The concentration of carbon dioxide in the atmosphere has reached a record high, according to the latest figures released by an internationally regarded measuring station in the Arctic.
The measurements suggest that the main greenhouse gas is continuing to increase in the atmosphere at an alarming rate.
The level of the gas at the Zeppelin research station in Svalbard, about midway between mainland Norway and the north pole, last week peaked at more than 397 parts per million (ppm), an increase of more than 2.5ppm on 2008. It has since begun to reduce and yesterday stood at 393.7ppm. Before the industrial revolution, the CO2 level was about 280ppm.
CO2 levels recorded in Svalbard tend to be higher than the global average, but scientists said the CO2 level they had measured was unprecedented even for that location.
“These are the highest figures collected in 50 million years,” said Johan Strom, professor of atmospheric physics at the government-funded Norwegian Polar Institute, which collected the data.
“It is not the level of CO2 that is the problem, because the Earth will adapt. What is very worrying is the speed of change. Levels [here] are now increasing 2ppm to 3ppm a year.
“The rate of increase is much faster than only 10 to 20 years ago. You can almost see the changes taking place. Never before have CO2 levels increased so fast,” he said. The global annual mean growth rate for 2007 was 2.14ppm — the fourth year in the last six to see an annual rise greater than 2ppm. From 1970 to 2000, the concentration rose by about 1.5ppm each year, but since 2000 it has risen to an average 2.1ppm.
PATTERN OF INCREASE
“There can be week-to-week or day-to-day variability,” said Thomas Conway, a research chemist at the US National Oceanic and Atmospheric Administration’s (NOAA) Earth Systems research lab in Boulder, Colorado. But he said a 2.5ppm annual increase was “on the high end.”
The concentration of carbon dioxide in the atmosphere is the single number that most potently represents the impact of the burning of fossil fuels on the Earth’s climate. Before the industrial revolution, the level was 280ppm, meaning that for every million molecules in the atmosphere, 280 were CO2. The current global average is 386ppm. The world’s foremost climatologist, James Hansen, argues that we have already exceeded the “safe” level of CO2, and must aim to reduce it to below 350ppm in future to avoid the risk of unavoidable climate change. Others have suggested 450ppm as the limit at which humanity’s gamble with climate becomes too risky. If nothing is done to cut emissions, and the current fast growth continues, CO2 will soar towards 700ppm by the end of the century. Source: The Guardian
“This is part of an overall pattern of CO2 increasing in the atmosphere. Unless the burning of fossil fuels decreases, then the CO2 will not decrease. And if the rate of fossil fuel burning increases, so will the rate of CO2 increases,” he added.
Last week, the NOAA released preliminary figures for its annual greenhouse gas index, which incorporates data from 60 sites around the world — including Zeppelin. Total global CO2 concentration topped 386ppm. In 2008, the global average increased by 2.1ppm, slightly less than the 2.2ppm increase in 2007. NOAA’s primary CO2 measurement station is Mauna Loa Observatory in Hawaii.
CO2 levels are typically higher in the Arctic than the global average because there is more landmass and human activity in the northern hemisphere. As a result, human emissions from factories and transport tend to lead to higher CO2 levels here.
The figures will concern policymakers in advance of global talks on a successor to the Kyoto protocol in December. Climate scientists advise that the world must prevent CO2 levels from rising higher than about 450ppm CO2 equivalent (a measure of global warming potential that incorporates other gases such as methane and is higher than the measured CO2 level) to avoid a 2° C increase on the preindustrial global average temperature.
The Zeppelin research station is on a mountain top approximately 1,100km from the north pole. The closest town, Ny Alesund, is the northernmost human settlement in the world, mainly inhabited by research scientists.