The Great North American Megadrought

What is a megadrought?

• A drought that lasts for a few years.

• A more extreme version of a drought that can last for decades.

• A drought that only affects California.

• A drought caused by earthquakes and hurricanes.

What type of data do scientists use to reconstruct historical climates?

• Current weather forecasts.

• Satellite images from the past year.

• Paleoclimate data from ice cores, tree rings, and soil sediments.

• Newspaper articles from ancient times.

What do wide and thin growth rings in trees indicate about past climate conditions?

• Wide rings mean cold temperatures, thin rings mean warm temperatures.

• Wide rings mean more precipitation and favorable temperatures, thin rings mean extreme temperatures and less precipitation.

• Wide rings mean less precipitation, thin rings mean more precipitation.

• Tree rings only show the age of the tree, not climate.

Which of the following are the three main factors that contribute to a drought?

• Volcanic eruptions, ocean currents, and wind speed.

• Soil moisture, atmospheric circulation patterns, and land & sea surface temperatures.

• Forest fires, human activity, and animal migration.

• Sunlight intensity, cloud cover, and air pressure.

How does rain form in Earth's atmosphere?

• Moisture freezes into ice crystals.

• Warm air rises and expands.

• Cold air causes moisture to condense into liquid.

• Water vapor is absorbed by clouds.

What can cause atmospheric circulation patterns to shift, potentially leading to megadroughts?

• Changes in wind speed.

• Cooling or warming of ocean surface temperatures.

• Increased sunlight.

• Volcanic eruptions.

What is predicted to be the main cause of future megadroughts in the North American West?

• A decrease in rainfall.

• An increase in evaporation due to warmer temperatures.

• More frequent wildfires.

• Changes in ocean currents.

Which method involves reusing water from activities like showering and laundry to reduce household water needs?

• Desalination.

• Aquifer replenishment.

• Greywater recycling.

• Cloud seeding.