An item in this week's news shows that their ongoing research has produced some startling results. It is not the first time that those instruments have done so.
Sitting at the top of a tall mountain, swept with persistent winds, the Mauna Loa observatory provides a wonderful place to sample "average" air -- untainted by local pollution, and well-mixed with gasses from around the planet.
Back when the gas samples were first gathered there in the late 1950s, that wonderful mid-ocean setting allowed scientists to discern the "breathing" of the Earth's Northern Hemisphere. In the spring, when plants kick into active photosynthesis, the biosphere breathes in, and atmospheric carbon dioxide levels drop slightly. In the fall and winter, when plants are dormant, the hemisphere exhales, and CO2 levels rise. The cycle repeats every year. That global phenomenon had never been measured before.
After a few years of careful record keeping, the scientists were surprised to find that those annual cycles were not perfectly symmetrical. Each year, the autumn rise would go a little bit higher, and the spring dip wouldn't be quite as deep. In the gradual climb of those seasonal variations, the first clear record of steadily rising levels of atmospheric carbon dioxide was seen. That finding is the basis for current research on climate change.
When you consider the enormous volume of air that is involved, it is truly astounding that humanity has had such a dramatic effect. By burning fossil fuels (coal, oil and gas), and by disrupting parts of the carbon cycle (cutting down forests, for example), we have changed the composition of the entire atmosphere.
For 40-some years, the instruments in Hawaii have watched the CO2 levels inch up. In 1958, carbon dioxide was measured at 314 parts per million. Each year, the figure went up by about one part per million, and the rate slowly accelerated. In the last decade, the CO2 levels were rising by 1.8 ppm per year.
This winter, data from Mauna Loa provided yet another surprise. After years of fairly consistently rising CO2 levels, this year's records show a startling jump. In one year, the reading went from 376 to 379 ppm -- a single year increase of 3 parts per million.
There is no easy explanation for the rapid change. One prominent scientist worried publicly about "feedback effects." As rising levels of carbon dioxide cause global warming, the higher temperatures trigger other effects that release yet more greenhouse gasses into the atmosphere. For example, thawing of the Arctic tundra allows large amounts of methane to escape from the soil.
Other researchers looked to the rapidly expanding economies in China and India, and their growing use of fossil fuels. As two of the world's most populous countries, their impacts on the global atmosphere and climate are very significant.
In 1958, the average global level of carbon dioxide was 314 parts per million. Now it is 379. The Intergovernmental Panel on Climate Change projects that, if unchecked, atmospheric carbon dioxide concentrations by 2100 will be somewhere between 650 to 970 parts per million. As a result, the panel estimates, average global temperature would probably rise by 2.7 to 10.4 degrees Fahrenheit between 1990 and 2100.
As I noted a month ago, there are important uncertainties in the effects of such changes. Climate shifts in one part of the world can trigger changes -- like distortions in ocean currents -- that might bring about widespread regional cooling trends.
What cannot be questioned, though, is that a doubling or tripling of carbon dioxide in just 150 years will have profound effect on our global climate.
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At the same time that rising concentrations of greenhouse gasses touched the headlines, a more pervasive news story had to do with rising prices at the gas pump.
Retail prices for gasoline are hitting record levels across the US. Prices in some areas have gone above $2 gallon. The reports are misleading, though. Many experts have pointed out that, adjusted for inflation, gas is cheaper now than it was 30 years ago.
Even so, the record prices have created widespread grumbling and political turmoil. President Bush has accused Senator Kerry of blocking legislation that would have increased oil drilling, including the proposals to tap the Arctic National Wildlife Refuge. Kerry has called upon Bush to keep gas prices down by releasing fuel from the National Petroleum Reserve.
To the best of my knowledge, neither candidate has commented on the news from Mauna Loa. Neither one has had the courage to say that cutting back on our use of gasoline would be a great thing for the planet. Both seem to be committed to keeping gas cheap and plentiful -- although through different strategies.
Those sort of political policies explain why Mauna Loa has recorded more CO2 in the atmosphere every year. Our political "leaders" are incapable of challenging the dependence on oil that is threatening the stability of our planet's climate.
If such truth cannot be voiced on the campaign trail, can it be spoken from the pulpit? Or is the church in this day also afraid of offending a fickle constituency?
I pray that the church will have the wisdom and courage to speak the truth about this dire threat to the health of our planet.
(Copyright 2004 by Peter Sawtell - Reproduction is permitted provided that you include acknowledgement of the author and a link to Eco-Justice Ministries (www.eco-justice.org).)
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Letter to the Author: Peter Sawtell at ministry@eco-justice.org