California's future as a food producer for the rest of the U.S. is tied to its water, particularly to the fresh water supply in the Sacramento-San Joaquin Delta, says Jeff Mount. Mount said over time, the levees have weakened and the ecosystem has declined - and the state will have to make difficult choices to restore the delta.

Dee Boersma said penguins can't find food as easily because of the effects of warm water on the fish they eat. Warming ocean temperatures, she said, have altered sex ratios in some populations of the fish they eat, creating more males.

Dr. Thomas Karl told EarthSky that the large-scale burning of fossil fuels by humans amounts to treating our planet like a giant laboratory.

Monarch butterflies of eastern and central North America migrate each fall, over great distances, to the same winter homes of their great-great grandparents.

As you sit on the runway, your plane is already moving at the same speed Earth spins because the Earth is rotating.

"To understand any process," said Robin Bell , "you have to understand it from start to end. And what we want to be able to do with ice sheets is actually model how they grow and how they collapse."

Kathy Jacobs told EarthSky that we'll all have to adapt to climate extremes by using water more sustainably. But sustainable water use will mean different things in different places.

Today is the day on which we begin consuming more resources than Earth is producing - and producing more waste than Earth can absorb - for 2009.

Many animals can get as big as their environment and diet allow.

Flames get their "tongue-like" shapes from the way burning gases move and interact under earthly gravity.