![]() As the warm water cools in the North Atlantic, it sinks to the ocean floor, and then slowly moves southward until it returns once again to the tropics. Warm surface water from the tropics travels northward by the Gulf Stream. What is the Atlantic thermohaline circulation?Ĭlaussen: The Atlantic thermohaline circulation, which includes the Gulf Stream, acts like an oceanic conveyer belt that carries heat from the tropics to the North Atlantic region. That’s why some scientists worry about a catastrophic event - like the breakup of the West Antarctic ice sheet or the collapse of the Atlantic thermohaline circulation. ![]() But there's evidence that some parts of the climate system work more like a switch than a dial: if a certain temperature level is reached, there may be an abrupt and large change in the climate. But even when scientists run scenarios on the world's most powerful supercomputers, they cannot pinpoint how climate will change in specific places or predict whether Los Angeles or other cities will face violent weather.Ĭlaussen:When scientists talk about climate change, they are usually referring to “gradual climate change.” In other words, if the planet warms steadily, the climate changes steadily. In fact, scientists have found this is already happening with rain and snowfall in the United States. In a hotter world, evaporation will happen more quickly, providing the atmosphere with more fuel for storms. Research has shown that climate change might lead to more intense hurricanes and certain other types of storms. Tornadoes strike Los Angeles and grapefruit-sized hail falls on Tokyo.Īctual climate change. In addition, Earth's orbit is in a different phase than during the peak of the last major ice age 20,000 years ago, and the Northern Hemisphere is receiving more solar energy in the summer than would be associated with another ice age. That is because increased levels of greenhouse gases will increase temperatures across much of the planet. Although human-related emissions of carbon dioxide and other greenhouse gases might cool some parts of Earth by affecting ocean currents, they cannot trigger a widespread ice age. A massive snowstorm batters New Delhi as an ice age advances south.Īctual climate change. (Some ocean changes, however, such as the periodic warming of Pacific Ocean waters known as El Niño, may affect regional weather patterns within weeks.) Even if this were to occur, it would take many years or decades because oceans move heat and cold much more slowly than the atmosphere. This could affect currents, such as the Gulf Stream, that transport heat north from the tropics and might result in parts of North America and Europe becoming relatively cooler. ![]() In a warmer world, additional rain at middle and high latitudes, plus melt from glaciers, will add more fresh water to the oceans. Temperatures in parts of the world could drop, but not nearly as rapidly or dramatically as portrayed in the movie. Temperatures in New York City plummet from sweltering to freezing in hours.Īctual climate change. The responses are followed by a list of online resources on climate change. The Pew Center for Climate Change, a nonprofit alliance of major businesses seeking strategies to counter warming, answers some commonly asked questions via its director, Eileen Claussen, who previously has held senior science policy positions at the State Department and National Security Council.
0 Comments
Leave a Reply. |