Читать книгу Climate Change For Dummies - Elizabeth May - Страница 72

To look forward, scientists make climate models (a model in this case is a computer program) to simulate the functioning of the Earth’s atmosphere and climate. These models cover the atmosphere, oceans, land, and ice of the planet. Researchers input data about the climate and how it works, and then start modifying that data to create various alternative scenarios.

Source: National Oceanic and Atmospheric (NOAA). Vostok Ice Core data and Mauna Loa carbon dioxide observations. Graph: John Streicker.

FIGURE 3-3: GHG levels and temperature fluctuations over the past 420,000 years.

These models have been proven; they work. Even conservative financial newspapers not known for positive views on climate change admit that the models have been “largely correct” in indicating the future path. The models keep getting more comprehensive and detailed — now people can see with real clarity the effects of continuing to emit carbon into the atmosphere.

The modelers are able to look at what would happen if, say, temperatures went up by, say, 3.6 or even 10.8 degrees F (2 or 6 degrees C) above 1850 levels. (These temperature increases refer to the global average, which we discuss in the following section.) (See the “How climate models work” sidebar, in this chapter, for more information.)

In particular, the models show how sensitive the climate is to what may seem like very small changes in temperature.