Scientists made several advances in the treatment of Alzheimer's.
These included research into the impact of diet and exercise, discovery of a compound in marijuana that may impede the disease's progress, work on the potential effectiveness of mefanamic acid, currently used to treat menstrual pain, personalised treatment plans and certain antibiotic therapies all offered promising results.
After falling for around 100 years, the world's tiger population started to increase.
The same occurred for manatees and pandas. Wild wolves began to be seen again in Europe and humpback whales were removed from the endangered species list.
Researchers found that the hole above the Antarctic ozone layer has shrunk by more than 3.9 million square kilometres since 2006 and predict it could be fully closed by 2050.
A solar-powered plane flew around the world.
Portugal ran on renewable energy alone for four days. Costa Rica ran on renewable energy for more than 100 days and announced that it would attempt to go for a year without using fossil fuels.
California reached a total of six million homes powered by solar energy.
India announced a target of reforesting 12 per cent of its land, and in one day in July some 800,000 volunteers planted 50 million trees.
For the third year in a row global carbon emissions caused by burning fossil fuels did not grow.
China, the world's biggest polluter, banned new coal mines.
Its coal consumption, which began to fall in 2014, continued to drop.
It installed more than three times as much solar energy capacity than it had in the previous year.
For the first time in history, the death penalty became illegal in more than half the countries of the world.
Every sports underdog had its day: beginning the season at odds of 5000 to 1 to win, Leicester City took out the Football Association Premier league; the Chicago Cubs won baseball's World Series for the first item in 108 years; and something called "Ireland" beat the All Blacks for the first time in 111 years.
Bob Dylan finally won the Nobel Prize for literature, Adele started performing live again and Harry Potter fans got a new movie.
The Netflix drama series The Crown managed to make gripping and spectacular drama out of the life of Queen Elizabeth II, possibly the world's least charismatic woman, and made rabid fans of the most diehard republicans.
Aretha Franklin, Paul McCartney, Joni Mitchell, Van Morrison, Patti Smith and Brian Wilson did not die.
Spoiler Alert: you might want to get your tissues ready because none of those dinosaurs will get any younger in 2017.