冰川融化英文ppt

Advices for individuals
There are many simple things you can do in your daily life — what you eat, what you drive, how you build your home — that can have an effect on your immediate surrounding . we can do many things to make a difference .
Adjust Your Thermostat [‘θɜrməʊstæt ] n.自动调温器, 温度调节装
置
Use Recycled Paper
Take Shorter Showers Install（安装） a Low-Flow Showerhead
Air Dry Your Clothes
Bring Cloth Bags to the Market...
Ecosystems
• The melting polar ice caps have a wide-ranging impact on ecosystems. Migratory（ 迁移的） animal species that depend on the Arctic as a place to feed and reproduce（繁殖） are negatively affected by a loss of sea ice. Species that are native to the Arctic, such as polar bears and seals, are particularly hard hit by sea ice reduction.
Oceans
• The NRDC(美国自然资源保护委员会 )notes on its website that the melting Arctic ice caps could have an impact on the Earth‘s sea levels. As ice sheets （覆盖物）and glaciers（冰川）melt, oceans around the world rise. Rising sea levels could have a devastating（毁灭性的） impact on island nations and cities such as Shanghai that are at or near sea level.
So please take into consideration what we have discussed, and try to do your part. After all, it will be our next generations that will feel and suffer from the effects.
Global Warming
There are many causes of the melting of the polar ice caps and global warming, some of which are natural. However, the activities of man are responsible for much of the rapid change that scientists are seeing. Humankind engages in a multitude of activities that have accelerated the process of global warming.
• I was alarmed by the rapid pace of change there. Worse still, changes in the Arctic are now accelerating global warming. Thawing permafrost is releasing methane, a greenhouse gas 20 times more powerful than carbon dioxide. Melting ice in Greenland threatens to raise sea levels.
polar ice cap polar ice cap melting
causes effects solutions
How do they form?
• At higher latitudes, the earth doesn’t receive much sunlight and, therefore the temperatures remain low for most part of the year, thus the water can’t remain in liquid form and it solidifies(使凝固) water turns into ice.In case of our own planet: the northern and the southern poles are where the ice caps are located.
Extra Effort From Students
Recycle Educate Your Parents No Waste at School Meals Plant Trees Start a Club about Environmental Protection...
If everybody make a little change and contribution to prevent global warming, we would be doing a great thing.
Effects of melting
• Climate • Oceans • Ecosystems
Climate
• Research carried out by scientists at NASA(美国国 家航空航天局) shows that melting ice caps have an effect on the Earth's climate. The polar ice caps that cover the top and bottom of the Earth reflect sunlight into space. When the ice caps recede due to melting, the sunlight is absorbed by the ocean and land instead of being reflected back to space. As a result, the planet becomes warmer, more ice melts and the cycle repeats itself.
• All these factors, when combined, affect the conditions on the planet in the long term and it causes ice ages at different times. During an ice age the ice caps increase in size and they retreat when an ice age ends. These changes occur over a period ranging from thousands to millions of years.
seasonal changes
• They are medium-term changes and they occur every year. Every year with the coming of the winter season, the ice caps begin to expand but they melt again with the coming of the summer seasons.
• The Ice Is Melting
• By BAN KI-MOON
• Published: September 17, 2009 New York Times
• Two weeks ago, I visited the Arctic. I saw the remains of a glacier that just a few years ago was a majestic(宏伟的) mass of ice. It had collapsed. Not slowly melted — collapsed. I traveled nine hours by ship from the world’s northernmost settlement to reach the polar ice rim. In just a few years, the same ship may be able to sail unimpeded（畅通无阻的） all the way to the North Pole. The Arctic could be virtually icefree by 2030.
CAUSESwk.baidu.com
• geological changes
• seasonal changes
• global warming
geological changes
• The causes for these changes can be explained by Milankovitch Cycles. The cycles proposed by him take into account orbital shapes (eccentricity 偏心率), axial tilt轴倾角 (obliquity倾角), axial precession 岁差, apsidal precession and orbital inclination倾角.