ISU - Science

Front

What causes the weather?

Back

• Interactions between water and air on Earth and energy from the Sun contribute to our weather. Energy from the Sun heats Earth’s atmosphere, creating winds and other air movement. Water in oceans, lakes, and rivers evaporates, cools, and condenses. This process forms clouds that can produce rain or snow. Ocean water moves in currents from the poles to the equator and back again. Together, air movement and water movement create weather.

Front

What is the climate? How is the climate determined?

Back

Climate: The usual pattern of weather in a region over a long period of time. 

To determine the climate of a region, climatologists collect weather measurements made over 30 years or more and average the results.

Front

What is the difference between weather and climate?

Back

• Weather describes the atmospheric conditions over a short period of time—an hour, a day, or even a week. 

Climate describes the typical weather you can expect in a region based on weather data gathered over many years.

Front

What is a meteorologists? When they describe the temperature what are they describing?

Back

Meteorologists gather information on weather around the world and use this information to forecast the weather for specific areas. They are describing temperature, type and amount of, precipitation, wind speed, relative humidity

• atmospheric pressure, presence of fog, mist, or cloud cover

Front

What are the problems with rising temperatures, rising sea levels, and melting glaciers, ice sheets, sea ice?

Back

rising temperatures: In Canada, average national temperatures have increased by 1 °C in the last 55 years 

Rising sea levels: Even small increases in sea level can create devastating floods in low-lying countries

Melting glaciers, ice sheets, sea ice: can cause serious water shortages, Artic sea is disappearing

Front

What is thermal expansion and what affect does it have on sea level rise?

Back

Thermal Expansion is when water expands slightly when warmed up. Scientists believe that thermal expansion has been responsible for a lot of the rise in sea level over the past 120 years. 

• Thermal expansion is very small, but since the oceans are so deep, it is enough to make a difference.

Front

What changes are happening in ecosystems because of climate change?

Back

Trees, shrubs, and other plants across North America are flowering earlier in the spring. Animals such as squirrels are breeding earlier in the year. Animals and plants are slowly migrating toward the poles and to higher altitudes as their regions warm up.

Front

What proves that the climate is changing?

Back

Rising temperatures, melting glaciers, ice sheets, sea ice, rising sea levels, thermal expansion, changes in severe weather, changes in precipitation patterns, changing seasons, and changes in ecosystems.

Front

What are feedback loops? What is a positive feedback loop? What is a negative feedback loop?

Back

• Feedback loop are when the cause creates an effect that impacts the original cause. 

• In a positive feedback loop, the effect increases the original cause. 

• In a negative feedback loop, the effect decreases the original cause. 

• Feedback loops can also make it difficult for climatologists to predict the effects of changes.

Front

How does water vapor feedback loop work? Is it a positive or negative feedback loop?

Back

It is a positive feedback loop. Water vapor enters the atmosphere as the climate warms up through evaporation. Since water vapor is a greenhouse gas, it traps infrared radiation emitted by Earth. More water vapor also leads to more clouds. Low clouds trap thermal energy near the surface while high clouds reflect sunlight back to space.