Christiana Figueres, the lead U.N. negotiator of the Paris climate agreement, says the next decade is the most important in the history of humanity.
An expert tells us that it's possible to find the positive in any situation.
The founders of Life is Good took to the streets of Cambridge to spread positivity.
Science shows there are big benefits to looking on the bright side.
“I definitely don’t have that kind of optimism," the British TV host told Stephen Colbert.
“We have optimism that we’re going to win the war,” one activist said.
"A rich man's mantra," one Twitter user dubbed Trump's quote.
Looking for a mood boost right now? Try one of these simple happiness hacks.