficiencies attained through international trade. He wants people to become more local in their buying patterns. That would not lessen but would increase the human footprint.
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Bob Brinsmead
Very well said. And think of the energy efficiency and GHG saved by electronic/computer chip technology replacing all those farting horses delivering messages.
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Wendell Krossa
To add to these comments- it is not even Northern Hemispheric warming entirely. Apparently, Alaska is an exception with a temperature experience that is flat over the century. And then there is upper and lower atmosphere warming. Which is really happening?
And now we are just starting to get the research from cosmic rays and solar ray interactions. Cosmic rays energize the nuclei that cause water droplets to form, hence cloud cover and cooling. Solar radiation cycles blow this away and hence less cloud forms, hence warming. So many elements in this complex, nonlinear system. Some are positive feedback, some negative. It almost appears guided (ooops) or at least with some amazing capabilities to balance and even things out in order for life to continue and to develop on this Earth. Let me not dare introduce purposiveness into the discussion.
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