HAWAI'I'S ENVIRONMENT
Observatory charts rise in carbon dioxide
By Jan TenBruggencate
Advertiser Columnist
Each year, in winter, the amount of carbon dioxide in the atmosphere goes up to a new high.
This has been going on since 1958, measured at the National Oceanographic and Atmospheric Administration's Mauna Loa Observatory.
The facility, at 11,200 feet above sea level on the slope of the big mountain, has been continuously tracking atmospheric carbon dioxide longer than any other scientific facility.
Its data are the basis for calculations used by scientists around the world to attempt to predict the future of climate change, because carbon dioxide is a major "greenhouse gas." That means it tends to trap the sun's heat near the surface, as a gardener's greenhouse does.
Different researchers come to different conclusions about the implications of the Mauna Loa carbon dioxide data, but nobody doubts the information itself.
High on a mountain in the middle of the largest ocean, Mauna Loa's atmospheric detection capabilities are superb.
"It's so far from any major land mass that we don't see the influence of any city," said John E. Barnes, station chief at Mauna Loa Observatory. Pollutants from within the Hawaiian Islands tend to blow away before they can affect the sampling site.
When researchers first began studying the level of carbon dioxide in the air, it was about 315 parts per million, measured by volume. They noticed immediately that there seemed to be a seasonal variation.
The carbon levels would rise in winter, and fall to a low in the summer.
Barnes said that in the Northern Hemisphere, it seems that growing plants suck carbon dioxide out of the air during the spring-summer growing season, locking the carbon up in the plant tissues.
In the winter, when plants die and leaves rot, carbon dioxide is released back into the atmosphere.
As the years went by, the researchers also noted that with each passing year, the winter peak was higher.
One conclusion—one that is now widely accepted—is that human activities are causing the rise. The burning of coal and oil as fuel releases carbon dioxide that has long been stored in the Earth. Too, the cutting of forested areas around the world reduces the among of living plant material that can soak the gas up.
Winter levels are now in the area of 370 parts per million, up 17 percent since the counting started 44 years ago.
You can see a graph of the Mauna Loa carbon dioxide data by clicking on the figures box at the CMDL Web site.
More information on the observatory, including a live camera picture of the weather on Mauna Loa, is available at stratus.mlo.hawaii.gov.
Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. You can reach him at (808) 245-3074 or e-mail jant@honoluluadvertiser.com.
