Loss of Arctic ice isn't just a threat to polar bears. Climate scientist James Hanson has just published a science brief on the NASA website about why those ice sheets are so important (besides providing an habitat for polar bears) and why we need to keep funding research that uses satellites to monitor the state of the world's ice sheets.
It is easy to see why this feedback amplifies the climate change, because reduction of ice sheet size due to warming exposes a darker surface, which absorbs more sunlight, thus causing more warming. However, it is difficult for us to say how long it will take ice sheets to respond to human-made climate forcing because there are no documented past changes of atmospheric CO2 nearly as rapid as the current human-made change.
One big uncertainty is how fast ice sheets can respond to warming. Our best assessment will probably be from precise measurements of changes of the mass of the Greenland and Antarctic ice sheets, which can be monitored via measurements of Earth's gravitational field by satellites.
Figure 2 shows that both Greenland and Antarctic ice sheets are now losing mass at significant rates, as much as a few hundred cubic kilometers per year. We suggest that mass loss from disintegrating ice sheets probably can be approximated better by exponential mass loss than by linear mass loss. If either ice sheet were to lose mass at a rate with doubling time of 10 years or less, multi-meter sea level rise would occur this century.
The available record (Fig. 2) is too brief to provide an indication of the shape of future ice mass loss, but the data will become extremely useful as the record lengthens. Continuation of these satellite measurements should have high priority.
Via Michael Noble
Caltech theoretical physicist Sean Carroll, author of Something Deeply Hidden: Quantum Worlds and the Emergence of Spacetime, explains the concept of a “dimensions” at five different levels of complexity. Dr. Carroll sure has a big brane.
In 1936, the Tasmanian tiger (Thylacinus cynocephalus) was declared to be extinct. Yet in the last three years, there have been eight reported sightings according to Tasmania’s Department of Primary Industries, Parks, Water and Environment. I hope it’s true. From CNN: While stories abound that some continue to live in the remote wilds of Tasmania, […]
Who doesn’t love a free meal? From Nautilus Live: During the final dive of this year’s Nautilus expedition season, our team discovered a whale fall while exploring Davidson Seamount off central California’s coast with researchers from Monterey Bay National Marine Sanctuary. The skeletal remains of the whale lying on its back are estimated to be […]
We can’t all go through life with just a pair of sneakers and flip-flops. Sometimes, you have to invest in a pair of high-quality dress shoes. However, you’ve probably discovered that high-end footwear almost always comes with eye-popping price tags. You’ve got to compromise on second-hand or just suck it up and take out a […]
We have a theory about those throw blankets that are barely big enough to cover your legs. The only people who seem to make them or use them are grandmothers, and the blankets are only that small because Nana got bored halfway through the sewing job. Look, we’re sure she means well. But if you […]
Remember when the default state of your online presence was anonymity? That’s not so clear-cut anymore, and the worst part is you may not even know who is using your data or what they’re using it for. Small wonder that so many people are choosing to surf through virtual private networks. VPNs filter web access […]