Research and Application News
An unrecognisable Arctic
25 July 2013
In early May 2013, sensors atop a research facility perched on Hawaiian volcano Mauna Loa recorded a sobering statistic. The average daily level of carbon dioxide in the air had reached a concentration above 400 parts per million-a level that hasn't been seen since around 3 to 5 million years ago, well before humans roamed the Earth.
Human burning of fossil fuels continues to increase the amount of carbon, a potent heat-trapping greenhouse gas, in our atmosphere. As a result, our planet is warming, and that warming is pushing Earth systems past critical points. This is especially true within the icy realm of the Arctic, the northernmost polar region of the planet, where the effects of climate change are expected to be most exaggerated and have the biggest impact.
NASA scientists and others around the world are tracking these profound changes and trying to understand what the future may hold. In some cases, Arctic systems may be reaching "tipping points" -critical moments in time where a small change has large, potentially irreversible impacts. Examples of tipping points include the melting of permafrost in the Alaskan tundra and the acidification of the oceans. In other cases, where it may be difficult to quantify a particular tipping point, whole systems are racing toward dramatic transformations, such as the melting of sea ice and the decay of the Greenland ice sheet.