The Hydrologic and Carbon Cycles: Always Recycle! - Crash Course Ecology #8

What are the two main biogeochemical cycles discussed in the lecture?

The carbon cycle and the hydrologic (water) cycle.

What drives the hydrologic cycle?

The energy supplied by the Sun and the wind.

What is precipitation?

The process when water condenses in the atmosphere and falls as rain, snow, sleet, or hail.

What is evaporation?

The conversion of a liquid into a gas.

What happens during the process of condensation in the hydrologic cycle?

Water vapor in the air cools and forms droplets, creating clouds.

How do clouds contribute to the hydrologic cycle?

Clouds move water around the globe and eventually release precipitation.

What process pulls water across the land to the lowest point?

Runoff.

Why are oceans important in the hydrologic cycle?

They are the largest reservoir of liquid water and contribute to weather and life on Earth.

What causes the oceans to be salty?

As water runs to the ocean, it erodes minerals like salt from soil; evaporation leaves the salt behind.

What is evapotranspiration?

The process through which plants absorb water and then release it as vapor into the atmosphere.

What major political and ecological problem is caused by CO2 release?

Global climate change.

What happens to carbon during photosynthesis in plants?

Plants absorb carbon dioxide from the atmosphere and convert it into energy and biomass.

What are fossil fuels?

Carbon-rich geological deposits formed from the remains of dead organisms.

How does the carbon cycle affect the Earth's climate?

Excess carbon in the atmosphere increases greenhouse gases, leading to warming.

What is permafrost?

Ground that is frozen year-round, containing carbon reserves trapped in dead plant matter.

What can result from the melting of permafrost?

Release of large amounts of carbon dioxide and methane into the atmosphere.

What effect does burning fossil fuels have on carbon reserves?

It releases carbon that has been stored underground for millions of years, increasing atmospheric CO2 levels.

What is the significance of the phrase 'the universe is a great recycler'?

It summarizes that all matter and energy on Earth have existed since the Big Bang and is constantly being repurposed.