It is unclear whether the inhabitants of Earth would be able to adapt to and survive this new climate.
The pro-fossil fuel U.S. event will take place as world leaders work to cap emissions and prevent "catastrophic" global warming.
The Intergovernmental Panel on Climate Change report warned of dire consequences of a global average temperature increase of 1.5 Celsius.
"Change is coming whether they like it or not," said Greta Thunberg.
"For many people, regions [and] even countries, this is already a matter of life and death."
"The continuation of civilizations and the natural world upon which we depend is in your hands," Attenborough told leaders.
The president appeared to confuse the concepts of weather and climate.
Gates worked to develop a type of "super coral" capable of withstanding the effects of climate change.
Water levels rose by more than 5 feet Monday.
In addition, 20 percent of the Amazon has disappeared in just 50 years.
Coastal villages are washing into the Bering Sea, trees are sprouting in the tundra and shipping lanes are opening in an ocean that was once locked in ice.
New York Democratic congressional primary winner Alexandria Ocasio-Cortez compared the "existential threat" posed by climate change to that of Nazi Germany during World War II.
Pando is a unique "forest of one tree" covering some 106 acres of the Fishlake National Forest in Utah.
Cherry blossoms are usually associated with spring in Japan.
Loss of ice at the North Pole could shut down the Gulf Stream, plunging Northern Europe and Scandinavia into a deep freeze.
"It's going to be challenging, obviously," the Arizona senator said. "That report that came out is pretty dire."
Egyptian blue is considered to be the first synthetic pigment.