The planet is
warming, from North Pole to South Pole, and everywhere in between. Globally,
the mercury is already up more than 1 degree Fahrenheit (0.8 degree Celsius),
and even more in sensitive polar regions. And the effects of rising
temperatures aren’t waiting for some far-flung future. They’re happening right
now. Signs are appearing all over, and some of them are surprising. The heat is
not only melting glaciers and sea ice, it’s also shifting precipitation
patterns and setting animals on the move.
Some impacts from increasing temperatures are already
happening.
- Ice is melting worldwide, especially at
the Earth’s poles. This includes mountain glaciers, ice sheets covering
West Antarctica and Greenland, and Arctic sea ice.
- Researcher Bill Fraser has tracked the
decline of the Adélie penguins on Antarctica, where their numbers have
fallen from 32,000 breeding pairs to 11,000 in 30 years.
- Sea level rise became faster over the
last century.
- Some butterflies, foxes, and alpine
plants have moved farther north or to higher, cooler areas.
- Precipitation (rain and snowfall) has
increased across the globe, on average.
- Spruce bark beetles have boomed in
Alaska thanks to 20 years of warm summers. The insects have chewed up 4
million acres of spruce trees.
Other effects could happen later this century, if
warming continues.
- Sea levels are expected to rise between
7 and 23 inches (18 and 59 centimeters) by the end of the century, and
continued melting at the poles could add between 4 and 8 inches (10 to 20
centimeters).
- Hurricanes and other storms are likely
to become stronger.
- Species that depend on one another may
become out of sync. For example, plants could bloom earlier than their
pollinating insects become active.
- Floods and droughts will become more
common. Rainfall in Ethiopia, where droughts are already common, could
decline by 10 percent over the next 50 years.
- Less fresh water will be available. If
the Quelccaya ice cap in Peru continues to melt at its current rate, it
will be gone by 2100, leaving thousands of people who rely on it for
drinking water and electricity without a source of either.
- Some diseases will spread, such as
malaria carried by mosquitoes.
- Ecosystems will change—some species
will move farther north or become more successful; others won’t be able to
move and could become extinct. Wildlife research scientist Martyn Obbard
has found that since the mid-1980s, with less ice on which to live and
fish for food, polar bears have gotten considerably skinnier. Polar
bear biologist Ian Stirling has found a similar pattern in Hudson
Bay. He fears that if sea ice disappears, the polar bears will as
well.
