| The Earth's average temperature IS rising, as the | | | | years. Their 2001 report is projecting that sea levels |
| average temperature has increased by about 1 | | | | could rise anywhere from 4 to 35 inches (10 to 89 |
| degree Fahrenheit (0.6 degrees Celsius) around the | | | | cm) by 2100. |
| world. | | | | This could greatly affect coastal dwellers, as a 1.5 |
| More evidence that the Earth's average temperature | | | | foot (50-centimeter) sea level rise in flat coastal |
| has increased recently can be seen in the spring ice | | | | areas would cause a typical coastline retreat of 150 |
| thaw and fall ice freeze: The spring ice thaw in the | | | | feet (50 meters.) In addition, there are 100 million |
| Northern Hemisphere occurs 9 days earlier than it did | | | | people worldwide that are living within 3 feet (1 |
| 150 years ago, while the fall ice freeze begins 10 | | | | meter) of mean sea level, which means that a rise of |
| days later than it used to. | | | | just 4 inches (10 centimeters) could promote flooding |
| Since weather record-keeping began in the | | | | in many South Sea islands, as well as the U.S. states |
| mid-1800s, the 1990s was the warmest decade | | | | of Florida and Louisiana. |
| recorded. The hottest years include 1998, 2002, | | | | Global warming could have an effect on the ocean's |
| 2003, 2001, and 1997. | | | | circulation system, known as the ocean conveyor |
| The multinational Arctic Climate Impact Assessment | | | | belt. The conveyor belt moderates global |
| (ACIA) report has recently concluded that average | | | | temperatures by moving tropical heat around the |
| temperatures in Alaska, western Canada, and eastern | | | | planet, but an influx of freshwater from melting ice |
| Russia have increased by 4-7 degrees Fahrenheit (3-4 | | | | caps, for example, could cause unforeseen and |
| degrees Celsius) in the last 50 years, which is nearly | | | | possibly fast-paced change to the circulation system. |
| twice the global average. In the U.S.'s northernmost | | | | Climate models suggest that global warming could |
| city, Barrow, Alaska, the average temperature has | | | | cause more frequent and more extreme weather |
| increased by over 4 degrees Fahrenheit (2.5-3 | | | | conditions, including more intense hurricanes and |
| degrees Celsius) in just the last 30 years. | | | | storm surges affecting coastal communities, while |
| The United Nations' Intergovernmental Panel on | | | | heat waves, fires, and drought become more |
| Climate Change (IPCC) is projecting that global | | | | common. |
| temperatures will rise another 3-10 degrees | | | | Increased industrialization and shrinking forests since |
| Fahrenheit (1.6-5.5 degrees Celsius) by the end of the | | | | the 1860s have helped raise the atmosphere's carbon |
| 21st century. | | | | dioxide (CO2) level by almost 100 parts per billion, |
| Rising temperatures have caused Arctic Sea ice to | | | | which has led to an increase in Northern Hemisphere |
| shrink by nearly 30% since 1978, and it has also | | | | temperatures, especially since the 1950s. |
| thinned the remaining ice as well. ACIA predicts that | | | | In the Arctic, for instance, coastal indigenous |
| at least half of the Arctic's summer sea ice will melt | | | | communities report shorter periods of sea ice, which |
| by 2100, and that the Arctic region will increase in | | | | no longer temper ocean storms and their destructive |
| temperature by 7-13 degrees Fahrenheit (4-7 | | | | coastal erosion. Increased snow and ice melt have |
| degrees Celsius) during that same time span. | | | | raised river levels, while thawing permafrost has |
| Greenland's massive ice sheet has enough melt water | | | | caused havoc with roads and other infrastructure. |
| to raise the sea level by about 23 feet (about 7 | | | | This has forced some communities to move away |
| meters.) ACIA projects that that sheet will | | | | from historic coastline locations. |
| experience significant melting throughout the 21st | | | | Studies show that many European plants are now |
| century. | | | | flowering a week earlier and losing their leaves 5 |
| Large amounts of the Earth's fresh water supply is | | | | days later than they did in the 1950s. |
| tied up in the world's many melting glaciers. Montana's | | | | Biologists have determined that many birds and frogs |
| Glacier National Park had 150 glaciers when it was | | | | are breeding earlier in the season. In addition, a study |
| created in 1910; in the early 21st century, it now has | | | | of 35 non-migratory butterfly species shows that |
| less than 30 greatly shrunken glaciers. Tropical glaciers | | | | two-thirds of them are now heading 2-150 miles |
| have been reduced even more, as evidenced by | | | | farther north than they did 20 years ago. |
| Tanzania's Mount Kilimanjaro - its 19,340-foot | | | | There are several signs of global warming in the |
| (5,895-meter) peak has melted by around 80% since | | | | present day. It is likely that there will be more signs |
| 1912 and could be totally gone by 2020. | | | | as time passes if we continue in our current ways, |
| According to the IPCC, the average global sea level | | | | which could lead to major changes for all of us in the |
| has risen 4-8 inches (10-20 cm) over the past 100 | | | | way we live on Earth. |