Radiation poses a serious threat to life on this planet. Earth is naturally bombarded by solar rays and is subject to radioactive radon gas, but life on this planet has evolved more or less alongside the energy from atomic nuclei. But the manmade sources are far more volatile and more likely to cause death on a massive scale because it represents a quick and sudden change from the typical radiation background levels. The largest manmade sources of radiation include X-rays and nuclear medicine, but there is a significant amount of residual nuclear contamination from coal-fired power plants the testing of nuclear weapons.

The effects on the environment of a standard fission or a fusion bomb are severe, but the effects of a dirty bomb could also be significant. See Physical and Environmental Effects: the Effects of Radiological Terrorism. Radical groups continue to seek radioactive material for such a weapon, e.g. FARC Acquired Uranium, Says Columbia. These types of weapons have lingering effects that last for much longer than the typical conventional weapons. Even the most potent ideology doesn’t have a half-life like these.

More information on Background Radiation.

An ice shelf about the size of Connecticut is breaking up and “hanging by a thread” from the Antarctic Peninsula because of global warming, the British Antarctic Survey said Tuesday.  See full article at CNN:
Massive ice shelf on verge of breakup

See a video here: Antarctica’s Wilkins Ice Shelf Eroding at an Unforeseen Pace. It’s also interesting to point out that when an ice-shelf melts, just like ice in a glass, the sea-levl is not affected. It’s the melting of ice that’s on land that will pose problems for sea-levels.