June 7, 2012 Leave a Comment
“So far, 2012 has been the warmest year the United States has ever seen, with the warmest spring and the second-warmest May since record-keeping began in 1895, the U.S. National Oceanic and Atmospheric Administration reported on Thursday.”
and Really Sweating it…
Another Arctic measurement related to climate reached a milestone this spring, NOAA reported: the concentration of atmospheric carbon dioxide at Barrow, Alaska, reached 400 parts per million, the first time a monthly average for this greenhouse gas passed that level at a remote location.
The level of 450 ppm is regarded by many scientists and environmental activists as the upper limit the planet can afford if global temperature rise is to be kept to within 3.6 degrees F (2 C) this century. Some advocates suggest 350 ppm is a more appropriate target.
The 400 ppm mark for carbon dioxide in less remote locations, such as Cape May, New Jersey, has been reached for several years in the springtime, NOAA said in a statement.
But measurements of carbon dioxide over 400 ppm at remote sites like Barrow – and at six other remote Arctic sites – reflect long-term human emissions of the climate-warming gas, rather than direct emissions from a nearby population center.
The global monthly mean level of atmospheric carbon dioxide was about 394 ppm in April, compared to 336 ppm in 1979, pre-industrial levels of about 278 ppm and ice age levels of about 185 ppm.
The Earth is reaching a “tipping point” in climate change that will lead to increasingly rapid and irreversible destruction of the global environment unless its forces are controlled by concerted international action, an international group of scientists warns.
Unchecked population growth, the disappearance of critical plant and animal species, the over-exploitation of energy resources, and the rapidly warming climate are all combining to bring mounting pressure on the Earth’s environmental health, they say.