350ppm: NASA's Maximum Carbon Dioxide Level for the Earth - Where Do We Stand?
A few years ago, scientists in the Arctic made a startling discovery. They noticed that the Arctic ice was melting. This alone wasn't surprising. The scientists expected the Arctic ice to be melting, as they were well aware of rising global temperatures. However, it was the speed at which the ice was melting that was so surprising.
The Arctic ice was melting at a rate that far exceeded even the most pessimistic climate models at the time. It was clear that the models of climate change at the time were already obsolete. Some kind of threshold had been passed and climate change was progressing at a rate far faster than expected. This was evident not only in the melting Arctic ice, but it was echoed in many other aspects of the world climate. For instance, at the same time the ice was melting, methane levels in the atmosphere were skyrocketing (as the result of the Arctic tundra thawing).
Around this time, scientists at NASA released information they had been compiling and announced a figure that has been described as "the most important number in the world." According to NASA's figures, the maximum amount of carbon dioxide (the primary greenhouse gas) that can be supported safely by the earth's atmosphere is 350ppm (parts per million). As long as the amount of carbon dioxide doesn't exceed 350ppm, the earth will be able to sustain life as it has for thousands of years.
So, how close are we to reaching the maximum of 350ppm? We've already left it in our dust. Currently, carbon dioxide levels in the atmosphere sit at 390ppm. The rapidly melting ice was a sign that the global climate is changing far faster than anyone expected. The implications of this are frightening. We no longer need to change our ways with the goal of preventing catastrophic climate change from happening in the future. We're well past that point. Global warming is a reality and we now need to find ways to not only prevent it from getting worse, but also to fix the extensive damage that has already been done to the planet.
Unfortunately, our politicians are lagging behind when it comes to making any real change a reality. At the G8 summit earlier this year, the leaders of the G8 nations (including Barack Obama) worked on a deal that would limit the concentration of carbon dioxide in the atmosphere to 450ppm. That won't be good enough.
We're already above NASA's limit of 350ppm, but that doesn't mean we are all doomed. Think of it this way -- it isn't healthy to eat to much that you weigh 400 pounds, but it's not necessarily a death sentence. It's possible to start to eat healthy foods, start exercising and get your weight back under control. That's what we need to do with our planet. Unfortunately, our leaders only seem interested in half-heartedly starting a fad diet.